Testing the Addition of a New Anti-Cancer Drug, Triapine, to the Usual Chemotherapy Treatment (Cisplatin) During Radiation Therapy for Advanced-stage Cervical and Vaginal Cancers

Inclusion Criteria: * Patient has a new, unrated histologic diagnosis of stage IB2 (\> 4 cm), II, IIIB or IVA squamous, adenocarcinoma, or adenosquamous carcinoma of the uterine cervix (FIGO 2009) or stage II-IVA squamous, adenocarcinoma, or adenosquamous carcinoma of the vagina not amenable to curative surgical resection alone; the presence or absence of para-aortic lymph node metastasis will be based on pre-therapy 18F-FDG PET/CT; NOTE: if the baseline 18F-FDG PET/CT identifies hypermetabolic para-aortic disease, such patients will NOT be eligible; the patient must be able to tolerate imaging requirements of an 18F-FDG PET/CT scan * Patient must provide study specific informed consent prior to study entry * Patient must have a Gynecologic Oncology Group (GOG) performance status of 0, 1, or 2 or equivalent * Absolute neutrophil count \> 1,500/uL * Platelets \> 100,000/uL * Hemoglobin \> 10 g/dL * Total bilirubin \< 2.0 mg/dL * Aspartate aminotransferase (AST) (serum glutamic oxaloacetic transaminase \[SGOT\])/alanine aminotransferase (ALT) (serum glutamate pyruvate transaminase \[SGPT\]) \< 2.5 X institutional upper limit of normal * Prothrombin time (PT)/activated partial thromboplastin time (aPTT) \< 1.5 X institutional upper limit of normal * Creatinine =\< 1.5 mg/dL to receive weekly cisplatin * Patients whose serum creatinine is between 1.5 and 1.9 mg/dL are eligible for cisplatin if the estimated creatinine clearance (CCr) is \>= 30 ml/min; for the purpose of estim…