SUMMARY
Roman O. Kowalchuk, M.D., develops biologically guided local therapy strategies for pediatric solid tumors. Dr. Kowalchuk's work focuses on osteosarcoma, Ewing sarcoma, rhabdomyosarcoma, medulloblastoma and diffuse midline glioma. Through his research, Dr. Kowalchuk aims to improve local tumor control while limiting injury to healthy tissues by integrating tumor biology, radiation response and biomarkers into treatment design.
Dr. Kowalchuk studies mechanisms of radiation resistance, including adaptive DNA damage responses and dependencies involving ataxia-telangiectasia mutated (ATM) and DNA-dependent protein kinase. He also investigates spatially fractionated and minibeam radiation approaches, multimodal liquid biopsy strategies and biomarker-informed treatment adaptation.
Dr. Kowalchuk's translational program connects mechanistic studies with prospective clinical trials. This approach tests biologically selected radiation escalation, altered treatment sequencing and approaches that reduce unnecessary radiation exposure.
Focus areas
- Radiation resistance in osteosarcoma. Dr. Kowalchuk investigates how osteosarcoma cells survive radiation through adaptive DNA damage responses. He studies complementary repair pathways involving ATM and DNA-dependent protein kinase. Dr. Kowalchuk also evaluates whether combined pathway inhibition can produce clinically useful radiosensitization in a radioresistant pediatric solid tumor.
- Biologically adapted radiation therapy. Dr. Kowalchuk develops local treatment strategies that match radiation intensity and delivery to tumor biology. He studies spatially fractionated radiation therapy and minibeam radiation therapy. Dr. Kowalchuk also explores approaches that modify treatment volumes or doses to improve tumor control while reducing unnecessary exposure of healthy tissues.
- Multimodal cancer biomarkers. Dr. Kowalchuk develops liquid biopsy approaches that combine circulating tumor DNA, methylation profiling, fragment patterns and extracellular vesicles. He uses these complementary signals to improve disease detection and risk assessment when single-analyte approaches may be insufficient. Dr. Kowalchuk also identifies patients who may benefit from altered local therapy.
- Biomarker-integrated clinical trials. Dr. Kowalchuk translates biological hypotheses into prospective studies in pediatric cancers. He incorporates serial biospecimen collection and treatment adaptation into trials involving Ewing sarcoma, diffuse midline glioma and rhabdomyosarcoma. Dr. Kowalchuk uses these methods to link biological features to clinical decisions about radiation dose, sequencing and multimodality therapy.
Significance to patient care
Children with solid tumors may need strong treatment focused on the tumor to control cancer. But radiation also can damage healthy tissue and cause long-term side effects.
Dr. Kowalchuk's research aims to make radiation treatment more precise. He works to identify tumors that need stronger treatment and find ways to help resistant tumors respond better. Dr. Kowalchuk also studies when radiation can be reduced if the biology of the tumor suggests it may not be needed.
Dr. Kowalchuk's work with biomarkers and clinical trials also may help medical teams identify treatment risks earlier. This research may help care teams choose treatments based more directly on the needs of each patient.