Radiation Injury and Reconstruction — Radiobiology, Timing, and Surgical Strategy

This episode provides a comprehensive review of radiation injury and its implications for reconstructive surgery, focusing on radiobiology, tissue toxicity, and surgical decision-making. The discussion begins with the fundamentals of ionizing radiation, including free radical formation, DNA damage, and the role of oxygen-dependent injury.Key principles of radiobiology are reviewed, including the Four Rs (Repopulation, Redistribution, Repair, Reoxygenation) and the differential sensitivity of the cell cycle (M-phase most sensitive, S-phase most resistant).The episode outlines the timeline of radiation injury, distinguishing acute toxicity (reversible inflammation and desquamation) from late toxicity, characterized by irreversible fibrosis driven by TGF-beta signaling, resulting in the classic “Four Hs”: hypovascularity, hypoxia, hypocellularity, and hyper-signaling.Clinical implications for reconstruction are discussed in depth, including the impact of post-mastectomy radiation therapy (PMRT) on implant-based reconstruction, with high rates of capsular contracture and implant failure, as well as the effects of radiation on autologous tissue (fat necrosis and volume loss).Reconstructive strategies are emphasized, including the delayed-immediate approach, using tissue expanders as placeholders followed by definitive autologous reconstruction in non-radiated tissue. Additional topics include microvascular surgery in radiated fields, pharmacologic management of fibrosis (pentoxifylline and vitamin E), and complications such as osteoradionecrosis (ORN) and radiation-induced malignancies.Part of Dr. Lara’s Plastic Surgery Compendium — a surgeon-level audio reference built from primary textbooks and surgical literature.Topics Covered radiation injury plastic surgery, radiobiology Four Rs, M phase radiation sensitivity, TGF beta fibrosis radiation, PMRT breast reconstruction complications, capsular contracture radiation implant, delayed immediate breast reconstruction, osteoradionecrosis mandible ORN, pentoxifylline vitamin E radiation fibrosis, radiation induced malignancy Cahan criteria, plastic surgery board reviewDisclaimerThis podcast is intended for educational purposes only and is designed for medical students, residents, fellows, and practicing healthcare professionals. It is not intended to provide medical advice, diagnosis, or treatment for any individual patient. The content presented reflects general surgical principles and should not be used as a substitute for formal medical training, clinical judgment, or consultation with qualified healthcare professionals. Listening to this podcast does not establish a physician–patient relationship.