Can volumetric arc therapy be an alternative to brachytherapy in advanced cervical cancer radiotherapy?

The preferred treatment for locally advanced cervical cancer, classified as IB2-IVA in Federation of Gynaecology and Obstetrics staging, has been external radiotherapy to the pelvis, cervix, uterus, and parametrium, combined with an additional dose of intracavitary brachytherapy (BRT). Occasionally, the treatment team may encounter patients who refuse treatment, large cervical tumours with extensive lateral parametrial involvement that are inaccessible for interstitial implant, or medical conditions that completely prevent the use of BRT. These challenging situations call for an alternative approach to deliver the intended therapeutic dose without adhering strictly to the belief that BRT is indispensable. This study aims to evaluate the feasibility of volumetric modulated arc therapy (VMAT) as a substitute for BRT by comparing 3D BRT and VMAT-generated stereotactic body radiotherapy (SBRT) plans, particularly for patients with advanced cervical cancer and large tumour sizes. Based on dosimetric data, SBRT may be a viable alternative to BRT if necessary.