Prostate cancer dose-response, fractionation sensitivity and repopulation parameters evaluation from 25 international radiotherapy outcome data sets.

Autor: Tamponi M; 1 ATS, Sardinia Regional Health Service , Sassari , Italy., Gabriele D; 2 Institute of Radiological Sciences University of Sassari , Italy., Maggio A; 3 Medical Physics, Candiolo Cancer Institute - FPO , IRCCS, Candiolo (To) , Italy., Stasi M; 3 Medical Physics, Candiolo Cancer Institute - FPO , IRCCS, Candiolo (To) , Italy., Meloni GB; 2 Institute of Radiological Sciences University of Sassari , Italy., Conti M; 2 Institute of Radiological Sciences University of Sassari , Italy.; 4 Department of Diagnostic Imaging, AOU, University Hospital Trust of Sassari , Italy., Gabriele P; 5 Radiation Therapy, Candiolo Cancer Institute - FPO , IRCCS, Candiolo (To) , Italy.
Jazyk: angličtina
Zdroj: The British journal of radiology [Br J Radiol] 2019 Jun; Vol. 92 (1098), pp. 20180823. Date of Electronic Publication: 2019 Apr 24.
DOI: 10.1259/bjr.20180823
Abstrakt: Objective: This study was undertaken to model the biochemical free survival at 5 years and to evaluate the parameters defining dose-response curve, dose-fractionation radiosensitivity and repopulation.
Methods: It was carried out a literature search on Pubmed to retrieve data sets of patients treated with external beam radiation therapy of 1.8-4.0 Gy per fraction and overall treatment time of 3 to 10 weeks. 10 groups were identified, based on risk class and androgen deprivation therapy (ADT). Dose-response curve D 50 (dose at 50% probability of control) and g 50 (steepness), α/β (dose-fractionation radiosensitivity), and repopulation parameters, d prolif and T prolif , were calculated. Bootstrap-based cross-validation was performed and median and 95% CI (confidence interval) were evaluated.
Results: 25 data sets, including 20,310 patients, were considered. The median (95% CI) D 50 and g 50 values were 62 (CI 53 - 66) Gy and 1.6 (0.8 - 2.4). ADT patients showed lower values of D 50 and g 50 (57 ± 5 Gy and 1.1 ± 0.4) compared to no-ADT patients (65 ± 2 Gy and 2.3 ± 0.6), with p < 0.0001 and p = 0.002. If we did not consider any dependence on overall treatment time, the median (95% CI) value of α/β was 1.4 (1.0 - 1.9) Gy with p < 0.0001 for all patients. The median values of d proli f and T prolif were 0.0 to 0.3 Gy/d and 18-40 days.
Conclusion: Dose-response curve resulted dependent on risk class and ADT, with higher steepness for no-ADT patients. Low values of dose-fractionation radiosensitivity were found, supporting the use of moderate hypofractionated radiotherapy in each risk class. A limited dependence on repopulation was observed.
Advances in Knowledge: Prostate cancer response to moderate hypofractionated radiotherapy was reliably quantified considering risk class and androgen deprivation therapy.
Databáze: MEDLINE
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