| 1. |
- Aarup, Lasse Rye, et al.
(författare)
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The effect of different lung densities on the accuracy of various radiotherapy dose calculation methods: Implications for tumour coverage
- 2009
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 91:3, s. 405-414
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To evaluate against Monte-Carlo the performance of various dose calculations algorithms regarding lung turnout coverage in stereotactic body radiotherapy (SBRT) conditions. Materials and methods: Dose distributions in virtual lung phantoms have been calculated using four commercial Treatment Planning System (TPS) algorithms and one Monte Carlo (MC) system (EGSnrc). We compared the performance of the algorithms in calculating the target dose for different degrees of lung inflation. The phantoms had a cubic 'body' and 'lung' and a central 2-cm diameter spherical 'tumour' (the body and turnout have unit density). The lung tissue was assigned five densities (rho(lung)): 0.01, 0.1, 0.2, 0.4 and 1 g/cm(3). Four-field treatment plans were calculated with 6- and 18 MV narrow beams for each value of rho(lung). We considered the Pencil Beam Convolution (PBCEl) and the Analytical Anisotropic Algorithm (AAA(ECl)) from Varian Eclipse and the Pencil Beam Convolution (PBCOMP) and the Collapsed Cone Convolution (CCCOMP) algorithms from Oncentra MasterPlan. Results: When changing rho(lung) from 0.4 to 0.1 g/cm(3), the MC median target dose decreased from 89.2% to 74.9% for 6 MV and from 83.3% to 61.6% for 18 MV (of dose maximum in the homogenous case at both energies), while for both PB algorithms the median target dose was virtually independent of lung density. Conclusions: Both PB algorithms overestimated the target dose, the overestimation increasing as rho(lung) decreased. Concerning target dose, the AAA(ECl) and CCCOMP algorithms appear to be adequate alternatives to MC. (C) 2009 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and oncology 91 (2009) 405-414
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| 2. |
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| 3. |
- Bastholt, Lars, et al.
(författare)
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Phase I/II clinical and pharmacokinetic study evaluating a fully human monoclonal antibody against EGFr (HuMax-EGFr) in patients with advanced squamous cell carcinoma of the head and neck
- 2007
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 85:1, s. 24-28
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To assess safety, tolerability, pharmacokinetics and clinical activity of HuMax-EGFr in patients with SCCHN. Patients and methods: Twenty-eight patients with SCCHN were enrolled. The study comprised a single-dose escalation part for assessment of safety issues followed by a repeat dose extension including 4 weekly infusions at the same doses. Efficacy and metabolic response were evaluated according to RECIST by CT and FDG-PET. Results: Most frequently reported adverse event was rash. All but one event were CTC grade 1 or 2 and a dose-dependent relationship was indicated. Duration of skin reactions varied from few days to 2 months. No DLTs were observed and MTD was not reached. In the two highest dose groups, 7 of 11 patients obtained a PR or SD and 9 patients obtained metabolic PR or SD. Conclusions: HuMax-EGFr can be safety administered in doses up to 8 mg/kg, and preliminary data on tumour response are encouraging. (c) 2007 Elsevier Ireland Ltd.
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| 4. |
- Baumann, Pia, et al.
(författare)
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Stereotactic body radiotherapy for medically inoperable patients with stage I non-small cell lung cancer - a first report of toxicity related to COPD/CVD in a non-randomized prospective phase II study.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:3, s. 359-67
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: In a retrospective study using stereotactic body radiotherapy (SBRT) in medically inoperable patients with stage I NSCLC we previously reported a local control rate of 88% utilizing a median dose of 15Gyx3. This report records the toxicity encountered in a prospective phase II trial, and its relation to coexisting chronic obstructive pulmonary disease (COPD) and cardio vascular disease (CVD). MATERIAL AND METHODS: Sixty patients were entered in the study between August 2003 and September 2005. Fifty-seven patients (T1 65%, T2 35%) with a median age of 75 years (59-87 years) were evaluable. The baseline mean FEV1% was 64% and median Karnofsky index was 80. A total dose of 45Gy was delivered in three fractions at the 67% isodose of the PTV. Clinical, pulmonary and radiological evaluations were made at 6 weeks, 3, 6, 9, 12, 18, and 36 months post-SBRT. Toxicity was graded according to CTC v2.0 and performance status was graded according to the Karnofsky scale. RESULTS: At a median follow-up of 23 months, 2 patients had relapsed locally. No grade 4 or 5 toxicity was reported. Grade 3 toxicity was seen in 12 patients (21%). There was no significant decline of FEV1% during follow-up. Low grade pneumonitis developed to the same extent in the CVD 3/17 (18%) and COPD 7/40 (18%) groups. The incidence of fibrosis was 9/17 (53%) and pleural effusions was 8/17 (47%) in the CVD group compared with 13/40 (33%) and 5/40 (13%) in the COPD group. CONCLUSION: SBRT for stage I NSCLC patients who are medically inoperable because of COPD and CVD results in a favourable local control rate with a low incidence of grade 3 and no grade 4 or 5 toxicity.
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| 5. |
- Bentzen, Søren M., et al.
