Inclusion Criteria:  Females aged ≥18 years Histologically confirmed cervical squamous, adeno-, or adenosquamous carcinoma 2018 Fédération Internationale de Gynécologie et d'Obstétrique (FIGO) Stage IIIA-IIIC1, IVA Pelvic nodal metastases (for the phase 1 cohorts) Contraindication to chemotherapy Brachytherapy candidate World Health Organization (WHO)/ECOG performance status of ≤2 Life expectancy of at least 12 weeks Adequate bone marrow function: Absolute neutrophil count ≥1,500 cell/mm3; Platelets ≥100,000 cell/mm3; Hemoglobin ≥10.0 g/dL; Leukocyte count ≥4,000 cell/mm3  Exclusion Criteria:  Other histology (small cell, neuroendocrine, lymphoma, sarcoma, etc.) 2018 FIGO Stage IIIC2 (para-aortic nodal metastases) Clinical and/or radiologic evidence of metastatic disease History of another malignancy except for the following: malignancy treated with curative intent and with no known active disease ≥5 years and of low potential risk for recurrence; adequately treated non-melanoma skin cancer or lentigo maligna without evidence of disease; adequately treated carcinoma-in-situ without evidence of disease Pregnancy Uncontrolled concurrent illness, including but not limited to, ongoing or active infection, symptomatic congestive heart failure, uncontrolled hypertension, unstable angina pectoris, uncontrolled cardiac arrhythmia, active interstitial lung disease, serious chronic GI conditions associated with diarrhea (including Crohn's disease or ulcerative colitis), or psychiatric illness/social situations that would limit compliance with study requirement, substantially increase risk of incurring adverse events or compromise the ability of the patient to give written informed consent Presence of any psychological, familial, sociological, or geographical condition potentially hampering compliance with the study protocol and follow-up schedule, including alcohol dependence or drug abuse Prior hysterectomy Prior treatment for cervical cancer Prior pelvic radiotherapy Concomitant anti-cancer therapy