| 1. |
- Ask, Anders, et al.
(författare)
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The potential of proton beam radiation therapy in head and neck cancer.
- 2005
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Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 876-80
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Tidskriftsartikel (refereegranskat)abstract
- A group of Swedish oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy. The estimations have been based on current statistics of tumour incidence, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours and normal tissues. In head and neck cancer, including thyroid cancer, it is assessed that at least 300 patients annually will gain sufficiently from proton beam therapy, both to improve tumour control and to decrease toxicity to compensate for the increased treatment costs using protons.
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| 2. |
- Glimelius, B., et al.
(författare)
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Number of patients potentially eligible for proton therapy
- 2005
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Ingår i: Acta Oncol. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:8, s. 836-49
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Tidskriftsartikel (refereegranskat)abstract
- A group of Swedish radiation oncologists and hospital physicists have estimated the number of patients in Sweden suitable for proton beam therapy in a facility where one of the principal aims is to facilitate randomized and other studies in which the advantage of protons can be shown and the magnitude of the differences compared with optimally administered conventional radiation treatment, also including intensity-modulated radiation therapy (IMRT) and brachytherapy, can be shown. The estimations have been based on current statistics of tumour incidence in Sweden, number of patients potentially eligible for radiation treatment, scientific support from clinical trials and model dose planning studies and knowledge of the dose-response relations of different tumours together with information on normal tissue complication rates. In Sweden, it is assessed that between 2200 and 2500 patients annually are eligible for proton beam therapy, and that for these patients the potential therapeutic benefit is so great as to justify the additional expense of proton therapy. This constitutes between 14-15% of all irradiated patients annually.
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| 3. |
- 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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| 4. |
- Karlsson, Mikael, et al.
(författare)
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"Distributed proton radiation therapy"--a new concept for advanced competence support.
- 2006
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Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 45:8, s. 1094-101
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Tidskriftsartikel (refereegranskat)abstract
- The increased interest in high precision radiation therapy is to a large extent driven by the potential of modern imaging technology. The aim of this project was to analyse how an expensive proton facility best could support a multi-centre health care system. We have developed a model for distributed expert collaboration where all clinical experts will work close to their patients in regional centres. Patients who are candidates for proton therapy will be examined and dose-planned at their regional clinic, discussed in a fully information supported video conference and digitally made available at the proton treatment facility. The proton facility itself will be placed near a communication centre easily reached by all patients where they will be treated under full responsibility of their own physician at the home clinic. This concept has been analysed in detail both with respect to the overall functionality and with respect to possible weaknesses. It was found that the concept of distributed radiation therapy, as proposed here, will offer a stable clinical solution for advanced radiation therapy. It will support the spread of knowledge, serve as a fully developed backup system and the concept will further serve as an efficient base for clinical research.
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| 5. |
- Mu, Xiangkui, 1972-
(författare)
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Clinical application of intensity and energy modulated radiotherapy with photon and electron beams
- 2005
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In modern, advanced radiotherapy (e.g. intensity modulated photon radiotherapy, IMXT) the delivery time for each fraction becomes prolonged to 10-20 minutes compared with the conventional, commonly 2-5 minutes. The biological effect of this prolongation is not fully known. The large number of beam directions in IMXT commonly leads to a large integral dose in the patient. Electrons would reduce the integral dose but are not suitable for treating deep-seated tumour, due to their limited penetration in tissues. By combining electron and photon beams, the dose distributions may be improved compared with either used alone. One obstacle for using electron beams in clinical routine is that there is no available treatment planning systems that optimise electron beam treatments in a similar way as for IMXT. Protons have an even more pronounced dose fall-off, larger penetration depth and less penumbra widening than electrons and are therefore more suitable for advanced radiotherapy. However, proton facilities optimised for advanced radiotherapy are not commonly available. In some instances electron beams may be an acceptable surrogate. The first part of this study is an experimental in vitro study where the situation in a tumour during fractionated radiotherapy is simulated. The effect of the prolonged fraction time is compared with the predictions by radiobiological models. The second part is a treatment planning study to analyse the mixing of electron and photon beams for at complex target volume in comparison with IMXT. In the next step a research version of an electron beam optimiser was used for the improvement of treatment plans. The aim was to develop a method for translating crude energy and intensity matrices for optimised electrons into a deliverable treatment plan without destroying the dose distribution. In the final part, different methods of treating the spinal canal in medulloblastoma were explored in a treatment planning study that was evaluated with biological models for estimating risks for late radiation effects. The effect on cell survival of prolonging fraction time at conventional doses/fraction is significant in an in vitro system. This effect is underestimated by biological models. Prolonging the fraction time will spare tissues with a fast DNA repair. Thus, there is a risk for sparing tumours. The mixed electron and photon beam technique has the potential to treat deep-seated tumours. Compared with IMXT the number of beams can be reduced and as a consequence, the time for each fraction could be kept shorter. The integral dose in the patient will also be lower. The mixed beam technique could potentially be further improved if automatic optimisation for electrons was available. The results suggest that optimisation and segmentation can be automated, and a deliverable treatment plan can be obtained with simple procedures without destroying the quality of the dose distribution. The integral dose in patients may lead to late radiation side effects. In childhood cancers the risk for development of radiation induced cancers is a reality and the integral dose outside the target volume should be minimised. Based on models for cancer induction, protons show the lowest risk while electrons have some benefit compared with different photon techniques. All methods are able to similarly well treat the target volume.
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| 6. |
- Mu, Xiangkui, et al.
(författare)
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Does electron and proton therapy reduce the risk of radiation induced cancer after spinal irradiation for childhood medulloblastoma? A comparative treatment planning study.
