Toxicity Comparison Between Hypofractionated Radiotherapy With HDR Brachytherapy Boost Versus Standard Treatment (HyBraFi)

Toxicity Comparison Between Hypofractionated Radiotherapy With HDR Brachytherapy Boost Versus Standard Treatment

Match Pair Analysis Study, Comparing Toxicities Between 2 Treatment Regiments Including Neo-adjuvant Hormonal Therapy Plus Hypofractionated RT With HDR Brachytherapy Boost Compare to Our Current Clinical Standard Approach at CHU de Quebec

The purpose of this study is to compare toxicities between 2 external beam radiation fractionation schemes plus a brachytherapy boost for prostate cancer. Our current standard use a 2 Gy per fraction schedule which is compare to the experimental hypofractionated 3 Gy per day approach with neo adjuvant hormonal therapy. It will demonstrate the feasibility and safety of such a treatment regimen in prostate cancer. It may also set base for a larger randomized trial.

30 patients with intermediate / extensive low risk (all core biopsies involvements > 50%) prostate cancer (not necessitating to treat the nodal regions) will be included in this study. Patient stage T1 - T2, Gleason score ≤ 7, prostate-specific antigen (PSA) ≤ 20 will be considered. Fiducial gold markers will be introduced in the prostate 1-week before the CT planning. 36 gray (Gy) in 12 fractions using intensity-modulated radiation therapy (IMRT) will be administered to the prostate (margins of 0,5cm) +/- first centimeter of the seminal vesicles. Brachytherapy boost (15 Gy x 1) dosimetric parameters should respect our current standard (Prostate V100 > 90% and V150 ≤ 40%, V200 ≤ 15%, Urethra V125 ≤ 1 cc, Rectum V75 ≤ 1cc, Bladder V75 ≤ 1cc). Short course (4 months) hormonal therapy (Degarelix) will be administered to the patient based upon recommended litterature11, 12. Genitourinary (GU), GI and Sexual toxicity will be self reported. QOL questionnaires will be given to the patients to be answered. Results will be monitored and compared to our currently used standard fractionation regiment. Follow-up will be scheduled 6 weeks after the implant and every 4 months for the first year, every 6 months for the second year 2 to 5, and on a yearly basis after 5 years. PSA & testosterone tests will be done every 3 months for the first 3 years, every 6 months on years 4 and 5, and yearly thereafter.

Patient reported toxicities related to Hypofraction radiation treatment (3 Gy daily, 5 fractions per week) up to a total of 36 Gy to the prostate (+/- seminal vesicles) plus brachytherapy boost (15 Gy in a single fraction) with 4 months neo-adjuvant firmagon (240 mg given as two subcutaneous injections of 120 mg at a concentration of 40 mg/mL as a starting dose with a maintenance dose of 80 mg given as one subcutaneous injection at a concentration of 20 mg/mL administered every 28 days).

Patient reported toxicities related to the Standard radiation treatment (2 Gy daily, 5 fractions per week) up to a total of 44 Gy to the prostate (+/- seminal vesicles) plus brachytherapy boost (15 Gy in a single fraction) with 4 months neo-adjuvant LHRH agonists.

Patient reported toxicities related to Hypofraction radiation treatment (3 Gy daily, 5 fractions per week) up to a total of 36 Gy to the prostate (+/- seminal vesicles) plus brachytherapy boost (15 Gy in a single fraction) with 4 months neo-adjuvant firmagon (240 mg given as two subcutaneous injections of 120 mg at a concentration of 40 mg/mL as a starting dose with a maintenance dose of 80 mg given as one subcutaneous injection at a concentration of 20 mg/mL administered every 28 days).

Patient reported toxicities related to the Standard radiation treatment (2 Gy daily, 5 fractions per week) up to a total of 44 Gy to the prostate (+/- seminal vesicles) plus brachytherapy boost (15 Gy in a single fraction) with 4 months neo-adjuvant LHRH agonists

Evaluate and compare toxicity changes through follow-up between our study population and a reference group in regards to Median international prostate symptoms scores (IPSS).

Evaluate and compare toxicity changes through follow-up between our study population and a reference group in regards to gastro-intestinal (GI) toxicity score.

Comparison of the patient reported Gastro-intestinal toxicity scores through the follow-up between each treatment group.

Evaluate and compare toxicity changes through follow-up between our study population and a reference group in regards to Sexual toxicity (EPIC or SHIM) score.

Comparison of the patient reported Sexual toxicity (EPIC or SHIM) scores through the follow-up between each treatment group.

Inclusion Criteria: 30 patients intermediate / extensive low risk (all core biopsies involvements > 50%) prostate cancer (not necessitating to treat the nodal regions) Patient stage T1 - T2, Gleason score ≤ 7, PSA ≤ 20 will be considered Exclusion Criteria: patient unfit for biopsy or brachytherapy high or low risk prostate cancer

De Bari B, Daidone A, Alongi F. Is high dose rate brachytherapy reliable and effective treatment for prostate cancer patients? A review of the literature. Crit Rev Oncol Hematol. 2015 Jun;94(3):360-70. doi: 10.1016/j.critrevonc.2015.02.003. Epub 2015 Feb 17.