RT Journal Article SR Electronic T1 Prognostic value of pretreatment FDG PET/CT in uterine cervical cancer: significance of histopathological subtypes JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 352 OP 352 VO 61 IS supplement 1 A1 Tomoaki Otani A1 Yuji Nakamoto A1 Takayoshi Ishimori A1 Tsuneo Saga A1 Kaori Togashi YR 2020 UL http://jnm.snmjournals.org/content/61/supplement_1/352.abstract AB 352Objectives: There are two major histopathological subtypes in uterine cervical carcinoma: squamous cell carcinoma (SCC) and adenocarcinoma (AC). FDG-PET/CT (PET/CT) has been reported to have a prognostic value in various malignancies, including uterine cervical cancer, but its prognostic value for each histopathological type has not been fully investigated. The aim of this study was to assess the prognostic value of pretreatment PET/CT in cervical cancer according to histopathological types. Methods: We retrospectively analyzed 83 SCC patients and 35 AC patients (age: 22-95 yr) who underwent pretreatment PET/CT. Quantitative indices, such as SUVmax, SUVmean, metabolic tumor volume (MTV), and total lesion Glycolysis (TLG) of primary tumor were calculated for each patient. These parameters and tumor size were compared using Mann-Whitney’s U test between AC and SCC. The receiver-operating-characteristic analysis was performed to determine the optimal cut-off values for SUVmax, SUVmean, MTV, and TLG. Kaplan-Meier analysis and log-rank test were used to estimate and compare the correlation between each PET parameter and progression-free survival (PFS)/Overall survival (OS). The prognostic value of the imaging parameters and clinical parameters including age, FIGO stage, histological subtype was assessed using univariate Cox proportional hazard model. Results: The median follow-up duration was 27 (range: 6-85) months in SCC and 28 (range: 6-72) months in AC. In SCC, at the time of last follow-up, 64 (77 %) were alive without recurrence, 19 (23 %) were developed recurrence, and 10 (12 %) were died from the disease progression. In AC, 25 (71 %) patients were alive without recurrence, 10 (29 %) were developed recurrence, and 4 (11 %) were died from the disease progression. In SCC, 19 (23%) patients had PET positive pelvic lymph nodes, and 12 (14%) patients had para-aorta lymph nodes. In AC, 8 (23%) patients had PET positive pelvic lymph nodes, and 4 (11%) patients had para-aorta lymph nodes.The values of SUVmax, SUVmean, MTV and TLG of SCC patients were 14.9±6.4, 8.0±3.2, 32.2±37.1, and 283.9±345.5, respectively, and those of AC patients were 10.5±7.6, 6.3±4.7, 21.5±23.1, and 121.6±127.7, respectively. The SUVmax, SUVmean, and TLG of SCC were higher than those of AC (p<0.01, <0.01, and <0.01, respectively). There was no significant difference in MTV between the two groups (p=0.10). Tumor size in SCC was significantly larger than that in AC (42.5±16.5 mm vs 35.0±18.6 mm, p=0.02).In SCC, the Kaplan-Meier curves for PFS and OS indicated better outcomes for the lower groups in SUVmax, SUVmean, MTV and TLG (p=0.05, p=0.03, p=0.02, p<0.01 for PFS, and p=0.15, p=0.25, p=0.13, p=0.02 for OS, respectively). On the other hand, in AC, they indicated better outcomes for the lower groups in MTV and TLG (p<0.01, p<0.01 for PFS, and p<0.01, p<0.01 for OS), while SUVmax and SUVmean were not related to PSF and OS (p=0.42, p=0.52 for PSF, and p=0.73, p=0.97 for OS). As for univariate analysis, in SCC, higher SUVmax, SUVmean, MTV, and TLG correlated significantly with poorer PFS (p=0.04, 0.03, <0.01, and <0.01, respectively) and MTV, TLG, and tumor size correlated significantly with poorer OS (p=0.04, <0.01, and 0.02, respectively). In AC, MTV, TLG, tumor size, age, and FIGO stage correlated significantly with poorer PFS (p<0.01, <0.01, <0.01, <0.01, and <0.01, respectively) and MTV, TLG, and tumor size, and FIGO stage correlated significantly with poorer OS (p<0.01, <0.01, <0.01, and <0.01, respectively) Conclusions: Our preliminary data suggest that PET/CT would be useful for predicting prognosis in cervical cancer, but clinical significance of quantitative values may be different according to histopathological types.