This is a grant to conduct correlative science associated with an ongoing NCI-sponsored multi-center cooperative group phase 3 trial (NRG-GY006; NCT02466971). Specifically, this R01 grant pertains to Aims 1.3.7 and 1.3.8 of that trial protocol. The primary objective of the NRG-GY006 is to test the hypothesis that the addition of triapine to standard chemoradiation with concurrent cisplatin can improve overall survival relative to the standard of care. Patients are randomized 1:1 between the experimental (i.e., triapine) and control (i.e., standard of care) arms. The present R01 grant seeks to investigate the effect of image-guided intensity modulated radiation therapy (IG-IMRT) relative to conventional RT on normal tissue toxicity and hematopoietic compensatory response. The investigators will compare 3 methods of delivering external beam radiation therapy: conventional 3D conformal radiotherapy (3DRT), positron emission tomography (PET)-based IG-IMRT, and atlas-based IG-IMRT. Patients are not randomized between the 3 types of radiation; rather, sites treat using 3DRT as a default, and are required to undergo additional credentialing for IG-IMRT. Once credentialed for IG-IMRT, sites are allowed only to treat with IG-IMRT in order to mitigate selection bias. Patients treated on the trial using IG-IMRT prior to 5/13/2019 (demarcating the conversion from phase 2 to phase 3) were treated with PET-based IG-IMRT. Patients treated on the trial using IG-IMRT after 5/13/2019 are treated with atlas-based IG-IMRT. Thus, there are potentially 6 groups to compare (2 chemotherapy arms and 3 RT modalities). The specific aims of the grant are as follows: Aim 1A: To test the hypothesis that multi-atlas-based IGRT reduces acute hematologic toxicity and improves chemotherapy delivery compared to conventional RT Aim 1B: To test the hypothesis that multi-atlas-based IGRT results in comparable acute hematologic toxicity and chemotherapy delivery compared to PET-based IGRT Aim 2A: To test the hypothesis that triapine reduces extra-pelvic compensatory hematopoiesis relative to therapy with cisplatin only Aim 2B: To test the hypothesis that IGRT (multi-atlas-based or PET-based) increases pelvic compensatory hematopoiesis relative to conventional radiotherapy Aim 3: To develop and validate a radiomics model for gynecologic cancer treatment outcomes that incorporates whole body imaging biomarkers of the inflammatory state and correlates with the effectiveness of triapine.