ESTRO 2024 - Abstract Book

S2552

Clinical - Urology

ESTRO 2024

Urinary and bowel QoL was assessed prospectively using the Expanded Prostate Cancer Index Composite Short Form (EPIC-26) at baseline, on the last day and 12 months after treatment. The multi-item scale scores were converted to a scale of 0 to 100, with higher scores indicating better QoL.

The other data analyzed, including the toxicities, were collected retrospectively by reviewing the clinical records.

Toxicities were classified according to the National Cancer Institute’s Common Terminology Criteria (CTCAE) version 5.0.

Statistical analysis was performed using IBM SPSS Statistics version 27 software. Differences between groups were analyzed using independent samples t-test, Mann-Whitney U- test and Fischer’s exact test as appropriate. Friedman’s Two -Way ANOVA by Rank was applied to determine longitudinal changes in QoL for each group individually. Values of p<0.05 were considered significant.

Results:

The baseline characteristics of the HA spacer patients were similar to those of the balloon spacer patients, including age at treatment, clinical stage, Gleason score, percentage of positive biopsy cores, pretreatment PSA, prostate volume, concomitant hormone therapy and the interval between spacer placement and start of treatment.

The median perirectal distance was significantly higher in balloon spacer patients (1.99cm vs. 1.63cm, p=0.038).

When comparing the QoL before and on the last day of treatment, no significant differences were found in urinary function between the two groups (p=0.059). The balloon spacer group showed a greater median decrease in the urinary function score (-13.9 vs. 0) and irritative/obstructive symptoms (-18.8 vs. 0) in comparison to the HA spacer group. Additionally, when comparing QoL on the last day and 12 months post-treatment, no significant differences were identified in urinary function between the two groups (p=0.879). The balloon spacer group showed a greater median increase in the urinary function score (+17 vs. +4) and obstructive/irritative symptoms (+12.8 vs. +9.3). Both HA (p=0.008) and balloon spacer patients (p=0.049) reported changes in irritative/obstructive symptoms during the longitudinal QoL assessment. The median scores for patients with HA spacers in this category were 90.6 before, 81.3 on the last day, and 100 at 12 months after treatment. Balloon patients had median scores of 87.5 before, 62.5 on the last day, and 81 at 12 months after treatment. No significant longitudinal differences in overall urinary function or incontinence were observed between the two groups when assessed independently. Regarding intestinal function, there were significant longitudinal differences only for the balloon spacer group (p=0.018). Nonetheless, the median score in this category was 100 at all three analyzed moments. There were also no significant differences in intestinal function between the two groups (p>0.05).

The most common acute adverse events were dysuria (n=6), polyuria (n=3) and urinary tract infection (n=3) in the HA spacer patients, and dysuria (n=6), perineal pain (n=4) and polyuria (n=3) in the balloon spacer patients.

Five patients with the balloon spacer experienced grade 1 late urinary toxicity, while no patient with the HA spacer experienced this type of toxicity (p=0.042).