Prostate cancer (PCa) is one of the most common malignancies in men and remains a major cause of cancer-related death worldwide. Radiotherapy is a well-established treatment modality for PCa, offering clinical outcomes comparable to surgical approaches. In recent years, stereotactic body radiotherapy (SBRT), characterized by the delivery of high radiation doses in a limited number of fractions, has been increasingly adopted as a standard approach in the treatment of prostate cancer, due to its favorable efficacy and toxicity profile. CyberKnife (CK) is one of the most commonly used hypofractionated radiotherapy techniques. This preliminary study aimed to evaluate and compare the radiation dose delivery and treatment time of CK-based SBRT using two different collimation systems: the multileaf collimator (MLC) and the IRIS variable aperture collimator, a dynamic device that adjusts its opening to simulate different circular field sizes. A total of 19 patients with low-to-intermediate-risk PCa were selected and treated at the Radiation Oncology Department of the National Cancer Institute IRCCS Fondazione G. Pascale in Naples between January 2024 and January 2025. For each patient, two treatment plans were generated-one with the IRIS collimator and one with the MLC. The results demonstrated that the use of the MLC significantly reduced treatment time while maintaining dosimetric quality comparable to IRIS-based plans. These findings support the clinical benefit of MLC implementation in prostate SBRT with the CK system.
Bioengineering (Basel, Switzerland). 2026 May 22*** epublish ***
Gaetano Gagliardo, Marcello Serra, Gianluca Ametrano, Rosario Megna, Valentina d'Alesio, Francesca Buonanno, Cecilia Arrichiello, Rossella Di Franco, Valentina Borzillo, Esmeralda Scipilliti, Rocco Mottareale, Simona Mercogliano, Mariagabriella Pugliese, Maria Quarto, Vincenzo Ravo, Paolo Muto
Post Graduate School in Medical Physics, University of Naples Federico II, 80131 Naples, Italy., Department of Radiation Oncology, Istituto Nazionale Tumori-IRCCS-Fondazione G. Pascale, 80131 Naples, Italy., Institute of Biostructure and Bioimaging, National Research Council, 80145 Naples, Italy., Department of Physics "E. Pancini", University of Naples Federico II, 80126 Naples, Italy., Fondazione Muto ETS, 80132 Naples, Italy.