Speaker
Descrizione
Uveal melanoma represents the most common primary intraocular malignancy in adults.
Current treatment strategies include eye-preserving stereotactic radiotherapy (SRT) and
enucleation in advanced-stage disease. In this study, we investigate the feasibility of lowenergy
electron ultra-high dose-rate radiotherapy (eFLASH-RT) as a novel treatment
modality for localized uveal melanoma. The FLASH effect, characterized by reduced toxicity
to normal tissues while maintaining tumor control, may offer substantial advantages in terms
of clinical outcome and ocular preservation.
To this end, a comprehensive Monte Carlo (MC) simulation study was implemented to model
the ElectronFlash (EF) linear accelerator of Centro Pisano Flash RadioTherapy (CPFR) and
to generate patient-specific FLASH-RT treatment plans using both real and synthetic
electron spectra up to 30 MeV. The potential radiobiological sparing effect of FLASH-RT
plans was also considered, introducing the Dose Modifying Factor. Then, a quantitative and
reproducible scoring system, integrating physical and radiobiological metrics derived from
dose–volume histograms, was developed to enable objective comparison among clinically
delivered SRT treatments on real patients and simulated FLASH-RT treatment plans.
Comparative analysis between simulated FLASH-RT plans and clinically delivered SRT
treatments showed comparable target coverage, with PTV homogeneity achieved by
FLASH-RT comparable to that of SRT. However, the results indicate that a FLASH sparing
factor of approximately 45% would be required to achieve a meaningful reduction in normal
tissue exposure.
Overall, these results demonstrate the technical and dosimetric feasibility of electron
FLASH-RT as a potential organ-preserving strategy for uveal melanoma. Moreover, this
study provides a generalizable and reproducible methodology for the evaluation of FLASHRT
treatment plans, including a scoring framework that allows objective comparison between
conventional and FLASH modalities in terms of RBE. Nonetheless, extensive preclinical
studies are necessary to validate the magnitude and consistency of the FLASH effect in
ocular tissues prior to clinical translation.
