Bowel and urinary quality of life after whole-pelvic versus prostate-only volumetric-modulated arc therapy for localized prostate cancer.

PURPOSE: This study aimed to compare bowel and urinary health-related quality of life (HRQOL) between prostate-only (PO) volumetric modulated arc therapy (VMAT) and whole-pelvis (WP) VMAT in patients with localized prostate cancer. METHODS AND MATERIALS: A total of 234 patients treated with definitive VMAT to 78 Gy in 39 fractions were enrolled. Of these, 108 patients received PO-VMAT and 126 patients received initial WP-VMAT to 46.8 Gy in 26 fractions using a simultaneous integrated boost technique. HRQOL was prospectively assessed before radiation therapy (baseline), and 3, 6, 12, and 24 months after treatment using the Expanded Prostate Cancer Index Composite (EPIC). RESULTS: Baseline HRQOL scores did not differ significantly between the 2 groups. No significant between-group differences in HRQOL change from baseline were observed for all bowel and urinary EPIC domains. The proportion of patients showing a clinically relevant decrease in bowel and urinary HRQOL scores from baseline was similar between the groups throughout the follow-up period. An analysis of individual HRQOL items showed that patients undergoing WP-VMAT were more likely to report moderate/big problems with bloody stools (P = .039) and overall bowel problems (P = .008) than those undergoing PO-VMAT at 12 months. There was no significant between-group difference in any individual items at 24 months, however. CONCLUSIONS: Bowel and urinary HRQOL is largely similar for patients receiving PO-VMAT and WP-VMAT during 24 months of follow-up, with the only differences seen in responses to specific bowel HRQOL items at 12 months.

Optimal bladder volume at treatment planning for prostate cancer patients receiving volumetric modulated arc therapy.

PURPOSE: To investigate optimal bladder volumes at treatment planning (TP) in prostate cancer patients who undergo volumetric modulated arc therapy (VMAT). METHODS AND MATERIALS: To determine the minimum value, 122 patients were classified into 6 groups according to the bladder volume at TP: <100 mL (group 1), 100-149 mL (group 2), 150-199 mL (group 3), 200-249 mL (group 4), 250-299 mL (group 5), and ≥300 mL (group 6). Bladder volumes receiving more than 70 Gy (V70Gy) and V50Gy were calculated in each subgroup and compared with the bladder dose-volume constraints specified in our institution. To determine the maximum value, 64 patients who underwent uniform nursing interventions were classified into the same 6 groups. Bladder volumes on cone beam computed tomography (CBCT) images were measured once weekly during treatment, for a total of 8 measurements. Relative bladder volumes (bladder volume on CBCT image [mL]/bladder volume at TP [mL] × 100%) were evaluated in each of the 6 subgroups. RESULTS: The upper bounds of the 95% confidence intervals of the mean V70Gy and V50Gy values in group 1 exceeded the dose constraints at our institution. The mean relative bladder volumes were 104%, 91%, 77%, 81%, 63%, and 59% in groups 1, 2, 3, 4, 5, and 6, respectively. The institutional criterion of 70% for the mean relative bladder volume was achieved in groups 1-4, but it could not be achieved in groups 5-6. Therefore, the patients in groups 2-4 met both institutional dose constraints for the bladder at TP and the institutional criterion for the mean relative bladder volume during treatment. CONCLUSIONS: The optimal bladder volumes at TP were between 100 and 250 mL in this setting. Nursing intervention needs to be implemented before treatment planning to ensure that patients achieve the optimal bladder volume range.