(författare)
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Towards evidence-based guidelines for radiotherapy infrastructure and staffing needs in Europe : the ESTRO QUARTS project
- 2005
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 75:3, s. 355-65
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Adequate and equitable access to radiotherapy (RT) must be a reasonable health care goal for the EU. However, there are large variations among the EU countries and even regional variations within countries in the provision of RT. In this report, we combine the best available evidence on the indications for RT with national epidemiological data to arrive at estimates for the appropriate level of RT infrastructure in the 25 EU countries. PATIENTS AND METHODS: Data from three systematic overviews of the best available evidence for the indication for RT in 23 main cancer types are combined with epidemiological data from the EUCAN and GLOBOCAN databases on the crude incidence of each of these cancers in the 25 EU countries. Together with published benchmarks for accelerator throughput this allows estimation of the number of linear accelerators per million people required to facilitate appropriate RT utilization rates in each country. Where possible, the estimates are compared with the detailed data available from Sweden. RESULTS: The crude incidence of the main cancer types shows large variation among the 25 EU countries. This reflects in part differences in exposure to aetiological risk factors and partly differences among the countries in population age structure. Correspondingly, the estimate of the required number of linear accelerators per million people showed considerable variation: ranging from 4.0 in Cyprus to 8.1 in Hungary. The average for the 25 countries was 5.9 per million people. These estimates were compared with available national guidelines and actual data on RT infrastructure and large shortfalls were found in many countries. Implications for health economics and capacity planning are briefly discussed. CONCLUSIONS: The QUARTS project has developed a model that establishes a direct and transparent link between epidemiological data and indications for RT based on the best available evidence. Comparison of the model estimates with current levels of RT infrastructure has revealed major inequalities in provision of RT in the 25 EU countries. Continuation of this study is recommended as a way of improving RT provision on rational grounds throughout the European community and as a model for health care planning in the EU.
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| 6. |
- Bohsung, J, et al.
(författare)
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IMRT treatment planning - A comparative inter-system and intor-centre planning exercise of the ESTRO QUASIMODO group
- 2005
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 76:3, s. 354-361
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: The purpose of this work was a comparison of realistic IMRT plans based on the same CT-image data set and a common predefined set of dose objectives for the planning target volume and the organs at risk. This work was part of the larger European QUASIMODO IMRT verification project. Materials and methods: Eleven IMRT. plans were produced by nine different European groups, each applying a representative set of. clinically used IMRT treatment planning systems. The plans produced were to be deliverable in a clinically acceptable treatment time with the local technical equipment. All plans were characterized using a set of different quality measures such as dose-volume histograms, number of monitor units and treatment time. Results: Only one plan was able to fulfil all dose objectives strictly; six plans failed some of the objectives but were still considered to be clinically acceptable; four plans were not able to reach the objectives. Additional quality scores such as the number of monitor units and treatment time showed large variations, which mainly depend on the delivery technique. Conclusion: The presented planning study showed that with nearly all presently available IMRT planning and delivery systems comparable dose distributions could be achieved if the planning goals are clearly defined in advance.
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| 7. |
- Carlsson Tedgren, Åsa, 1968-, et al.
(författare)
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Audit on source strength determination for HDR and PDR 192Ir brachytherapy in Sweden
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 86:1, s. 126-130
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: To investigate the status of source strength determination in terms of reference air kerma rate (RAKR) for HDR and PDR 192Ir brachytherapy in Sweden. Materials and methods: RAKR was determined in each of the 14 Swedish afterloaders, using calibrated equipment from the Swedish Secondary Standard Dosimetry Laboratory. Results: Values of RAKR from the external audit, the hospitals and vendors agreed within the uncertainty limits guaranteed by the vendors. Conclusions: The accuracy in RAKR determination has increased over the last years as a result of increased availability of interpolation standards for HDR 192Ir and the increased use of robust well-type ion chambers designed for brachytherapy. It is recommended to establish a ratio between the RAKR value from own measurements at the hospital and that of the vendor since such a ratio embeds constant systematic differences due to e.g. varying traceability and therefore has the potential of being less uncertain than the RAKR alone. Traceability to primary standards for HDR 192Ir sources will in the future significantly decrease the uncertainty in RAKR of 192Ir brachytherapy. © 2007 Elsevier Ireland Ltd. All rights reserved.
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| 8. |
- Carlsson Tedgren, Åsa, et al.
(författare)
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Experience from long-term monitoring of RAKR ratios in Ir-192 brachytherapy
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 89:2, s. 217-221
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Tidskriftsartikel (refereegranskat)abstract
- Background: Ratios of values of brachytherapy source strengths, as measured by hospitals and vendors, comprise constant differences as, e.g., systematic errors in ion chamber calibration factors and measurement setup. Such ratios therefore have the potential to reveal the systematic changes in routines or calibration services at either the hospital or the vendor laboratory, which could otherwise be hidden by the uncertainty in the source strength values. Methods: The RAKR of each new source in 13 afterloading units at five hospitals were measured by well-type ion chambers and compared to values for the same source stated on vendor certificates. Results: Differences from unity in the ratios of RAKR values determined by hospitals and vendors are most often small and stable around their mean values to within +/- 11.5%. Larger deviations are rare but occur. A decreasing ratio, seen at two hospitals for the same source, was useful in detecting an erroneous pressure gauge at the vendors site. Conclusions: Establishing a mean ratio of RAKR values, as measured at the hospital and supplied on the vendor certificate, and monitoring this as a function of time are an easy way for the early detection of problems with equipment or routines at either the hospital or the vendor site.
