Research Article: Fluorodeoxyglucose Positron Emission Tomography integrated with computed tomography in carcinoma of the cervix: Its impact on accurate staging and the predictive role of its metabolic parameters

Date Published: April 18, 2019

Publisher: Public Library of Science

Author(s): Ismaheel O. Lawal, Thabo Lengana, Charl Janse van Rensburg, Florette Reyneke, Gbenga O. Popoola, Alfred O. Ankrah, Mike M. Sathekge, Giorgio Treglia.


To determine the impact of FDG-PET/CT in the initial staging of cervical cancer among women with and without HIV and to determine the abilities of FDG-PET/CT metabolic parameters in predicting the presence of distant metastasis.

We reviewed the FDG-PET/CT images of women with FIGO stage IB2 to IVA carcinoma of the cervix. We compared the FIGO stage before and after FDG-PET/CT. Maximum and mean standardized uptake values (SUVmax and SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) of the primary lesion were determined. We compared these parameters between the HIV-infected and uninfected woman and also determined their abilities to predict the presence of distant metastasis.

126 women, mean age 48.05 ± 11.80 years were studied. Seventy-three patients were HIV-infected. The disease was upstaged in 65 patients, 32 of which were upstaged to stage IVB. HIV-infected women were younger (43.36 ± 8.03 years versus 54.51 ± 13.12, p<0.001) and had more advanced disease (p = 0.022) compared with HIV-uninfected. In a univariate logistic regression adjusted for the FIGO stage of the disease, there were significant associations between MTV and TLG of the primary tumor and distant metastasis. SUVmax, SUVmean, MTV and TLG performed well in predicting the presence of distant metastasis with areas under the curves (AUCs) of 0.63, 0.66, 0.80 and 0.77 respectively. These performances improved after adjustment for the FIGO stage of the disease with AUCs of 0.80, 0.79, 0.84 and 0.82 for SUVmax, SUVmean, MTV and TLG respectively. Inclusion of 18F-FDG-PET/CT in the pre-therapy assessment of cervical cancer improves the accuracy of staging in about half of the patients. The metabolic parameters of the primary tumor perform well in predicting the presence of distant metastases.

Partial Text

Carcinoma of the cervix is one of the most common gynecological malignancies and a significant cause of cancer mortality worldwide [1–3]. Accurate staging is a necessary prerequisite to determine the most appropriate therapeutic option. The staging of disease is done according to the International Federation of Gynecology and Obstetrics (FIGO) recommendations [4]. FIGO staging entails a thorough pelvic examination, colposcopy, endocervical curettage, hysteroscopy, cystoscopy, proctoscopy, intravenous urography and radiological evaluation of the lungs and skeleton for metastasis.

A total of 126 women met our inclusion criteria and were included in this study, mean age = 48.05 ± 11.80 years. There were 73 patients (57.9%) with HIV infection while 53 patients (42.1%) were HIV-negative. About a half of our study population had a FIGO stage IIIB or IVA disease at the time of referral for FDG-PET/CT. We found SCC as the most common histological type of carcinoma of the cervix in our study population (87.3%). Other histological variants seen included adenocarcinoma (7.9%), adenosquamous (1.6%), neuroendocrine (1.6%) and other rare variants (1.6%). Table 1 shows the detailed baseline clinic-pathologic characteristics of the study population.

We evaluated the ability of FDG-PET/CT to accurately stage women diagnosed with stages IB to IVA carcinoma of the cervix and found FIGO stage migration to a higher disease state in 51.6% of patients. Patients were upstaged following imaging due to a finding of a more extensive primary tumor than assessed clinically, detection of the urinary bladder or rectal wall invasion or finding of a previously unknown site of distant metastasis. About half of the patients (49.2%) who had stage migration were upstaged to FIGO stage IVB. This stage migration may significantly impact on patients’ management. It must be said however that not all cases of stage migration may lead to a change in treatment option. Patients upstaged to stage IVB due to the detection of a previously unknown sites of distant metastases would definitely have a change in treatment option and intent, from a local/loco-regional treatment to systemic and from a curative intent to palliative treatment intent. Accurate staging of disease is a prerequisite to determining the most suitable therapeutic option. Different stages of carcinoma of the cervix are treated in different ways. Patients with early-stage disease may be offered radical hysterectomy with or without lymphadenectomy followed by adjuvant therapy [12], while patients with locally advanced disease are commonly treated with pelvic radiotherapy with or without concurrent chemotherapy [13,14]. Patients with advanced disease (stage IVB) are treated with single or combination chemotherapy [13]. We demonstrated the sites of metastases in 88 patients with the lymph nodes (pelvic and extra-pelvic) being the most common sites of metastases. The clinical importance of this is that the managing team can decide on the optimum therapy among the available options and as well as guide the field of radiotherapy or extent of surgery.

In women with cervical carcinoma, the inclusion of FDG-PET/CT in the pre-therapy assessment improved the accuracy of staging in about of half of patients. FDG-PET metabolic metrics can accurately predict individuals with distant metastases. These metabolic parameters and pattern of metastases are not significantly different between HIV-infected and HIV-uninfected patients.