Genitourinary Cancer

PV QA 1 - Poster Viewing Q&A 1

SU_20_2287 - A Phase II trial of low dose rate brachytherapy combined with ultra-hypofractionated, image-guided, intensity-modulated radiation therapy for clinically localized, intermediate risk prostate cancer: a preliminary analysis

Sunday, October 21
1:15 PM - 2:45 PM
Location: Innovation Hub, Exhibit Hall 3

A Phase II trial of low dose rate brachytherapy combined with ultra-hypofractionated, image-guided, intensity-modulated radiation therapy for clinically localized, intermediate risk prostate cancer: a preliminary analysis
M. A. Kollmeier1, S. McBride1, S. Lochansingh1, M. Varghese1, D. Debonis1, G. Cohen2, A. L. Damato3, and M. J. Zelefsky1; 1Memorial Sloan Kettering Cancer Center, New York, NY, 2MSKCC, NY, NY, 3Brigham & Women's Hospital/Dana-Farber Cancer Institute, Boston, MA

Purpose/Objective(s): To report early toxicity results of combination of brachytherapy and ultra-hypofractionated radiation therapy in a Phase II prospective trial

Materials/Methods: 46 patients with intermediate risk prostate cancer underwent LDR prostate brachytherapy using Pd-103 (100Gy) followed by ultra-hypofractionated, image-guided intensity modulated radiation therapy to a dose of 25Gy in 5 fractions delivered every other day. Eligibility included: clinical stage T2b/c or Gleason 7 or PSA 10-20ng/mL, prostate volume ≤ 60cc, and an IPSS ≤ 15. Patients were followed at 1, 3 and 6 months then every 6 months for two years. Post-treatment assessments include PSA, CTCAE 4.0 treatment-related toxicities, and patient-reported outcomes including IPSS. The primary endpoint of the study was was urinary toxicity at 12 months, which all patients have reached. A post-treatment biopsy was planned between 24-36 months. The trial was initiated in 11/2014 and completed accrual in 03/2017. We report acute toxicities in the first 24 patients who have reached 24 months of follow-up.

Results: 15/24 (63%) patients experienced acute grade 2 urinary toxicity which primarily consisted of urinary frequency, urgency and/or weak stream requiring medication. All were resolved at last followup except 1 patient with urinary frequency at time of this analysis. The average IPSS at baseline was 5.29 which peaked at 1m (average 13.9) and subsequently declined to an average of 9.7 at 12months and 5.4 at 24 months. In terms of rectal toxicity, 2 patients experienced grade 2 proctitis and rectal hemorrhage and 1 patient experienced a 3 grade toxicity (rectal ulcer), all of which were resolved with conservative management. The 12 and 24 month post-treatment PSA median nadirs were 0.57ng/mL and 0.25ng/mL, respectively. 14 patients had post-treatment surveillance biopsies, 13 of which were negative; one equivocal biopsy demonstrated adenocarcinoma with treatment effects.

Conclusion: In this preliminary analysis of a prospective trial of LDR brachytherapy combined with hypofractionated IGRT, we demonstrate acceptable acute urinary and rectal toxicity. Post-treatment biopsies at 24-36m have been negative to date. Additional followup is needed to confirm these findings.

Author Disclosure: M.A. Kollmeier: None. S. McBride: None. M. Varghese: None. G. Cohen: None. M.J. Zelefsky: Consultant; Consultant.

Send Email for Marisa Kollmeier


Assets

SU_20_2287 - A Phase II trial of low dose rate brachytherapy combined with ultra-hypofractionated, image-guided, intensity-modulated radiation therapy for clinically localized, intermediate risk prostate cancer: a preliminary analysis



Attendees who have favorited this

Please enter your access key

The asset you are trying to access is locked. Please enter your access key to unlock.

Send Email for A Phase II trial of low dose rate brachytherapy combined with ultra-hypofractionated, image-guided, intensity-modulated radiation therapy for clinically localized, intermediate risk prostate cancer: a preliminary analysis