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| 9. |
- Fokstuen, Tone, et al.
(författare)
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Postoperative morbidity and mortality in relation to leukocyte counts and time to surgery after short-course preoperative radiotherapy for rectal cancer
- 2009
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 93:2, s. 293-297
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Preoperative radiotherapy for rectal cancer decreases local recurrence rates, but increases postoperative complications. Impaired postoperative leukocyte reaction after preoperative short-course radiotherapy has been reported. The aim was to assess postoperative morbidity and mortality in relation to leukocyte reaction and the time interval between radiotherapy and surgery. MATERIALS AND METHODS: A retrospective analysis of patients included in the Stockholm I and II trials, randomising patients to surgery alone or to 5 x 5 Gy with immediate surgery, identified pre- and postoperative leukocyte values for 274 patients. RESULTS: In the surgery alone group (n=144), all but three patients (2%) reacted with leukocytosis (ratio post/preoperative >1.0) on day 1 and all but 9 (6%) on day 5. In the radiotherapy group (n=130), 40 (31%) became leukopenic (<4 x 10(9) cells/L) after radiotherapy, 29 (22%) reacted abnormally (leukopenia or ratio < or =1.0) on day 1 and 66 (51%) on day 5 (all p<0.001). Preoperative leukocyte counts did not influence postoperative morbidity, but a poor response on day 1 increased the risk of sepsis (p<0.05) and mortality (6/29 (21%) vs. 6/101 (6%), p<0.05). An interval of 10 days or more between the start of radiotherapy and surgery also had an impact on mortality; 6/17 (35%) vs. 6/113 (5%), p=0.001. In a logistic regression analysis, the time interval and age were independent predictors of mortality. CONCLUSIONS: Impaired postoperative leukocyte reaction is frequent after short-course radiotherapy and increases the risk of postoperative complications and death. A longer than recommended radiotherapy-surgery interval also appears to be detrimental for postoperative death, independently of leukocyte response.
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| 10. |
- Georg, Dietmar, et al.
(författare)
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Clinical evaluation of monitor unit software and the application of action levels
- 2007
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 85:2, s. 306-315
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was the clinical evaluation of an independent dose and monitor unit verification (MUV) software which is based on sophisticated semi-analytical modelling. The software was developed within the framework of an ESTRO project. Finally, consistent handling of dose calculation deviations applying individual action levels is discussed. MATERIALS AND METHODS: A Matlab-based software ("MUV") was distributed to five well-established treatment centres in Europe (Vienna, Graz, Basel, Copenhagen, and Umeå) and evaluated as a quality assurance (QA) tool in clinical routine. Results were acquired for 226 individual treatment plans including a total of 815 radiation fields. About 150 beam verification measurements were performed for a portion of the individual treatment plans, mainly with time variable fluence patterns. The deviations between dose calculations performed with a treatment planning system (TPS) and the MUV software were scored with respect to treatment area, treatment technique, geometrical depth, radiological depth, etc. RESULTS: In general good agreement was found between calculations performed with the different TPSs and MUV, with a mean deviation per field of 0.2+/-3.5% (1 SD) and mean deviations of 0.2+/-2.2% for composite treatment plans. For pelvic treatments less than 10% of all fields showed deviations larger than 3%. In general, when using the radiological depth for verification calculations the results and the spread in the results improved significantly, especially for head-and-neck and for thorax treatments. For IMRT head-and-neck beams, mean deviations between MUV and the local TPS were -1.0+/-7.3% for dynamic, and -1.3+/-3.2% for step-and-shoot IMRT delivery. For dynamic IMRT beams in the pelvis good agreement was obtained between MUV and the local TPS (mean: -1.6+/-1.5%). Treatment site and treatment technique dependent action levels between +/-3% and +/-5% seem to be clinically realistic if a radiological depth correction is performed, even for dynamic wedges and IMRT. CONCLUSION: The software MUV is well suited for patient specific treatment plan QA applications and can handle all currently available treatment techniques that can be applied with standard linear accelerators. The highly sophisticated dose calculation model implemented in MUV allows investigation of systematic TPS deviations by performing calculations in homogeneous conditions
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| 11. |
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| 12. |
- Henriksson, Roger, et al.
