Work

Interplay Effect in Spot-Scanning Proton Therapy with Rescanning, Breath Holding, and Gating: A Phantom Study

Year: 2024

Type: article

Abstract: The interplay effect is a challenge when using proton scanning beams for the treatment of thoracic and abdominal cancers. The aim of this study was to evaluate the facility-specific interplay effect in terms of dose distortion and irradiation time for different beam delivery modalities, including free breathing (FB) irradiation, rescanning, deep inspiration breath-hold (DIBH), and respiratory gating. This study was carried out at a synchrotron-based facility with spot-scanning beam delivery. A motion phantom with a radiochromic film was used to measure dose distributions. Regular and irregular motion patterns were studied. Dose homogeneity and the gamma index were calculated to quantify the interplay effect. The interplay effect significantly decreased the homogeneity and gamma passing rate by 12% and 46%, respectively, when FB irradiation without motion mitigation was used for 20 mm peak-to-peak motion. Rescanning and DIBH partially mitigated the distortions but doubled the irradiation time, while gating provided the superior dose distribution with only a 25% increase in time compared to FB irradiation without mitigation. The interplay effect was a function of motion amplitude and varied with the beam delivery modality. Gating may be a more preferable technique for the synchrotron-based facility in terms of minimizing dose distortion and treatment time.

Source: Applied Sciences

DOI: 10.3390/app14188473

Authors: Mikhail Belikhin, Alexander Shemyakov, Dmitry Ivanov, Irina Zavestovskaya

Institutions: P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Kurchatov Institute

Language: English

Topic: Advanced Radiotherapy Techniques

Subfield: Radiation

Field: Physics and Astronomy

Domain: Physical Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,728