Why avoid the hippocampus? A comprehensive review

• Published in: Radiotherapy and oncology Vol. 97; no. 3; pp. 370 - 376
• Main Authors: Gondi, Vinai, Tomé, Wolfgang A., Mehta, Minesh P.
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier Ireland Ltd 01.12.2010
• Subjects: Brain metastases; Brain Neoplasms - pathology; Brain Neoplasms - radiotherapy; Brain Neoplasms - secondary; Cognition Disorders - etiology; Cranial Irradiation - adverse effects; Cranial Irradiation - methods; Disease Progression; Executive Function - radiation effects; Hematology, Oncology and Palliative Medicine; Hippocampal sparing; Hippocampus - radiation effects; Humans; Memory - radiation effects; Neurocognitive function; Psychomotor Performance - radiation effects; Radiotherapy Dosage; RTOG 0933; Whole-brain radiotherapy; Word Association Tests; Brain metastases; RTOG 0933; Hippocampal sparing; Whole-brain radiotherapy; Neurocognitive function
• ISSN: 0167-8140; 1879-0887; 1879-0887
• DOI: 10.1016/j.radonc.2010.09.013

In this review article, we provide a detailed and comprehensive discussion of the rationale for using modern IMRT techniques to spare the subgranular zone of the hippocampus during cranial irradiation. We review the literature on neurocognitive effects of cranial irradiation; discuss clinical and preclinical data associating damage to neural progrenitor cells located in subgranular zone of the hippocampus with radiation-induced neurocognitive decline, specifically in terms of short-term memory formation and recall; and present a review of our pilot investigations into the feasibility and risks of sparing the subgranular zone of the hippocampus during whole-brain radiotherapy for brain metastases. We also introduce our phase II cooperative group clinical trial (RTOG 0933) designed to prospectively evaluate the postulated neurocognitive benefit of hippocampal subgranular zone sparing and scheduled to open in 2010.