(författare)
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Boron neutron capture therapy (BNCT) for glioblastoma multiforme : a phase II study evaluating a prolonged high-dose of boronophenylalanine (BPA)
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:2, s. 183-91
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: To evaluate the efficacy and safety of boron neutron capture therapy (BNCT) for glioblastoma multiforme (GBM) using a novel protocol for the boronophenylalanine-fructose (BPA-F) infusion. PATIENT AND METHODS: This phase II study included 30 patients, 26-69 years old, with a good performance status of which 27 have undergone debulking surgery. BPA-F (900 mg BPA/kg body weight) was given i.v. over 6h. Neutron irradiation started 2h after the completion of the infusion. Follow-up reports were monitored by an independent clinical research institute. RESULTS: The boron-blood concentration during irradiation was 15.2-33.7 microg/g. The average weighted absorbed dose to normal brain was 3.2-6.1 Gy (W). The minimum dose to the tumour volume ranged from 15.4 to 54.3 Gy (W). Seven patients suffered from seizures, 8 from skin/mucous problem, 5 patients were stricken by thromboembolism and 4 from abdominal disturbances in close relation to BNCT. Four patients displayed 9 episodes of grade 3-4 events (WHO). At the time for follow-up, minimum ten months, 23 out of the 29 evaluable patients were dead. The median time from BNCT treatment to tumour progression was 5.8 months and the median survival time after BNCT was 14.2 months. Following progression, 13 patients were given temozolomide, two patients were re-irradiated, and two were re-operated. Patients treated with temozolomide lived considerably longer (17.7 vs. 11.6 months). The quality of life analysis demonstrated a progressive deterioration after BNCT. CONCLUSION: Although, the efficacy of BNCT in the present protocol seems to be comparable with conventional radiotherapy and the treatment time is shorter, the observed side effects and the requirement of complex infrastructure and higher resources emphasize the need of further phase I and II studies, especially directed to improve the accumulation of (10)B in tumour cells.
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| 13. |
- Johansson, Bengt, 1958-, et al.
(författare)
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Pulsed dose rate brachytherapy as the sole adjuvant radiotherapy after breast-conserving surgery of T1-T2 breast cancer : first long time results from a clinical study
- 2009
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Ingår i: Radiotherapy and Oncology. - Amsterdam : Elsevier. - 0167-8140 .- 1879-0887. ; 90:1, s. 30-35
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: To evaluate the long time outcome with regard to local tumour control, cosmetic outcome and side effects of a short (5 days) accelerated interstitial brachytherapy treatment delivered to the surroundings of the operated sector. PATIENTS AND METHODS: Between 1993 and 2003 we treated 50 women with early T1 and T2 breast cancer. Radical sector resection was performed and followed later with an interstitial pulsed dose rate (PDR) brachytherapy of 50Gy in 5 days. The treatment was centred on the tumour with a margin of 30mm. One patient was treated bilaterally. The patients were followed for a median of 86 (32-126) months. RESULTS: Ipsilateral breast cancer recurrence was seen in 3 patients (6%). Two of them occurred outside the treated volume. The 5- and 7-year rates of actuarial local control were 96% and 96%, respectively, overall survival 88% and 85%, disease free survival 88% and 88%, respectively. A dosimetrical analysis showed that the partial breast irradiation covered a median of 31% of the total breast volume. Fat necrosis was seen in 12% and local (moderate-strong) fibrosis in 26% of the patients. Independent cosmetic scoring showed good or excellent result in 56% of the patients. CONCLUSIONS: Local outcome is favourable and very similar to other published studies of accelerated partial breast irradiation. Our long time cosmetic results are lower than other published results.
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| 14. |
- Johansson, Karl-Axel, et al.
(författare)
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The quality assurance process for the ARTSCAN head and neck study - a practical interactive approach for QA in 3DCRT and IMRT.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:2, s. 290-9
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Tidskriftsartikel (refereegranskat)abstract
- AIM: This paper describes the quality assurance (QA) work performed in the Swedish multicenter ARTSCAN (Accelerated RadioTherapy of Squamous cell CArcinomas in the head and Neck) trial to guarantee high quality in a multicenter study which involved modern radiotherapy such as 3DCRT or IMRT. MATERIALS AND METHODS: The study was closed in June 2006 with 750 randomised patients. Radiation therapy-related data for every patient were sent by each participating centre to the QA office where all trial data were reviewed, analysed and stored. In case of any deviation from the protocol, an interactive process was started between the QA office and the local responsible clinician and/or physicist to increase the compliance to the protocol for future randomised patients. Meetings and workshops were held on a regular basis for discussions on various trial-related issues and for the QA office to report on updated results. RESULTS AND DISCUSSION: This review covers the 734 patients out of a total of 750 who had entered the study. Deviations early in the study were corrected so that the overall compliance to the protocol was very high. There were only negligible variations in doses and dose distributions to target volumes for each specific site and stage. The quality of the treatments was high. Furthermore, an extensive database of treatment parameters was accumulated for future dose-volume vs. endpoint evaluations. CONCLUSIONS: This comprehensive QA programme increased the probability to draw firm conclusions from our study and may serve as a concept for QA work in future radiotherapy trials where comparatively small effects are searched for in a heterogeneous tumour population.
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| 15. |
- Kragl, Gabriele, et al.
