Dosimetric impact of edema on inguinal lymph node boost in locally advanced vulvar cancer

Authors Sandy Mohamed, Lars Fokdal, Marianne S Assenholt, Jesper Kallehauge, Jacob C Lindegaard, Kari Tanderup
Source J Appl Clin Med Phys. 2021 Oct;22(10):315-319 Publicationdate 25 Aug 2021
Abstract

Abstract

We aimed to evaluate the extent of groin edema and its dosimetric effect in boosted inguinal lymph nodes (LN) for vulvar cancer patients. The level of edema was determined in 10 patients treated with radical radiotherapy. A dosimetric evaluation of six LNs in the patient with the maximum level of edema was performed. The accumulated dose across CBCT fractions was acceptable for all six LNs (>94% of prescribed dose) even with the development of up to 13 mm of edema. The major contributor to fractional dose degradation was geographical displacement of the nodes. We suggest evaluation of edema on daily CBCT.

Keywords: VMAT; cancer vulva; daily CBCT; groin edema; image guided radiotherapy; inguinal lymph node boost.