Spatially fractionated proton therapy (SFPT) for bulky tumors: A preliminary clinical exploration
10.3760/cma.j.cn112271-20250313-00087
- VernacularTitle:巨块型肿瘤质子空间分割放射治疗临床初步探索
- Author:
Lei LIU
1
;
Tao MA
;
Xiaoming LU
;
Hongyan ZHANG
;
Tao ZHOU
;
Shuanghu YUAN
Author Information
1. 中国科学技术大学附属第一医院离子医学中心（合肥离子医学中心）放疗科，合肥 230088
- Publication Type:Journal Article
- Keywords:
Proton therapy;
Spatially fractionated radiation therapy(SFRT);
Bulky tumor
- From:
Chinese Journal of Radiological Medicine and Protection
2025;45(9):863-869
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To report the preliminary clinical exploration result of spatially fractionated radiation therapy (SFPT) using the pencil-beam-scanning (PBS) technique at a single center for the treatment of patients with bulky tumors.Methods:Data on the clinical characteristics, tumor characteristics, and dosimetric parameters were retrospectively collected from patients with bulky tumors at the Radiation Oncology Department, Ion Medical Center, First Affiliated Hospital of University of Science and Technology of China (i.e., the Hefei Ion Medical Center) from April 2024 to December 2024. Three-dimensional lattice radiotherapy (LRT) was primarily utilized in the SFRT, with multi-field robust optimization performed using pencil beam scanning. SFRT target volumes (STVs) were defined as 1.0 cm-diameter spheres. Primary observation indicators included the remission rate of tumor-associated symptoms, followed by the local tumor control rate.Results:A total of 12 patients were enrolled in this study, with a median age of 61 years (28-85 years). The primary tumors included hepatocellular carcinoma (six patients), sarcomas (three patients), and lung cancer (two patients). Eight patients received concurrent systemic therapy. The SFRT plans showed a median gross tumor volume (GTV) of 429.63 cm 3 (120.60-2 053.30 cm 3), a median STV number of 8 (3-20), a single-fraction dose to STVs of 10 GyE, a median irradiation quantity of 6 (3-8), a median STV of 8 cm 3 (3-20 cm 3), a median STV proportion of 2.09% (0.62%-3.30%), a median GTV corresponding to a single STV of 52.91 cm 3 (30.25-159.82 cm 3), and a median peak-to-valley dose ratio of 3.37 (2.29-7.60). All patients received conventionally fractionated proton therapy (CFPT), with a median prescription dose of 50 GyE (40-60 GyE). Furthermore, these patients showed a median follow-up time of 174 d (133-235 d), a remission rate of tumor-associated symptoms of 75%, and a local control rate of 100%. Four patients experienced grade 1-2 treatment-related adverse events, suggesting high overall tolerability of the patients. Conclusions:SFRT represents a promising technique with high control rates and tolerability for bulky tumors, providing the possibility for quick symptom relief and the control of tumor progression.
