Radiotherapy is one of the main treatments in the multidisciplinary management of prostate cancer, both in the early and metastatic stages. Technological evolution has allowed the development of increasingly effective and safe radiant treatments, thanks to the use of imaging techniques (Image guided radiotherapy or IGRT) and real time tracking that allow the safe delivery of high doses with savings in healthy tissues. Moderate (2.3-3 Gy per session) and extreme (>5 Gy per session) hypofractionation patterns have now entered clinical practice. Stereotactic body radiation therapy (SBRT) allows the delivery of ablative doses in 3-5 sessions, promoting the radiobiological response of prostate tissue, more sensitive to dose fractionation as per recent studies.

ONE-SHOT trial: stereotactic radiotherapy in a single session for prostate adenocarcinoma at low and intermediate risk.

At the Radiotherapy and Radiosurgery Unit of Humanitas, directed by Professor Marta Scorsetti, an international study of stereotactic radiotherapy in a single session for localized prostate cancer, the ONE-SHOT trial, is active.

This is a phase I/II study aimed at demonstrating the efficacy and safety of a 19 Gy single session SBRT (stereotactic radiotherapy) approach with urethra savings in low and intermediate risk prostate adenocarcinoma patients. The treatment involves the use of a system similar to GPS, called Calypso©, capable of monitoring in real time the position of the prostate gland thanks to the use of intraprostatic electromagnetic transponders that act as a signal. The study is conducted in collaboration with 3 other Swiss centers (Zurich, Geneva and Chur) and has already completed the enrollment of patients for Phase I, with preliminary results more than satisfactory.

STORM trial: stereotactic radiotherapy in oligometastatic prostate cancer

Stereotactic radiotherapy is also a good treatment for patients with oligometastatic prostate cancer. The efficacy of SBRT for the treatment of lymph node and bone metastases, with local disease control rates above 90%, has already been proven in several studies. In case of diagnosis of pelvic lymph node recurrence, a “metastases-directed” treatment (aimed directly at the treatment of metastasis) can potentially delay the activation of systemic therapy and, in some cases, fully treat the patient. The STORM trial (A Randomized Phase II Trial for the Salvage Treatment of OligoRecurrent Nodal Prostate Cancer Metastases), recently activated in the Radiotherapy and Radiosurgery department of Humanitas, represents an international multicenter study that will explore the difference between conventional radiotherapy treatment on all pelvic lymph nodes and stereotactic radiotherapy targeted only on positive lymph node sites. The study, which has as its promoter center the University Hospital of Ghent (Belgium), provides for the randomized assignment to one of the treatment arms of patients with up to 3 intra-pelvic lymph node metastases from prostate adenocarcinoma, diagnosed by PET-choline or PET-PSMA.