PURPOSE: To establish the alpha/beta ratio of bladder cancer from different radiotherapy schedules reported in the literature and provide guidelines for the design of new treatment schemes.
METHODS AND MATERIALS: Ten external beam radiotherapy (EBRT) and five brachytherapy schedules were selected. The biologically effective dose (BED) of each schedule was calculated. Logistic modeling was used to describe the relationship between 3-year local control (LC3y) and BED.
RESULTS: The estimated alpha/beta ratio was 13 Gy (95% confidence interval [CI], 2.5-69 Gy) for EBRT and 24 Gy (95% CI, 1.3-460 Gy) for EBRT and brachytherapy combined. There is evidence for an overall dose-response relationship. After an increase in total dose of 10 Gy, the odds of LC3y increase by a factor of 1.44 (95% CI, 1.23-1.70) for EBRT and 1.47 (95% CI, 1.25-1.72) for the data sets of EBRT and brachytherapy combined.
CONCLUSION: With the clinical data currently available, a reliable estimation of the alpha/beta ratio for bladder cancer is not feasible. It seems reasonable to use a conventional alpha/beta ratio of 10-15 Gy. Dose escalation could significantly increase local control. There is no evidence to support short overall treatment times or large fraction sizes in radiotherapy for bladder cancer.
|Number of pages||6|
|Journal||International journal of radiation oncology, biology, physics|
|Publication status||Published - 15 Mar 2006|