Acute Toxicity in Moderate Hypofractionation Over Three Weeks for Localized Prostate Cancer Without Marker Implantation

Abstract

Listen

Translate article

Purpose: prospective observational study of patients with localized prostate cancer referred for radiotherapy using a hypofractionation scheme without marker implantation with the advantages offered by shorter treatments in lower-middle-income countries. Our objective was to establish the acute genitourinary and gastrointestinal toxicity using hypofractionation radiotherapy scheme of 15 fractions. Methods and Materials: From March to November 2022, patients with low- to intermediate-risk prostate cancer received 54 Gy in 15 fractions (3.6 Gy per fraction) for 3 weeks using VMAT without intraprostatic fiducial markers or a rectal hydrogel spacer. Were evaluated through rectal examination, prostate-specific antigen (PSA) levels, and diagnostic imaging such as computed tomography (CT), magnetic resonance imaging (MRI), bone scan, or positron emission tomography (PET/CT) with PSM, the cumulative incidence of late grade ≥2 genitourinary and gastrointestinal toxicities were analyzed. Results: Thirty-six patients were enrolled in this prospective observational study; all of them were treated with highly hypofractionated VMAT with intermediate to high risk. The follow-up period was 3 months for evaluated acute toxicity. In terms of genitourinary toxicity, 8% of patients experienced grade 2 toxicity, which included urinary frequency, urgency, and dysuria. There were no cases of grade 3 or higher genitourinary toxicity. Regarding gastrointestinal toxicity, 5% of patients experienced grade 2 toxicity, which included diarrhea and rectal bleeding. No grade 3 or higher gastrointestinal toxicity was observed. Conclusions: Highly hypofractionated VMAT delivering 54 Gy in 15 fractions for 3 weeks for prostate cancer without intraprostatic fiducial markers facilitated favorable oncological outcomes without severe complications. These findings support the feasibility and safety of this treatment option and highlight the potential advantages of hypofractionation, further studies are needed to confirm these findings and evaluate the long-term oncological outcomes of moderate hypofractionation for localized prostate cancer.