Planning Strategy to Optimize the Dose-Averaged LET Distribution in Large Pelvic Sarcomas/Chordomas Treated with Carbon-Ion Radiotherapy.

ABSTRACT: To improve outcomes in large sarcomas/chordomas treated with CIRT, there has been recent interest in LET optimization. We evaluated 22 pelvic sarcoma/chordoma patients treated with CIRT [large: HD-CTV ≥ 250 cm³ (n = 9), small: HD-CTV < 250 cm³ (n = 13)], D_RBE|LEM-I = 73.6 (70.4-73.6) Gy (RBE)/16 fractions, using the local effect model-I (LEM-I) optimization and modified-microdosimetric kinetic model (mMKM) recomputation. We observed that to improve high-LETd distribution in large tumors, at least 27 cm³ (low-LETd region) of HD-CTV should receive LETd of ≥33 keV/µm (p < 0.05). Hence, LETd optimization using 'distal patching' was explored in a treatment planning setting (not implemented clinically yet). Distal-patching structures were create

SUBMITTER: Nachankar A 

PROVIDER: S-EPMC10571585 | biostudies-literature | 2023 Oct

REPOSITORIES: biostudies-literature