Late toxicity described using patient reported outcomes measures (PROMS) in men treated with salvage radiation following primary high intensity focal ultrasound (HIFU) for localized prostate cancer.

Abstract

131 Background: In primary treatment of localised prostate cancer, minimally invasive ablative therapies such as HIFU aim to achieve cancer control whilst offering a potentially favourable toxicity profile. At 5 years median follow up, 12% of patients treated with focal HIFU require salvage therapy. PROMS using Expanded Prostate Cancer Index Composite for Clinical Practice (EPIC‐CP) provide a validated and clinically relevant tool to assess and quantify side effects from pelvic radiotherapy. There is limited data on late toxicity using PROMs with salvage radiotherapy in this setting. Methods: Retrospective analysis from prospectively collected data of 28 patients who received salvage radiotherapy at our institution 2010-2018 was performed. Late bowel and urinary toxicity measured by EPIC-CP is reported. Results: Gleason score at diagnosis: 3+3 4/28; 3+4 22/28; 4+3 2/28. HIFU treatment received: focal: 9/28; whole gland: 6/28; focal and redo focal: 7/28; focal and redo whole gland: 1/28; whole gland and redo: 5/28. All patients had mpMRI and biopsy proven recurrence with median PSA 6.6 ng/ml (0.57- 30.89). Median age at radiation was 67 years (55-80). Patients received 74 Gy to the prostate and 4 patients received additional pelvic lymph node irradiation. Three men received conformal radiotherapy (multiphase technique) and 25 arcing intensity modulated radiotherapy with hormone therapy as per risk stratification. Cumulative incidence of toxicity is reported at median follow-up of 43 months (7-99). Overall urinary function: no problem 8/28; very small problem 4/28; small problem 7/28; moderate problem 5/28; big problem 4/28 Urinary Incontinence Symptom Score: 2.5/12 (0-12) Urinary Irritation /Obstructive Symptom Score: 3.1/12 (0-12) Bowel Symptom Score: 3.5/12 (0-11) Biochemical relapse has occurred in 2/28 patients. Conclusions: Functional and oncological outcomes for a greater number of patients treated with minimally invasive ablative therapies followed by salvage radiation are required, however this data suggests radiation is a well-tolerated and effective salvage option following primary HIFU.