Evaluation of metabolic uptake in gynecological organs using FDG-PET in women diagnosed with nongynecological malignancies.

Background/aim: Gynecological malignancies, including those affecting the uterus, cervix, vagina, vulva, and adnexa, pose significant physical and psychosocial burdens. Early detection and effective management of these malignancies are critical for improving outcomes. This study aims to evaluate metabolic uptake patterns in gynecological organs using fluorodeoxyglucose positron emission tomography (FDG-PET) and to analyze their malignancy potential in women with nongynecological cancers.

Materials and methods: A retrospective analysis was conducted on 221 women with nongynecological malignancies who exhibited pathological FDG uptake in gynecological organs on FDG-PET/CT imaging. Lesions were evaluated based on the standardized uptake value maximum (SUVmax), morphological characteristics on contrast-enhanced CT, and further gynecological assessment using ultrasonography, biopsy, and endometrial sampling. Statistical analyses, including the receiver operating characteristics curve and descriptive statistics, were performed using SPSS software, with significance set at p < 0.05.

Results: Pathological FDG uptake was observed in the uterus (60.6%), adnexa (30.3%), cervix (14.02%), vulva (4%), and vagina (2.2%). The mean SUVmax of lesions varied across sites, with uterine lesions showing a mean SUVmax of 6.96 ± 3.55. An SUVmax cutoff of >10.11 predicted malignancy in uterine lesions with 86% sensitivity and 82% specificity. Among patients with uterine involvement, malignancy was confirmed in 10 cases, all of whom were on tamoxifen therapy. Endometrial thickness was significantly higher in malignancy cases (10.6 mm vs. 5.8 mm, p = 0.014). Ultrasonography and biopsy findings largely confirmed the benign nature of other lesions, highlighting the role of multimodal diagnostic approaches.

Conclusion: FDG-PET imaging is a valuable tool for identifying metabolic activity in gynecological organs and for differentiating malignant lesions from benign ones. High SUVmax values and endometrial thickness are significant indicators of malignancy, particularly in patients undergoing hormonal therapy. This study underscores the importance of integrating metabolic imaging with clinical and morphological assessments for the early detection and management of gynecological malignancies.