The Association of Tumor Burden by 18F-FDG PET/CT and Survival in Vulvar Carcinoma

PURPOSE The aim of this study was to assess the impact of 18F-FDG PET/CT metabolic parameters obtained at initial staging of vulva carcinoma on survival in women with and without HIV infection. PATIENTS AND METHODS 18F-FDG PET/CT images of women with vulva cancer who are planned for definitive therapy were analyzed. SUVmax, SUVmean, MTV, and total lesion glycolysis (TLG) as well as whole-body MTV and whole-body TLG were computed. RESULTS Twenty-five women were included with a mean age of 43.44 ± 10.32. The majority of the patients were HIV infected with a median CD4 count of 444.00 cells/mm3. The HIV-infected women are younger at diagnosis than their HIV-uninfected counterparts. All patients presented with inguinofemoral lymph node involvement, whereas half the patients had pelvic nodal metastasis. All the patients with distant visceral or skeletal metastasis were HIV infected. The lungs were the most common site of distant metastasis. When comparing the SUVmax, SUVmean, MTV, TLG, wbMTV, and wbTLG between HIV-infected and HIV-uninfected patients, we did not find statistical differences. Twelve patients (48%) were upstaged to metastatic disease. Seven patients had died at the time of analysis. The wbMTV and wbTLG were significantly higher in nonsurvivors than survivors. CONCLUSIONS 18F-FDG PET/CT improves initial staging of squamous cell carcinoma among women with and without HIV infection. The whole-body tumor burden assessed by 18F-FDG PET metabolic metrics did not differ between HIV-infected and HIV-uninfected women. A higher whole-burden tumor burden is associated with a higher risk of mortality among women with vulva cancer.