A Phase II Study of Extended Field IMRT External Beam Irradiation and Intracavitary Brachytherapy

Overview

Recent studies have shown that the chance of survival among women with advanced cervical cancer is increased when they receive concurrent chemotherapy and radiation to the pelvis. However, patients who have advanced disease show loco-regional failure as well as a high incidence of distant metastasis. Positron emission tomography (PET) scanning has high sensitivity and specificity in the detection of pelvic and para-aortic lymph node metastases. While the detection of para-aortic metastases by PET significantly impacts prognosis, PET has been known to show positive lymph node metastasis in the pelvis only while not detecting micrometastatic disease in the para-aortic lymph nodes (despite the fact that they are histologically known). In addition, patients with positive para-aortic lymph nodes on PET, greater amounts (more than 45 Gy) of radiation must be used to improve the probability of controlling the cancer. However, doses greater than this have been limited because of the dose and volume limits to the small bowel. But, Intensity Modulated Radiation Therapy (IMRT) is a new way of calculating and delivering radiation therapy. Compared to external beam radiation, IMRT has the improved ability to deliver large doses of radiation to specific targets while minimizing the exposure to surrounding normal tissue. With IMRT, however, the effective dose/volume can be increased more safely and lower the toxicity of surrounding tissue, thus making prophylactic dosing to para-aortic lymph nodes not detected by PET safer and more effective.

Prior to entrance on the study, patients will undergo a history and physical and evaluation of Karnofsky Performance Status. They will have a biopsy of their tumor and will undergo a fluorodeoxyglucose (FDG) PET scan and must include evaluation of para-aortic lymph nodes. Blood work will be done (complete blood count (CBC), differential, platelets, blood urea nitrogen(BUN), serum creatinine, bilirubin, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase. Also, pre-treatment, patients will receive a chest x-ray and an intravenous push (IVP) (unless a computed tomography (CT) with contrast has been performed). Additionally, patient may undergo a CT, magnetic resonance (MRI) and/or lymphangiogram. Patients will then be registered to a treatment arm, depending on the outcome of their PET scan. Patients with positive pelvic lymph nodes but no positive para-aortic lymph nodes by PET will be assigned to Treatment Arm 1. Patients with positive pelvic lymph nodes and positive para-aortic lymph nodes by PET will be assigned to treatment arm 2. Treatment Group 1. Either a conventional or CT simulation may be performed. Patients will be treated with IMRT extended field external beam radiation therapy (to cover pelvis and para-aortic lymph nodes) and intracavitary radiation (6 high dose radiation (HDR) treatments) concurrently with cisplatin (40 mg/m\^2/week) Treatment Group 2. A CT simulation must be performed. Patients will be treated with extended field external beam radiation therapy to the pelvis and with IMRT to cover the para-aortic lymph nodes to 60 Gy, 50.4 Gy to the para-aortic lymph node bed in conjunction with external beam pelvic radiation therapy as appropriate for disease stage and intracavitary radiation (6 HDR treatments) concurrently with cisplatin (40 mg/m\^2/week).