Combined pretreatment with F-FDG PET/CT and Comet assay guides the concurrent chemoradiotherapy of locally advanced cervical cancer: study protocol for a randomized controlled trial.

Background: Cisplatin-based chemoradiation is the standard of care for patients with locally advanced cervical cancer. Nevertheless, an increasing number of radio-resistant tumors still recur.

Methods And Design: Three hundred cervical cancer patients with FIGO stages IB2-IVA and no para-aortic lymphadenopathy (> 10 mm) will be enrolled. All patients will be randomly divided into four arms to receive either (1) intensity modulated radiation therapy (IMRT), (2) RapidArc, (3) positron emission tomography/computed tomography (PET/CT) with F-18 fluorodeoxyglucose (FDG), or (4) Comet assay-guided IMRT, PET/CT, and Comet assay-guided RapidArc. All patients will receive definitive radiotherapy consisting of external beam whole pelvic radiation therapy and high-dose rate intracavitary brachytherapy. Cisplatin 30 mg/m weekly will be administered concurrently for five courses. Two to four cycles of TP (Taxol 135 mg/m, D1, and DDP 75 mg/m, D1-3) sequential chemotherapy will be performed according to MRI or PET/CT after cisplatin-based chemoradiation. The primary outcome measure is progression-free survival, and the second outcome measures are overall survival and time to progression.

Discussion: RapidArc has an obvious advantage in improving the degree of target coverage, improving organs at risk, sparing healthy tissue, and significantly reducing the treatment time. FDG-PET/CT can increase the agreement between biopsies and delineated tumor volume and has the potential to positively impact the course of treatment. The Comet assay is attractive as a potential clinical test of tumor radiosensitivity. During radiotherapy, accurately defining disease areas is critical to avoid the unnecessary irradiation of normal tissue. Based on FDG-PET/CT and Comet assay, higher doses can be safely delivered to accurate tumor volumes, while the doses to the bladder and rectum are relatively low.

Trial Registration: ClinicalTrials.gov Protocol Registration and Results System Receipt Release Date: May 21, 2017 - Retrospectively registered. NCT03163979 .