Title |
Will intrafraction repair have negative consequences on extreme hypofractionation in prostate radiation therapy?
|
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Published in |
British Journal of Radiology, October 2015
|
DOI | 10.1259/bjr.20150588 |
Pubmed ID | |
Authors |
Alexandru Dasu, Iuliana Toma-Dasu |
Abstract |
The present study aims to investigate the impact of increasing fraction delivery time on the outcome of hypofractionated radiation therapy for prostate cancer. Mono-exponential and bi-exponential repair models have been used for prostate patients to study the loss of biochemical control at 5 years for several clinically-relevant irradiation times. The theoretical predictions were compared with newly reported clinical results from 4607 patients undergoing conventionally-fractionated and hypofractionated prostate radiation therapy. Time-demanding irradiation techniques appear to lead to biochemical control rates that sometimes are about 10-20 percentage points below predictions that neglect intra-fraction repair. This difference appears to be of the same order of magnitude as that predicted by moderately-slow to slow repair taking place during the irradiation time. The impact is largest for the patient risk groups receiving doses corresponding to the steepest part of the dose-response curve. In contrast, for treatment techniques requiring irradiation times shorter than about 20 minutes, the impact of intra-fraction repair appears to be much smaller and probably difficult to be observed in the light of other sources of uncertainty in clinical data. Neglecting intra-fraction repair might overestimate the effectiveness of some treatment schedules and could also influence any subsequent estimations of fractionation sensitivity for prostate tumours. Advances in knowledge: The effect of intra-fraction repair for prostate cancer should be taken into account for long irradiation sessions as might be expected from scanned beams and/or from multiple intra-fraction imaging sessions to check the positioning of the patient. |
Mendeley readers
Geographical breakdown
Country | Count | As % |
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Unknown | 19 | 100% |
Demographic breakdown
Readers by professional status | Count | As % |
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Student > Doctoral Student | 3 | 16% |
Researcher | 3 | 16% |
Student > Postgraduate | 2 | 11% |
Student > Master | 2 | 11% |
Student > Ph. D. Student | 1 | 5% |
Other | 3 | 16% |
Unknown | 5 | 26% |
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Computer Science | 1 | 5% |
Psychology | 1 | 5% |
Unknown | 7 | 37% |