Headshot of a smiling woman with light skin tone and dark hair wearing a white top and silver heart chain necklace against a blurred outdoor background

Katrina O'Halloran, MD, MS

Attending Physician
Assistant Professor of Clinical Pediatrics, Keck School of Medicine of USC
Clinical Interests

Brain and spinal cord tumors in children; liquid biopsy; precision medicine


Medical School

University College Dublin, National University of Ireland

Graduate School

University of Southern California


UPMC Children's Hospital of Pittsburgh


UPMC Children's Hospital of Pittsburgh


Children's Hospital Los Angeles



Pediatrics, American Board of Pediatrics (2018)
Pediatric Hematology-Oncology, American Board of Pediatrics (2023)

Professional Memberships

Children's Oncology Group (COG)
Society for Neuro-Oncology (SNO)
International Society of Paediatric Oncology (SIOP)


O'Halloran K, Yellapantula V, Christodoulou E, Ostrow D, Bootwalla M, Ji J, Cotter J, Chapman N, Chu J, Margol A, Krieger MD, Chiarelli PA, Gai X, Biegel JA. Low-pass whole-genome and targeted sequencing of cell-free DNA from cerebrospinal fluid in pediatric patients with central nervous system tumors. Neurooncol Adv. 2023 Jan-Dec;5(1):vdad077.

Christodoulou E, Yellapantula V, O'Halloran K, Xu L, Berry JL, Cotter JA, Zdanowicz A, Mascarenhas L, Amatruda JF, Ostrow D, Bootwalla M, Gai X, Navid F, Biegel JA. Combined low-pass whole genome and targeted sequencing in liquid biopsies for pediatric solid tumors. NPJ Precis Oncol. 2023 Feb 20;7(1):21.

Plant-Fox AS, O'Halloran K, Goldman S. Pediatric brain tumors: the era of molecular diagnostics, targeted and immune-based therapeutics, and a focus on long term neurologic sequelae. Curr Probl Cancer. 2021 Aug;45(4):100777.

Kaneva K, O'Halloran K, Triska P, Liu X, Merkurjev D, Bootwalla M, Ryutov A, Cotter JA, Ostrow D, Biegel JA, Gai X. The spectrum of mitochondrial DNA (mtDNA) mutations in pediatric CNS tumors. Neurooncol Adv. 2021 Jan-Dec;3(1):vdab074.

Triscott J, Lee C, Foster C, Manoranjan B, Pambid MR, Berns R, Fotovati A, Venugopal C, O'Halloran K, Narendran A, Hawkins C, Ramaswamy V, Bouffet E, Taylor MD, Singhal A, Hukin J, Rassekh R, Yip S, Northcott P, Singh SK, Dunham C, Dunn SE. Personalizing the treatment of pediatric medulloblastoma: Polo-like kinase 1 as a molecular target in high-risk children. Cancer Res. 2013 Nov 15;73(22):6734-44.