(författare)
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Dosimetric characteristics of 6 and 10 MV unflattened photon beams
- 2009
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 93:1, s. 141-146
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To determine dosimetric properties of unflattened megavoltage photon beams. Materials and methods: Dosimetric data including depth dose, profiles, output factors and phantom scatter factors from three different beam qualities provided by Elekta Precise linacs, operated with and without flattening filter were examined. Additional measurements of leaf transmission, leakage radiation and surface dose were performed. In flattening filter free (FFF) mode a 6-mm thick copper filter was placed into the beam to stabilize it. Results: Depths of dose maxima for flattened and unflattened beams did not deviate by more than 2 mm and penumbral widths agreed within 1 mm. In FFF mode the collimator exchange effect was found to be on average 0.3% for rectangular fields. Between maximum and minimum field size head scatter factors of unflattened beams showed on average 40% and 56% less variation for 6 and 10 MV beams than conventional beams. Phantom scatter factors for FFF beams differed up to 4% from the published reference data. For field sizes smaller than 15 cm, surface doses relative to the dose at d(max) increased for unflattened beams with maximum differences of 7% at 6 MV and 25% at 10 MV for a 5 x 5 cm(2) field. For a 30 x 30 cm(2) field, relative surface dose decreased by about 10% for FFF beams. Leaf transmission on the central axis was 0.3% and 0.4% lower for unflattened 6 and 10 MV beams, respectively. Leakage radiation was reduced by 52% for 6 MV and by 65% for 10 MV unflattened beams. Conclusions: The results of the study were independently confirmed at two radiotherapy centres. Phantom scatter reference data need to be reconsidered for medical accelerators operated without a flattening filter. (C) 2009 Elsevier Ireland Ltd. All rights reserved. Radiotherapy and Oncology 93 (2009) 141-146
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| 16. |
- Lundkvist, Jonas, et al.
(författare)
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Economic evaluation of proton radiation therapy in the treatment of breast cancer
- 2005
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 75:2, s. 179-85
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Proton beam therapy offers potential clinical advantages compared with conventional radiation therapy for many cancer patients. The benefits are mainly a result of a more favourable dose distribution. The treatment cost with proton radiation is higher than for conventional radiation, mainly due to the large investment cost of building a proton therapy facility. It is therefore important to evaluate whether the medical benefits of proton therapy are large enough to justify the higher treatment costs, compared with conventional radiation therapy. PATIENTS AND METHODS: The cost-effectiveness of proton therapy in the treatment of 55-year old women with left-sided breast cancer was assessed. A Markov cohort simulation model was used to simulate the life of patients diagnosed with breast cancers and treated with radiation. Cost and quality adjusted life years (QALYs) were the primary outcome measures. RESULTS: The study found a cost per QALY gained of 67,000 Euro for the base case analysis of an average breast cancer patient. The cost per QALY gained would, however, be considerably lower if a population with high-risk of developing cardiac disease was treated. Sensitivity analyses showed that the results were stable and that the risk of cardiac disease was the most important parameter. CONCLUSIONS: The results indicate that proton therapy for breast cancer can be cost-effective if appropriate risk groups are chosen as targets for the therapy.
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| 17. |
- Lööf, Jasmine, et al.
(författare)
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Significance of an exon 2 G4C14-to-A4T14 polymorphism in the p73 gene on survival in rectal cancer patients with or without preoperative radiotherapy
- 2009
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 92:2, s. 215-220
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: An exon 2 G4C14→A4T14 polymorphism in the p73 gene was shown to be related to survival in several types of cancers, including colorectal cancer. The purpose was to investigate if this polymorphism was related to survival in rectal cancer patients with or without preoperative radiotherapy. Material and Methods: DNA extracted from tissue of 138 rectal cancer patients that received preoperative radiotherapy or had surgery alone was typed for the polymorphism by PCR using confronting two-pair primers. Results: Among patients, 69% had GC/GC genotype, 27% GC/AT and 4% AT/AT. In the radiotherapy group, patients carrying the AT (GC/AT+AT/AT) allele had stronger expression of p53 (p=0.001) and survivin protein (p=0.03) than those carrying the GC/GC genotype. Further, among patients receiving preoperative radiotherapy the GC/GC genotype tended to be related to better survival (p=0.20). Patients with GC/GC genotype, along with negative p53 and weak survivin expression showed better survival than the other patients (p=0.03), even after adjusting for TNM stage and tumor differentiation (p=0.01, RR, 7.63, 95% CI, 1.50-38.74). In the non-radiotherapy group, the polymorphism was not related to survival (p=0.74). Conclusions: Results suggest that the p73 G4C14→A4T14 polymorphism could be one factor influencing outcome of preoperative radiotherapy in rectal cancer patients.
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| 18. |
- Morgan, AM, et al.
(författare)
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Clinical implications of the implementation of advanced treatment planning algorithms for thoracic treatments
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 86:1, s. 48-54
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: Radiotherapy treatment planning algorithms continue to develop and current planning systems typically offer simpler, but faster, algorithms, which may be 2, 2.5 or 3D in modelling scatter, but which do not model electron transport (type a) and more accurate algorithms which aim to be fully 3D, i.e. which model 3D scatter and also model electron transport (type b). A range of comparative planning studies and experiments indicate that the main situation where the changes are significant between the two types of algorithm is where lung tissue is involved. However, more generally, interface areas between materials of different electron density and composition are expected to show differences between the two types of algorithms. These are likely to pose potentially significant clinical consequences when a centre changes from using older simpler algorithms to more accurate fully 3D ones and require careful consideration. MATERIALS AND METHODS: Some modelling is presented using the different type algorithms for a recently available novel design of linear accelerator treatment head, as part of the commissioning of that machine and in preparing for a change in TPS algorithm. The TPS data are compared to measurements and to Monte Carlo calculations. RESULTS AND DISCUSSION: The results add to the evidence of other studies that 3D planning techniques and type b dose calculation algorithms lead to systematic changes in computation and delivery of radiotherapy dose and in dose distributions, as compared to simpler methods, and that these changes are more pronounced in treatments involving lung tissue. The type b algorithms agree well with Monte Carlo modelling. CONCLUSIONS: Careful analysis of the changes is required before adopting new algorithms into clinical treatment planning practice. Discussion is needed between physicists and oncologists to fully understand the effects and potential consequences. These include changes in delivered dose to the reference point, to coverage of the PTV and to the dose distribution and also to dosimetric parameters used to constrain toxicity for lung, e.g. V20, and other tissues. There are consequences for assessment of dose-effect relationships and of parameters used in treatment planning decisions and this is an opportune time to re-evaluate this information.
