Dosimetric evaluation of field parameters in VMAT for cervical cancer with inguinal lymphatic drainage extension.

ABSTRACT: For cervical cancer radiotherapy, patients requiring inguinal lymphatic drainage (ILD) extension fields pose challenges due to the large and complex target volume. To investigate the dosimetric effects of x-jaw width, jaw aperture position, and the number of arcs on volumetric modulated arc therapy (VMAT) plans for ILD extension fields, in order to optimize treatment planning. Thirty-nine patients were retrospectively included, and seven VMAT planning groups were created: OF (open field), X = 15/16/17/18 (jaw widths of 15-18 cm), SP (split-field, four arcs), and X = 15 M (jaw aperture moved toward the isocenter). Dosimetric parameters, including homogeneity index (HI), target coverage, and organs-at-risk (OARs) doses, were compared. The X = 15 plan achieved significantly lower intestinal, bladder, and rectal doses compared to the X = 17 and X = 18 plans (p < 0.05). The SP plan demonstrated superior HI and OARs sparing compared to the X = 15 plan, but required longer treatment times. The X = 15 M plan resulted in reduced edge doses but increased intestinal and bladder doses. For cervical cancer ILD extension fields, dual-arc VMAT plans with a 15 cm jaw width (X = 15) are recommended for optimal balance between target coverage and OARs sparing. Split-field plans may be considered if extended treatment time is acceptable.

SUBMITTER: Zeng J 

PROVIDER: S-EPMC12276232 | biostudies-literature | 2025 Jul

REPOSITORIES: biostudies-literature