192 The 10-years follow-up of the ARO 96-02/AUO AP 09/95 trial on adjuvant radiotherapy (ART) versus wait-and-see (WS) after prostatectomy for pT3 cancer – subgroup analysis

Moderate hypofractionated post-prostatectomy radiation therapy is feasible and well tolerated: experience from a single tertiary cancer centre

PURPOSE

Conventional post-prostatectomy radiation therapy comprises 6.5-8 weeks of treatment, therefore, hypofractionated and shortened schemes arouse increasing interest. We describe our experience regarding feasibility and clinical outcome of a post-prostatectomy moderate hypofractionated image-guided radiotherapy schedule MATERIALS AND METHODS: From Oct 2015-Mar 2020, 113 patients, median age of 62 years-old (range 45-76) and prostate adenocarcinoma of low risk (30%), intermediate risk (49%) and high risk (21%) were included for adjuvant (34%) or salvage radiation therapy (66%) after radical prostatectomy (RP). All patients underwent radiotherapy with image-guided IMRT/VMAT to a total dose of 62.5 Gy in 2.5 Gy/fraction in 25 fractions. Sixteen patients (14%) received concomitant androgen deprivation therapy.

RESULTS

With a median follow-up of 29 months (range 3-60 months) all patients but three are alive. Eleven patients (10%) developed exclusive biochemical relapse while 19 patients (17%) presented macroscopically visible relapse: prostatectomy bed in two patients (2%), pelvic lymph nodes in 13 patients (11.5%) and distant metastases in four patients (4%). The 3 years actuarial rates for OS, bFRS, and DMFS were 99.1, 91.1 and 91.2%, respectively. Acute and late tolerance was satisfactory. Maximal acute genitourinary (AGU) toxicity was G2 in 8% of patients; maximal acute gastrointestinal (AGI) toxicity was G2 in 3.5% of patients; maximal late genitourinary (LGU) toxicity was G3 in 1% of patients and maximal late gastrointestinal (LGI) toxicity was G2 in 2% of patients. There were no cases of severe acute or late toxicity. No relationship was found between acute or late GI/GU adverse effects and dosimetric parameters, age, presence of comorbidities or concomitant treatments.

CONCLUSIONS

Hypofractionated radiotherapy (62.5 Gy in 25 2.5 Gy fractions) is feasible and well tolerated with low complication rates allowing for a moderate dose-escalation that offers encouraging clinical results for biochemical control and survival in patients with prostate cancer after radical prostatectomy.