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

ABSTRACT: 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 D50 (dose at 50% probability of control) and g50 (steepness), ?/? (dose-fractionation radiosensitivity), and repopulation parameters, dprolif and Tprolif , 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) D50 and g50 values were 62 (CI 53 - 66)?Gy and 1.6 (0.8 - 2.4). ADT patients showed lower values of D50 and g50 (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 ?/? was 1.4 (1.0 - 1.9)?Gy with p < 0.0001 for all patients. The median values of dproli f and Tprolif 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.

SUBMITTER: Tamponi M

PROVIDER: S-EPMC6592096 | biostudies-literature | 2019 Jun

REPOSITORIES: biostudies-literature

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

Tamponi Matteo M Gabriele Domenico D Maggio Angelo A Stasi Michele M Meloni Giovanni B GB Conti Maurizio M Gabriele Pietro P

The British journal of radiology 20190424 1098

<h4>Objective</h4>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.<h4>Methods</h4>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 ther ...[more]

PMID: 31017457

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

Publications

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

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