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| 19. |
- Nyholm, Tufve, et al.
(författare)
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Photon pencil kernel parameterisation based on beam quality index
- 2006
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 78:3, s. 347-351
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Tidskriftsartikel (refereegranskat)abstract
- Background and purposeNew treatment techniques in radiotherapy employ increasing dose calculation complexity in treatment planning. For an adequate check of the results coming from a modern treatment planning system, clinical tools with almost the same degree of generality and accuracy as the planning system itself are needed. To fulfil this need we propose a photon pencil kernel parameterization based on a minimum of input data that can be used for phantom scatter calculations. Through scatter integration the pencil kernel model can calculate common parameters, such as TPR or phantom scatter factors, used in various dosimetric QA (quality assurance) procedures.Material and methodsThe proposed model originates from an already published radially parameterized pencil kernel. A depth parameterization of the pencil kernel parameters has been introduced, based on a large database containing commissioned beam data for a commercial treatment planning system. The entire pencil kernel model demands only one photon beam quality index, TPR20,10, as input.ResultsBy comparing the dose calculation results to the extensive experimental data set in the database, it has been possible to make a thorough analysis of the resulting accuracy. The errors in calculated doses, normalized to the reference geometry, are in most cases smaller than 2%.ConclusionsThe investigation shows that a pencil kernel model based only on TPR20,10 can be used for dosimetric verification purposes in megavoltage photon beams at depths below the range of contaminating electrons.
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| 22. |
- Pettersson, Niclas, 1974, et al.
(författare)
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Radiation-induced rib fractures after hypofractionated stereotactic body radiation therapy of non-small cell lung cancer: a dose- and volume-response analysis.
- 2009
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 1879-0887. ; 91:3, s. 360-8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: The aim of this study is to analyse the dose-response and the volume-response of radiation-induced rib fractures after hypofractionated stereotactic body radiation therapy (SBRT). MATERIALS AND METHODS: During the period 1998-2005, 68 patients with medically inoperable stage I non-small cell lung cancer (NSCLC) were treated with hypofractionated SBRT to 45 Gy in 3 fractions. Among the 33 patients with complete treatment records and radiographic follow-up exceeding 15 months (median: 29 months), 13 fractures were found in seven patients. Identifying all ribs receiving at least 21 Gy, 81 ribs (13 with and 68 without fracture) in 26 patients were separately contoured and their dose-volume histograms (DVHs) were obtained. The DVHs were assessed with the mean dose and cut-off models. Maximum likelihood estimation was used to fit dose-response and volume-response curves to each model. RESULTS: It was possible to quantify the risk of radiation-induced rib fracture using response curves and information contained in the DVHs. Absolute volumes provided better fits than relative volumes and dose-response curves were more suitable than volume-response curves. For the dose given by the 2 cm(3) cut-off volume, D(2 cm(3)), the logistic dose-response curve for three fractions was parameterised by D(50)=49.8 Gy and gamma(50)=2.05. Consequently, for a median follow-up of 29 months, if D(2 cm(3))<3 x 7.0 Gy the risk is close to 0, and the 5% and 50% risks are given by D(2 cm(3))=3 x 9.1 Gy and 3 x 16.6 Gy, respectively. CONCLUSIONS: In this group of patients, the risk for radiation-induced rib fracture following hypofractionated SBRT was related to the dose to 2 cm(3) of the rib.
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| 23. |
- Radu, Calin, et al.
(författare)
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Short-course preoperative radiotherapy with delayed surgery in rectal cancer : a retrospective study
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:3, s. 343-9
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: In the most advanced, non-resectable primary rectal cancers, conventional long-course radiotherapy (RT) (1.8-2Gyx25-28), frequently combined with chemotherapy, has been used since tumour regression is needed in order to allow a radical (R0) resection. In Uppsala, short-course 5x5Gy with planned delayed surgery has been used in patients with contraindications to long-course RT (+/-chemotherapy). The aim is to describe our experience of using this approach in patients not eligible for standard treatment. PATIENTS AND METHODS: During 2002 and 2005, 46 patients with non-resectable rectal cancer (+/-synchronous distant metastases) were treated with 5x5Gy and delayed surgery if possible. The clinical records were retrospectively evaluated. The first group (A) had no metastases (T4NXM0), whereas the other two groups (B+C) had metastases (T4NXM1). In group (B), the patients had predominantly loco-regional disease and were not candidates for combination chemotherapy (high age, co-morbidities), and in group (C) up-front combination chemotherapy was given, with the intention to have surgery of both the primary and the secondaries if sufficient regression at both sites were seen. RESULTS: The patients in the first two groups (A+B) were old (median 79 and 76 years, respectively), and had several co-morbidities. In group (C), median age was 63 years. The 5x5Gy RT was well tolerated by most patients, but grade IV diarrhoea was recorded in three elderly patients. One patient in the group (C) died from neutropenic fever. Many patients were reported to have less local symptoms after the treatment given. Delayed surgery was performed in all but nine patients. Radical surgery (R0+R1) was performed in 22 (92%) (group A), 4 (44%) (group B), and 6 (46%) (group C) patients, respectively. A pCR was seen in four patients (two in group A and two in group C). No postoperative deaths occurred. CONCLUSIONS: Considering the very high age and presence of co-morbidity, the 5x5Gy schedule is well tolerated. Further, considering the very advanced local stage, the schedule has considerable anti-tumour activity and can result in radical surgery in a high proportion of patients.
