| 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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