To evaluate the correlations between the changes in the quality-of-life scores and the dose–volume histogram parameters in patients receiving high-dose-rate brachytherapy combined with hypofractionated external beam radiation therapy for localized prostate cancer.Methods
Among the patients who were treated with high-dose-rate brachytherapy (18 Gy in two fractions) combined with hypofractionated external beam radiation therapy (45 Gy in 15 fractions), the data of 118 consecutive patients followed up for >24 months were prospectively analyzed. The disease-specific quality of life was assessed using the expanded prostate cancer index composite, and the acute genitourinary toxicities were graded based on the Radiation Therapy Oncology Group and European Organization for Research and Treatment of Cancer Toxicity criteria.Results
The median follow-up duration was 58 months (42–84 months). Thirteen patients (11%) developed Grade 2 or more severe acute genitourinary toxicities. The score for the general urinary domain of the expanded prostate cancer index composite quality-of-life scores dropped significantly at 1 month after high-dose-rate brachytherapy, and then returned to the baseline level by 3 months. Among the dose–volume histogram parameters, the reduction of the expanded prostate cancer index composite quality-of-life scores for the general urinary domain and its subscales at 12 months after high-dose-rate brachytherapy was significantly greater in the patients for whom the V150 or urethral D10 was within the upper 20% of the range than in those in whom the values of these dosimetric parameters were within the lower 20% of the range.Conclusion
The high-dose area of the prostate gland (V150) or urethra (D10) might influence the quality-of-life scores for the urinary domain and its subscales over the long term.