- 2005
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Ingår i: Acta oncologica (Stockholm, Sweden). - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 44:6, s. 554-62
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this treatment planning comparison study was to explore different spinal irradiation techniques with respect to the risk of late side-effects, particularly radiation-induced cancer. The radiotherapy techniques compared were conventional photon therapy, intensity modulated x-ray therapy (IMXT), conventional electron therapy, intensity/energy modulated electron therapy (IMET) and proton therapy (IMPT).CT images for radiotherapy use from five children, median age 8 and diagnosed with medulloblastoma, were selected for this study. Target volumes and organs at risk were defined in 3-D. Treatment plans using conventional photon therapy, IMXT, conventional electron therapy, IMET and IMPT were set up. The probability of normal tissue complication (NTCP) and the risk of cancer induction were calculated using models with parameters-sets taken from published data for the general population; dose data were taken from dose volume histograms (DVH).Similar dose distributions in the targets were achieved with all techniques but the absorbed doses in the organs-at-risk varied significantly between the different techniques. The NTCP models based on available data predicted very low probabilities for side-effects in all cases. However, the effective mean doses outside the target volumes, and thus the predicted risk of cancer induction, varied significantly between the techniques. The highest lifetime risk of secondary cancers was estimated for IMXT (30%). The lowest risk was found with IMPT (4%). The risks associated with conventional photon therapy, electron therapy and IMET were 20%, 21% and 15%, respectively.This model study shows that spinal irradiation of young children with photon and electron techniques results in a substantial risk of radiation-induced secondary cancers. Multiple beam IMXT seems to be associated with a particularly high risk of secondary cancer induction. To minimise this risk, IMPT should be the treatment of choice. If proton therapy is not available, advanced electron therapy may provide a better alternative.
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| 7. |
- Zackrisson, Björn, et al.
(författare)
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Mature results from a Swedish comparison study of conventional versus accelerated radiotherapy in head and neck squamous cell carcinoma - The ARTSCAN trial
- 2015
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Ingår i: Radiotherapy and Oncology. - : Elsevier BV. - 0167-8140 .- 1879-0887. ; 117:1, s. 99-105
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: This report contains the mature five-year data from the Swedish ARTSCAN trial including information on the influence of p16 positivity (p16+) for oropharyngeal cancers. Material and methods: Patients with previously untreated squamous cell carcinoma without distant metastases of the oral cavity, oropharynx, larynx (except T1-2, NO glottic cancers) and hypopharynx were included. Patients were randomised between accelerated fractionation (AF) (1.1 Gy + 2 Gy per day, 5 days/week for 4.5 weeks, total dose 68 Gy) and conventional fractionation (CF) (2 Gy per day, 5 days/week for 7 weeks, total dose 68 Gy). Human papillomavirus (HPV)-associated p16-expression was assessed retrospectively in tumour tissues from patients with oropharyngeal carcinoma. Results: There was no significant difference in loco-regional control (LRC) between AF and CF (log-rank test p = 0.75). LRC at 5 years was 65.5% for AF and 64.9% for CF. Overall survival (OS) was similar in both arms (p = 0.99). The estimated cancer specific survival (CSS) at 5 years was 62.2% (AF) and 63.3% (CF) (p = 0.99). 206 specimens were analysed for p16 with 153 specimens (74%) identified as p16+. P16 status did not discriminate for response to AF vs. CF with regard to LRC, OS or CSS. Patients with p16+ tumours had a statistically significant better overall prognosis compared with p16 tumours. Conclusion: This update confirms the results of the 2-year report. We failed to identify a positive effect resulting from AF with regards to LRC, OS and CSS. The addition of information on the HPV-associated p16 overexpression did not explain this lack of effect.
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| 8. |
- Zackrisson, Björn, et al.
(författare)
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Two-year results from a Swedish study on conventional versus accelerated radiotherapy in head and neck squamous cell carcinoma - The ARTSCAN study
- 2011
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Ingår i: Radiotherapy and Oncology. - : Elsevier. - 0167-8140 .- 1879-0887. ; 100:1, s. 41-48
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Tidskriftsartikel (refereegranskat)abstract
- Background and purpose: Studies on accelerated fractionation (AF) in head and neck cancer have shown increased local control and survival compared with conventional fractionation (CF), while others have been non-conclusive. In 1998 a national Swedish group decided to perform a randomised controlled clinical study of AF. Materials and methods: Patients with verified squamous cell carcinoma of the oral cavity, oropharynx, larynx (except glottic T1-T2, N0) and hypopharynx were included. Patients with prior chemotherapy or surgery were excluded. Patients were randomised to either CF (2Gy/day, 5days/week for 7 weeks, total dose 68Gy) or to AF (1.1Gy+2.0Gy/day, 5days/week for 4.5weeks, total dose 68Gy). An extensive quality assurance protocol was followed throughout the study. The primary end point was loco-regional tumour control (LRC) at two years after treatment. RESULTS: The study was closed in 2006 when 750 patients had been randomised. Eighty-three percent of the patients had stages III-IV disease. Forty eight percent had oropharyngeal, 21% laryngeal, 17% hypopharyngeal and 14% oral cancers. There were no significant differences regarding overall survival (OS) or LRC between the two regimens. The OS at two years was 68% for AF and 67% for CF. The corresponding figures for LRC were 71% and 67%, respectively. There was a trend towards improved LRC for oral cancers treated (p=0.07) and for large tumours (T3-T4) (p=0.07) treated with AF. The AF group had significantly worse acute reactions, while there was no significant increase in late effects. Conclusion: Overall the AF regimen did not prove to be more efficacious than CF. However, the trend towards improved results in AF for oral cancers needs to be further investigated.
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