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| 24. |
- Simonsson, Martin, et al.
(författare)
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Low-dose hypersensitive gammaH2AX response and infrequent apoptosis in epidermis from radiotherapy patients.
- 2008
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Ingår i: Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 88:3, s. 388-97
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND PURPOSE: A low-dose hypersensitivity to radiation can be observed in vitro for many human cell types in terms of increased cell kill per dose unit for doses below 0.5Gy. Quantification of the double-strand break marker gammaH2AX in samples taken in clinical radiotherapy practice has the potential to provide important information about how induction and repair of severe DNA damage and apoptosis are linked to low-dose hypersensitivity. MATERIAL AND METHODS: The effects of exposure to low doses (0.05-1.1Gy) were investigated in skin biopsies taken from prostate cancer patients undergoing the first week of radiotherapy. gammaH2AX foci and apoptotic cells were visualised by immunohistochemistry and quantified by image analysis. RESULTS: The gammaH2AX foci pattern in biopsies taken 30min after a single fraction revealed a low-dose hypersensitivity below 0.3Gy (p=0.0009). The result was consistent for repeated fractions (p=0.00001). No decrease in foci numbers could be detected when comparing biopsies taken 30min and 2h after single fractions of 0.4 and 1.2Gy. The result was consistent for repeated fractions. Only 43 of 168,000 cells in total were identified as apoptotic, yet a dose dependency could be detected after 1week of radiotherapy (p=0.003). CONCLUSIONS: We describe a method based on gammaH2AX to study DNA damage response and apoptosis in a clinical setting. A gammaH2AX hypersensitive response to low doses can be observed in epidermal skin, already 30min following delivered fraction. A very low frequency of apoptosis in normal epithelium suggests that this effect is not an important part of the in vivo response to low doses.
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| 25. |
- Söderlund, Karin, 1979-, et al.
(författare)
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The BRCA1/BRCA2/Rad51 complex is a prognostic and predictive factor in early breast cancer
- 2007
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 84:3, s. 242-251
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Tidskriftsartikel (refereegranskat)abstract
- Background and Purpose: The breast cancer susceptibility genes BRCA1 and BRCA2 interact with Rad51, one of the central components in the homologous recombination repair pathway. This study evaluates the prognostic and predictive role of BRCA1, BRCA2 and Rad51, individually and as a complex, in breast cancer.Material and Methods: Expression of BRCA1, BRCA2 and Rad51 was investigated using immunohistochemistry in tumours from 224 women with early breast cancer, who were randomised to receive postoperative radiotherapy or adjuvant chemotherapy (CMF).Results: 53% (112/212) of the tumours had reduced expression of the BRCA1/BRCA2/Rad51 complex. Low expression correlated to high histologic grade (p=0.05). Patients with low expression of the complex developed significantly more local recurrences as compared to patients with high expression (RR=3.20, 95% C.I. 1.48-6.88, p=0.003). Expression of the BRCA1/BRCA2/Rad51 complex was an independent prognostic factor in multivariate analysis (p=0.03). Patients with low expression of the complex responded well to radiotherapy (RR=0.31, 95% C.I. 0.14-0.70, p=0.005), whereas patients with high expression had few local recurrences and no additional benefit from radiotherapy (RR=1.08, 95% C.I. 0.40-2.90, p=0.88).Conclusions: Low expression of the BRCA1/BRCA2/Rad51 complex is a marker of poor prognosis, but predicts good effect of radiotherapy in patients with early breast cancer.
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| 26. |
- Valentini, Vincenzo, et al.
(författare)
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Evidence and research in rectal cancer
- 2008
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 87:3, s. 449-474
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Forskningsöversikt (refereegranskat)abstract
- The main evidences of epidemiology, diagnostic imaging, pathology, surgery, radiotherapy, chemotherapy and follow-up are reviewed to optimize the routine treatment of rectal cancer according to a multidisciplinary approach. This paper reports on the knowledge shared between different specialists involved in the design and management of the multidisciplinary ESTRO Teaching Course on Rectal Cancer. The scenario of ongoing research is also addressed. In this time of changing treatments, it clearly appears that a common standard for large heterogeneous patient groups have to be substituted by more individualised therapies based on clinical-pathological features and very soon on molecular and genetic markers. Only trained multidisciplinary teams can face this new challenge and tailor the treatments according to the best scientific evidence for each patient.
