Impact On Patient Reported Quality of Life From Reducing Prostate Margins in Patients Who Underwent Radiotherapy: A Prospective Clinical Trial
A Kumarasiri*, S Brown, M Elshaikh, I Chetty, B Movsas, Henry Ford Health System, Detroit, MI
Presentations
PO-GePV-T-64 (Sunday, 7/25/2021) [Eastern Time (GMT-4)]
Purpose: To investigate the impact of reducing planning target volume (PTV) margins on patient reported quality-of-life (QOL) for patients with localized prostate cancer after radiation therapy (RT)
Methods: A cohort of 20 patients were included in a single institution IRB-approved prospective study, out of which 9 were planned with reduced margins (5 mm uniformly except 4 mm at prostate/rectum boundary), while 11 were control patients with standard margins (10/6 mm). At time points pre-treatment, post-treatment, and at 2, 6, 12, 18, 24, 36, 48, and 60 months follow-ups, EPIC-26 based patient reported QOL data was collected. Validated EPIC-26 methodology was used to baseline correct and standardize all post-RT QOL scores to five separate EPIC QOL domains on a [0-100] scale. Correlations between QOL scores and dosimetric parameters were investigated, and the overall QOL differences between the two groups (QOL(M-R)-QOL(control)) were calculated for each time point.
Results: Age, Gleason score, and PSA level differences between the two groups were statistically insignificant (p>0.2). Median QOL follow-up length for the 20 patients was 48 months at the time of reporting. At 48 months post-RT, standardized and baseline-corrected mean QOL(M-R)-QOL(control) were improved for “Urinary Incontinence”, “Urinary Irritative/Obstructive”, “Bowel”, and “Sexual” EPIC domains by 3.5,14.8,10.2, and 16.1, respectively. QOL differences between groups were clinically significant for the last 3 domains, while statistically significant for only “Urinary Irritative/Obstructive” domain (p=0.03). PTV/rectum (p=0.03) and PTV/bladder (p=0.14) intersection volumes were larger for the control group (7.2±5.8, 18.2±8.1 cc) compared with the margin-reduced group (2.6±1.8, 12.5±8.3 cc), while the dose to these intersection volumes did not reach statistical significance (p>0.1) between the groups. PTV/rectum intersection volume showed a moderate correlation (R=-0.6, p=0.01) to “Bowel” EPIC domain.
Conclusion: Margin-reduced group exhibits clinically meaningful improvement in Urinary, Bowel, and Sexual QOL domains. More patients are needed to draw unequivocal conclusions.
ePosters
Keywords
Quality Of Life, Toxicity, Dose Response
Taxonomy
TH- Response Assessment: General (most aspects)
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