Intensity Modulated Radiation Therapy and Concurrent Chemotherapy for Locally Advanced Cervical Cancer Not Amenable to Brachytherapy

Abstract

<h3>Hypothesis</h3> Cervical cancer patients ineligible for brachytherapy due to tumor geometry suffer poor local control and survival outcomes despite treatment with concurrent IMRT and chemotherapy. <h3>Purpose/Objective(s)</h3> In this study of patients with cervical cancer tumors too large for brachytherapy boost, we report tumor control and toxicity outcomes of patients treated with intensity modulated radiation therapy (IMRT) and concurrent chemotherapy. <h3>Materials/Methods</h3> We performed a retrospective study of patients with FIGO 2018 stage III-IVB cervical cancer treated with high dose IMRT and concurrent cisplatin without brachytherapy at a tertiary academic center from 2005 – 2020. All patients underwent FDG-PET/CT and were examined by an experienced gynecologic brachytherapist. Patients received 48.6-50.4 Gy in 25 to 35 fractions to the cervix, pelvis, and if involved on FDG-PET, paraaortic, and supraclavicular lymph nodes with IMRT. Lymph nodes greater than 3 cm received a simultaneous boost to a total dose of 60 Gy. The primary metabolically active cervical tumor received a simultaneous or sequential boost without additional planning margin to a total dose of 60-70.2 Gy with concurrent weekly cisplatin or carboplatin. Toxicity is reported with CTCAEv5. <h3>Results</h3> Twenty patients out of 1005 (2%) were identified with median age of 55 (range 37 – 76) years. Sixty percent were Caucasian, 35% black, 5% Asian. Median metabolic primary tumor volume was 111 cm3 (range 26 – 473). Nineteen (95%) had squamous histology and one (5%) had adenosquamous. Median follow up was 15 months (range 2 - 154). 7 (35%) patients had PET positive pelvic lymph nodes, 5 (25%) paraaortic, and 3 (15%) supraclavicular. Classic FIGO stage was: III 7 (35%), IVA 11 (55%), IVB 2 (10%). FIGO 2018 stage was: III 3 (15%), IVA 9 (45%), IVB 8 (40%). Five (20%) patients were disease free at the end of follow up (III 1 (33%), IVA 3 (33%), IVB 1 (13%)). One- and 2-year freedom from local progression were 70% and 60%, respectively. One and 2-year OS were 60% and 35%, respectively. Grade 3 anemia and nausea occurred in 4 (20%), and 2 (10%) patients, respectively. Grade 4 diarrhea and nausea occurred in 1 (5%) and 3 (15%) patients, respectively. Two (10%) patients died of treatment-related toxicity. <h3>Conclusion</h3> Our study shows that patients ineligible for brachytherapy suffer poor local control and survival outcomes. Grade 4-5 toxicity occurred in 25% of patients. Novel radiation techniques for this patient population should be further explored.