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| 27. |
- Valentini, Vincenzo, et al.
(författare)
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Multidisciplinary Rectal Cancer Management : 2nd European Rectal Cancer Consensus Conference (EURECA-CC2)
- 2009
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 92:2, s. 148-163
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Forskningsöversikt (refereegranskat)abstract
- BACKGROUND AND PURPOSE: During the first decade of the 21st century a number of important European randomized studies were published. In order to help shape clinical practice based on best scientific evidence from the literature, the International Conference on 'Multidisciplinary Rectal Cancer Treatment: Looking for an European Consensus' (EURECA-CC2) was organized in Italy under the endorsement of European Society of Medical Oncology (ESMO), European Society of Surgical Oncology (ESSO), and European Society of Therapeutic Radiation Oncology (ESTRO). METHODS: Consensus was achieved using the Delphi method. The document was available to all Committee members as a web-based document customized for the consensus process. Eight chapters were identified: epidemiology, diagnostics, pathology, surgery, radiotherapy and chemotherapy, treatment toxicity and quality of life, follow-up, and research questions. Each chapter was subdivided by a topic, and a series of statements were developed. Each member commented and voted, sentence by sentence thrice. Sentences upon which an agreement was not reached after voting round # 2 were openly debated during a Consensus Conference in Perugia (Italy) from 11 December to 13 December 2008. A hand-held televoting system collected the opinions of both the Committee members and the audience after each debate. The Executive Committee scored percentage consensus based on three categories: "large consensus", "moderate consensus", and "minimum consensus". RESULTS: The total number of the voted sentences was 207. Of the 207, 86% achieved large consensus, 13% achieved moderate consensus, and only 3 (1%) resulted in minimum consensus. No statement was disagreed by more than 50% of the members. All chapters were voted on by at least 75% of the members, and the majority was voted on by >85%. CONCLUSIONS: This Consensus Conference represents an expertise opinion process that may help shape future programs, investigational protocols, and guidelines for staging and treatment of rectal cancer throughout Europe.
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| 28. |
- Wieslander, Elinore, et al.
(författare)
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A virtual-accelerator-based verification of a Monte Carlo dose calculation algorithm for electron beam treatment planning in clinical situations.
- 2007
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 1879-0887 .- 0167-8140. ; 82:2, s. 208-217
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose The introduction of Monte Carlo (MC) techniques for treatment planning and also for verification purposes will have considerable impact on the radiation therapy planning process. The aim of this work was to use a virtual accelerator to study the performance of a MC-based electron dose calculation algorithm, implemented in a commercial treatment planning system. Methods The performance in phantoms containing air and bone as well as in patient-specific geometries (thorax wall, nose, parotid gland and spinal cord) has been studied. Results The agreement between the virtual accelerator and the MC dose calculation algorithm is generally very good. A γ-evaluation with criteria of 0.03 Gy/3 mm (per Gy at the depth of maximum dose) shows that, even for the worst cases, only a small volume of about 1.5% has γ > 1.0. In the worst case, with the 0.02 Gy/2 mm criteria, about 92% of the volume receiving more than 0.85 Gy per 100 monitor units (MU) has γ-values <1.0. The corresponding value for the volume receiving more than 0.10 Gy/100 MU is about 98%. For the 18 MeV spinal-cord case, where a 6 × 20 cm2 insert is used, the TPS underestimates the dose outside the primary field due to inadequate modelling of the insert. Conclusion The possibility of dose calculations in typical patient cases makes the virtual accelerator a powerful tool for validation and evaluation of dose calculation algorithms present in treatment planning systems.
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| 29. |
- Åström, Lennart, et al.
(författare)
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Long-term outcome of high dose rate brachytherapy in radiotherapy of localised prostate cancer
- 2005
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 74:2, s. 157-161
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: High dose rate brachytherapy (HDR-BT) in prostate cancer (PC) is receiving increasing interest. The steep dose gradient gives a possibility to escalate the dose to the prostate. If the a/b ratio is low for PC, hypofractionation will be of advantage. A retrospective analysis of outcome in patients (pts) consecutively treated with combined HDR-BT and conformal external beam radiotherapy (ERT) was performed. Material and methods: Data from 214 pts treated consecutively from 1988 to 2000 were analysed. The median age was 64 years (50–77). Median follow up was 4 years (12–165 months). Pre-irradiatory endocrine therapy was given to 150 pts (70%). The pts were divided into low-, intermediate- and high (80/87/47 pts) risk groups according to the occurrence of none, one, or more risk factors defined by T-classification, PSA and histopathology. ERT was given with 2 Gy fractions to 50 Gy. HDR-BT consisted of two 10 Gy fractions. Results: Overall 5-year biochemical no evidence of disease (bNED) was 82%, and for the low-, intermediate-, and high-risk group bNED was 92, 88 and 61%, respectively. PSA-relapse was found in 17, local recurrence in 3 and distant metastases in 13 pts. Five pts died of PC. No recurrences were observed after 5 years. Severe late complications were few. Urethral stricture (13 pts) was the most frequent. No severe rectal complications were seen. Conclusion: Dose escalation with HDR-BT is safe and effective in radiotherapy of localised PC.
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