Adaptive Radiation Therapy for Gynecologic Cancers

Important in the implementation of ART for gynecologic cancers is a standard delineation of the target volumes, both in the postoperative and in the intact pelvis. The standard target volumes for pelvic irradiation in postoperative gynecologic malignancies include the parametrium, the upper vagina and vaginal cuff, and the pelvic lymph nodes. Traditional radiation techniques utilized to treat the pelvis consisted of either two (anteroposterior- posteroanterior [AP-PA]) or four (AP-PA, right and left laterals) fields. Historically, these fields were designed utilizing plain radiographs and bony landmarks for borders based on anatomical knowledge obtained during surgical trials (Greer et al. 1990). Conventionally, the superior field border for gynecologic malignancies has been placed at the level of the L4-L5 or L5-S1 interspace. If iliac or para-aortic nodal involvement was identified, the border was extended superiorly for additional coverage.