ESTRO 2024 - Abstract Book

S974

Clinical - Gynaecology

ESTRO 2024

131

Digital Poster

Long-term assessment of clinical and PET parameters in predicting recurrence in cervical cancer

Cem Onal 1,2 , Ozan Cem Guler 1 , Nese Torun 3 , Mehmet Reyhan 3

1 Baskent University Faculty of Medicine, Department of Radiation Oncology, Adana, Turkey. 2 Baskent University Faculty of Medicine, Department of Radiation Oncology, Ankara, Turkey. 3 Baskent University Faculty of Medicine, Department of Nuclear Medicine, Adana, Turkey

Purpose/Objective:

The majority of cervical cancer studies focused on treatment outcomes and survival, but the patient populations were diverse and the number of patients followed-up on was small. There is a scarcity of data on cervical cancer patients, making it difficult to assess recurrence patterns after definitive chemordiotherapy (ChRT). Furthermore, no established metabolic biomarker accurately predicts the likelihood of recurrence at this time. The objective of this study was to assess the prognostic value of clinical factors and metabolic parameters measured using fluorodeoxyglucose positron emission tomography (FDG-PET/CT) in predicting disease recurrence, as well as distant metastasis-free survival (DMFS), local recurrence-free survival (LRFS), and overall survival (OS) in patients with cervical cancer who received definitive ChRT.

Material/Methods:

The clinical data and FDG-PET parameters, including standardized uptake value (SUV), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) of 194 patients with biopsy-confirmed squamous cell carcinoma of cervical cancer that were treated with definitive ChRT at our institution between February 2007 and August 2014 were retrospectively evaluated. Univariate and multivariate analyses were used to ascertain prognostic factors associated with DMFS, LRFS, and OS.

Results:

Median age was 57 years (range, 21–87 years). The vast majority (84%) had locally advanced disease (stage ≥IIB), with half having regional lymph node metastasis. All patients received ChRT, with a median total external RT dose of 50.4 Gy (range, 45–54 Gy) and a median total intracavitary BRT dose of 28 Gy (range, 21–28 Gy), and 158 (81.4%) received at least four cycles of concurrent chemotherapy. With a median follow-up of 12.5 years, 96 patients (49.5%) presented with disease recurrence, at a median of 9.9 months after ChRT. The 10-year OS, DMFS, and LRFS rates were 43%, 63.6%, and 71%, respectively. Primary tumor SUVmax (21.1±7.7 vs. 16.4±7.7; p=0.001), MTV (143.9±79.6 cm³ vs. 80.9±60.4 cm³; p=0.002), SUVmean (15.3±7.6 vs. 10.2 ± 5.1; p=0.001), and TLG (2386.8±1570.7 vs. 991.2±352.9; p=0.001) were significantly higher in patients with DM than in those without DM. Similarly, SUVmax (23.7±10.3 vs. 15.9±5.8; p<0.001), MTV (150.4±129.4 cm³ vs. 80.2±62.4 cm³; p=0.001), SUVmean (14.0±7.2 vs. 10.9±5.9; p=0.01), and TLG (2463.4±1859.9 vs. 1002.9±713.9; p=0.003) were also significantly different between patients with and without LR. DM and LR were significantly correlated with tumor size, SUVmax, MTV, SUVmean, and TLG values, as determined by univariate logistic regression analysis. In univariate analysis, disease stage and regional lymph node metastasis were also found to be predictors of DM. In multivariate regression analysis, lymph node metastasis [OR: 4.13 (95% CI, 2.16–7.89); p<0.001], a one-unit change in MTV [OR: 1.02 (95% CI, 1.00 – 1.04); p=0.03], and SUVmean [OR: 1.18 (95% CI, 1.04 – 1.30); p=0.007] were significantly correlated with DM, whereas SUVmax [OR: 1.15 (95% CI, 1.08 – 1.21); p<0.001] was the only predictor of LR. Lymph node metastasis, high MTV,