ESTRO 2024 - Abstract Book

S2624

Clinical - Urology

ESTRO 2024

To evaluate prostate cancer specific domains of health related quality of life after dose escalated ultra-hypo fractionated RT.

Material/Methods:

The Sheba IRB approved database prospectively registers patients treated for prostate cancer and solicits completion of the Expanded prostate cancer index (EPIC) quality of life survey. The database was screened for patients who received dose escalated ultra-fractionated RT to a dose of at least 40 Gy in 5 fractions with at least 12 months of follow-up. Patients with positive nodes or seminal vesicle involvement were excluded and received moderate hypofractionation. Prior to RT all patients had fiducial marker and endorectal spacer (SpacerOAR implantation). All patients underwent CT and MR simulation. The CTV was the prostate and proximal seminal vessels. The PTV was a 0.5 cm expansion of the CTV. The prescription was 40 GY in 8 Gy fractions to the PTV. The urethral dose was de-escalated to 6.5 Gy per fraction if the tumor was not abutting and limited to 7.25 Gy per fraction for abutting tumors. Patients with well-defined tumors received an integrated boost to the GTV of 9 Gy per fraction. The pelvic lymph nodes were treated prophylactically in patients unfavorable intermediate or high risk NCCN category to 25 GY in 5 fractions. Descriptive statistics were generated on STATA 13.1. The 99% Confidence interval and a paired t-test were used to compare EPIC mean scores for multiple comparison with a p value of less than 0.01 indicative of significance. To determine the clinical significance of the difference of mean quality of life scores the minimally important difference of half a standard deviation was used.

Results:

214 patients who received at least 40 Gy were identified. Mean age was 70 +-6.1 Gleason grade 1,2,3,4 and 5 were 6,104,55,20 and 11 patients, respectively. 82 patients received radiotherapy to the pelvic nodes. 35 patients received an integrated boost to the GTV. 155 patients (72.4%) completed both pre-treatment and post-treatment surveys. 3 patients had died before the second survey, 18 patients with disease progression refused the post treatment survey, 13 patients spoke only Russian and 25 patients refused any survey. The median time of the second survey was 28 months +-11 months after radiotherapy (range 12-60 months).

The mean pretreatment and post treatment quality of life domains for the domains of urinary incontinence, urinary obstruction, sexual function, bowel score and hormone/vitality are reported in table 1.

In general, long term quality of life outcomes of dose escalated SBRT were excellent. Compared to before treatment long term post treatment EPIC scores were the same with a trend to improvement for the urinary obstruction domain, stable for the hormonal/vitality and sexual function scale, and marginally less for the bowel and urinary incontinence domains.