(P006) The Role of Sequential Imaging in Cervical Cancer Management

A. MacDonald, C. Tung, M. Bonnen, M.Y. Williams-Brown, C.R. Diaz-Arrastia, M. Ludwig, M.L. Anderson; UT Health Science Center at Houston; Baylor College of Medicine

OBJECTIVES: In the absence of International Federation of Gynecology and Obstetrics (FIGO) guidelines, optimal imaging of women diagnosed with cervical cancer in settings where multiple modalities are available for treatment planning remains unclear. The purpose of this study was to determine whether sequential imaging by contrast-enhanced computed tomography (CT), 18-fluoro-deoxyglucose positron emission tomography (FDG-PET)-CT, and/or magnetic resonance imaging (MRI) enhances radiation treatment planning for women with cervical cancer.

METHODS: After obtaining institutional review board (IRB) approval, all women diagnosed with cervical cancer who were eligible for definitive chemoradiation (FIGO stages IB1–IVA) in a regional safety-net health system between July 2012 and August 2014 were identified. Clinical demographics and treatment plans were reviewed and abstracted so that the impact of imaging modalities could be compared.

RESULTS: A total of 93 women (mean age: 51.0 ± 13.2 yr) with IB1 (n = 3, 3.2%), IB2 (n = 16, 17.2%), IIA (n = 11, 11.8%), IIB (n = 33; 35.4%), IIIA (n = 5, 5.3%), IIIB (n = 22;23.7%), and IVA (n = 3; 3.2%) disease were identified. Histologies included squamous cell (n = 78, 83.8%), adenosquamous (n = 2, 2.1%), poorly differentiated (n = 3, 3.2%), small cell (n = 1, 1.1%), and adenocarcinomas (n = 9, 9.6%). Pretreatment, 48 women underwent contrast-enhanced CT (abdomen/pelvis and/or chest) alone, 28 received CT followed by PET, 6 received PET and MRI, 4 received CT and MRI, 1 received PET only, and 6 underwent all three tests. For the 34 women who had CT followed by PET, no anatomic findings were identified by CT that were not also detected by PET. In contrast, PET identified lesions that were not seen in anatomic fields evaluated by CT in eight women. PET resulted in radiation treatment modifications for 22 (65%) of these women. Of the 12 patients who received PET and MRI, treatment was modified in response to PET but not MRI for 8 (67%). Treatment modifications due to PET included nodal boost (n = 20, 67%), extension of irradiated field (n = 8, 26%), or both (n = 2, 7%).

CONCLUSIONS: Despite uncertainty regarding the anatomic resolution of PET, sequential use of contrast-enhanced CT, PET-CT, and/or MRI had no impact on treatment planning that was not accomplished by the use of PET alone. Future work should focus on determining the optimal pretreatment imaging for women with cervical cancer and developing guidelines to optimize outcomes while minimizing cost and radiation exposure.

Proceedings of the 97th Annual Meeting of the American Radium Society - americanradiumsociety.org