Work

Dosimetric evaluation and clinical application of collimated apertures with proton beam line scanning in stereotactic radiotherapy

Year: 2025

Type: article

Abstract: Purpose Stereotactic radiotherapy (SRT) is a highly effective treatment with precision for small, localized lesions. Proton therapy, characterized by the Bragg peak, offers superior dose conformity compared to photon‐based approaches. However, challenges remain in minimizing lateral penumbra and optimizing dose delivery, particularly for small targets. This study presents the first clinical application of collimated apertures integrated with the proton line scanning technique for proton stereotactic radiotherapy (PSRT). The aim was to evaluate the dosimetric advantages and clinical feasibility of this innovative approach. Methods Over a 1‐year period, 30 patients with small lesions, including choroid melanoma and arteriovenous malformations, were treated using proton line scanning. Two planning strategies were evaluated: uncollimated proton line scanning (UPLS) and collimated proton line scanning (CPLS), incorporating patient‐specific apertures. Dosimetric comparisons were conducted using the Homogeneity Index (HI), Paddick Conformity Index (CI Paddick ), Gradient Index (GI), and R50%. Treatment accuracy was validated using absolute dose measurements and Gamma Passing Rate (GPR) analysis under the criteria of 3%/3 and 2%/2 mm. Results Plans incorporating customized collimated apertures showed significant improvements in dose conformity, with higher CI Paddick values ( p < 0.001), and exhibited steeper dose fall‐off, as reflected in lower GI and R50% values ( p < 0.001). A trend toward more homogeneous dose distributions was also observed ( p < 0.001). GPR analysis confirmed high treatment accuracy, with an average value of 99.00 ± 1.83% (3%/3 mm) and 91.06 ± 4.91% (2%/2 mm). Conclusions Integrating customized collimated apertures with proton beam line scanning is clinically feasible, improving precision, dose conformity, and healthy tissue sparing in PSRT. These findings support adopting this novel approach to advance precision proton therapy for small lesions.

Source: Journal of Applied Clinical Medical Physics

DOI: 10.1002/acm2.70128

Authors: Chen‐Yu Chou, Hsiao‐Chieh Huang, Shen‐Hao Lee, Shih‐Ming Hsu

Institutions: National Yang Ming Chiao Tung University, Linkou Chang Gung Memorial Hospital

Language: English

Topic: Radiation Therapy and Dosimetry

Subfield: Pulmonary and Respiratory Medicine

Field: Medicine

Domain: Health Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $900