VMAT in Prostate Cancer: Experience at the RABAT INO national Oncology Institute

Study object : To report the experience of the external radiotherapy department of the RABAT National Institute of Oncology in the conformal irradiation of prostate cancers with intensity modulation of the volumetric modulated arc therapy (VMAT). Materials and methods: This is a retrospective study conducted in the external radiotherapy department between January 2017 and December 2021. All patients with prostate cancer were included. Those with immediate metastatic disease at the time of diagnosis were excluded. For 441 patients, respecting dose constraints in organs at risk of toxicity. VMAT was the technique used in all our patients. Results and statistical analysis: A total of 441 prostate cancer patients were treated in our department. The median age at diagnosis was 72 years, with an average consultation time of 8 months. Mean PSA: 59 ng/ml (range 5.03 to 403 ng/ml). Pelvic MRI was performed in 94% of patients. Three of our patients were classified as oligo-metastatic. The predominant histological type was ADK in 100% of cases. Tumors were classified according to the current Amico and NCCN classifications. Treatment consisted of a combination of external radiotherapy and hormone therapy in 97% of cases, and exclusive radiotherapy in 3% of cases. In terms of therapeutic tolerance, 66% of patients experienced acute toxicities of all kinds, and 45% of patients experienced late toxicities. Complete remission was achieved in 100% of patients, with a mean PSA Nadir of 0.09 ng/ml. Overall recurrence-free survival was 94%, with a relapse rate of 6%. Conclusion : VMAT is an effective technique for treating prostate cancer, with a better rate of locoregional control and reduced toxicity than 3D conformal radiotherapy.