The value of F-18 FDG-PET in invasive cervical cancer
Uterine Cervical Cancer is one of the leading causes of morbidity amongst the female genital tract cancers. This study aims to identify the Value of Fluorine-18 - FluorinedeoxyGlucose – Positron emission tomography scan in cervical cancer. Currently, the International Federation of Gynaecology and Obstetrics (FIGO) staging is the routine method used internationally for staging of cervical cancer. This staging is based on clinical criteria and does not take into account para-aortic lymph nodes or pelvic lymph node involvement, which may affect the radiation target volumes. F-18- FDG-PET/CT scanning can identify metabolically active lymph nodes as well as distant metastases including para-aortic lymph nodes. This method aims to show that many patients in our setting have distant metastases; hence the current FIGO staging method may not be a very accurate method of staging in the Pre-treatment setting. F-18 FDG-PET/CT was done post radiation therapy to assess response to treatment. Post treatment F-18 FDG PET/CT was correlated to clinical findings and responses after radiation. Radiation target volumes may be modified in future if para-aortic lymph nodes are found on pre-treatment F-18 FDG-PET/CT scan and extended field radiation will then be used. When a large primary tumour is found with no disease beyond the pelvis, patients may benefit from 3D Brachytherapy. Methodology: This was a prospective randomised trial done at Charlotte Maxeke Johannesburg Academic Hospital, between May 2010 and Jan 2012 .After the routine tests were done and patients staged according to FIGO staging, patients had a Pre-Radiation F-18 FDG-PET/CT scan, followed by a post therapy F-18 FDG-PET/CT scan 3 months after treatment. Patients were stratified from clinical stages IBi to stage IIIB.All patients were biopsy confirmed with invasive cervical cancer. Results: In future, the role of F-18 FDG-PET/CT will be an important modality in the initial staging as well as in the post therapy setting to assess the response of radiation in cervical cancer. The results showed that there was no association between FIGO clinical staging and findings in a pre-radiation F-18 FDG -PET/CT scan as para-aortic lymph nodes were not detected by FIGO staging. Conclusion: The current staging used for cervical cancer does not correlate with pre -treatment PET findings. A large proportion of patients were upstaged by F-18 FDG-PET/CT scan. A proportion of patients were not identified prior to F-18 FDG- PET/CT scan, as having distant metastases. The value of F18 FDG-PET/CT scan may have an impact on the future management of patients with cervical cancer. PET in the post therapy setting is also a good surrogate endpoint for determining tumour control as well as residual and metastatic disease.