Positron emission tomography for staging locally advanced cervical cancer and assessing intensity modulated radiotherapy approach.

Abstract

To evaluate toxicity and outcome of concomitant chemotherapy and intensity modulated radiotherapy (IMRT) with 18-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) based simultaneous integrated boost (SIB) of locally advanced cervical cancer (LACC). Patients with LACC underwent chemo-radiation with IMRT and SIB. Staging and follow-up were performed with clinical evaluation and CT, MRI, 18FDG-PET/CT. SIB was done on positive nodes with 18FDG-PET/CT based planning. CT-based planning high-dose-rate brachytherapy (HDR-BT) was delivered as subsequent boost to the primary tumor. Cisplatin concomitant chemotherapy was administered during IMRT. Fourteen patients with cervical cancer were prospectively recruited between August 2014 and June 2017, 13 (93%) had a LACC, one (7%) patient was not evaluable because 18FDG-PET/CT evidenced metastases to the liver undetected by previous CT/MRI. Patients had a median age of 59years, a median Karnofsky performance status of 100%, and a prevalence of squamous cell carcinoma histology (85%). SIB was delivered on 23 positive lymph nodes. IMRT median dose to the pelvis was 48.6Gy in 27 fractions, SIB median dose 54Gy in 27 fractions, HDR-BT boost median dose 21Gy in 3 fractions. After a median follow-up of 30months, 2-year local control and distant control were 86% and 86%, respectively. There were no grade 4 acute and/or late toxicities. The 18FDG-PET/CT influenced stage assessment and RT treatment planning due to its high specificity in distant metastases and nodal involvement detection. The IMRT with SIB for positive nodes was an effective therapy with acceptable toxicity in LACC.