Sahoo, Narayan

Proton therapy is an expanding radiotherapy modality in the United States and worldwide. With the number of proton therapy centers treating patients increasing, so does the need for consistent, high‐quality clinical commissioning practices. Clinical commissioning encompasses the entire proton therapy system's multiple components, including the treatment delivery system, the patient positioning system, and the image‐guided radiotherapy components. Also included in the commissioning process are the x‐ray computed tomography scanner calibration for proton stopping power, the radiotherapy treatment planning system, and corresponding portions of the treatment management system. This commissioning report focuses exclusively on intensity‐modulated scanning systems, presenting details of how to perform the commissioning of the proton therapy and ancillary systems, including the required proton beam measurements, treatment planning system dose modeling, and the equipment needed.

Proton minibeam therapy (PMBT) is a form of spatially fractionated radiotherapy wherein broad beam radiation is replaced with segmented minibeams—either parallel, planar minibeam arrays generated by a multislit collimator or scanned pencil beams that converge laterally at depth to create a uniform dose layer at the tumor. By doing so, the spatial pattern of entrance dose is considerably modified while still maintaining tumor dose and efficacy. Recent studies using computational modeling, phantom experiments, in vitro and in vivo preclinical models, and early clinical feasibility assessments suggest that unique physical and biological attributes of PMBT can be exploited for future clinical benefit. We outline some of the guiding principle of PMBT in this concise overview of this emerging area of preclinical and clinical research inquiry.

Abstract Existing systems for proton beam dosimetry are limited in their ability to provide a complete, accurate, and detailed account of volumetric dose distribution. In this work, we describe the design and development of a portable, fast, and reusable liquid scintillator-based three-dimensional (3D) optical detection system for use in proton therapy. Our long-term goal is to use this system clinically for beam characterization, dosimetry, and quality assurance studies of discrete spot scanning proton beam systems. The system used a 20 × 20 × 20 cm 3 liquid scintillator volume. Three mutually orthogonal cameras surrounding this volume captured scintillation photons emitted in response to the proton beams. The cameras exhibited a mean spatial resolution of 0.21 mm over the complete detection volume and a temporal resolution of 11 ms. The system is shown to be capable of capturing all 94 beam energies delivered by a synchrotron and performing rapid beam range measurements with a mean accuracy of 0.073 ± 0.030 mm over all energies. The range measurement uncertainty for doses less than 1 cGy was found to be ±0.355 mm, indicating high precision for low dose detection. Finally, we demonstrated that using multiple cameras allowed for the precise locations of the delivered beams to be tracked in 3D. We conclude that this detector is capable of real-time and accurate tracking of dynamic spot beam deliveries in 3D. The high-resolution light profiles it generates will be useful for future 3D construction of dose maps.