Int J Radiat Oncol Biol Phys. 2023 Jul 21:S0360-3016(23)07647-2. doi: 10.1016/j.ijrobp.2023.07.015. Online ahead of print.
ABSTRACT
BACKGROUND: Radiation necrosis (RN) secondary to stereotactic radiosurgery is a significant cause of morbidity. The optimal management of corticosteroid-refractory brain RN remains unclear.
OBJECTIVE: To summarise the literature specific to efficacy and toxicity of treatment paradigms for patients with symptomatic corticosteroid refractory RN. To provide consensus guidelines for grading and management of RN on behalf of the International Stereotactic Radiosurgery Society (ISRS).
METHODS: A systematic review of articles pertaining to treatment of RN with bevacizumab, laser interstitial thermal therapy (LITT), surgical resection, or hyperbaric oxygen therapy (HBOT) was performed. The primary composite outcome was clinical and/or radiological stability/ improvement (i.e., proportion of patients achieving improvement or stability with the given intervention). Proportions of patients achieving the primary outcome were pooled using random weighted-effects analysis, but not directly compared between interventions.
RESULTS: Twenty-one articles were included, of which only two were prospective studies. Thirteen reports were relevant for bevacizumab, 5 for LITT, 5 for surgical resection and 1 for HBOT. Weighted effects analysis revealed that bevacizumab had a pooled symptom improvement/stability rate of 86% (95% CI: 77-92%), pooled T2 imaging improvement/stability rate of 93% (95% CI: 87 -98%), and pooled T1-post contrast improvement/stability rate of 94% (95% CI: 87 – 98%). Subgroup analysis showed a statistically significant improvement favouring treatment with low-dose (below median, ≤7.5 mg/kg every 3 weeks) vs. high-dose bevacizumab with regards to symptom improvement/stability rate (P=0.02), but not for radiological T1 or T2 changes. The pooled T1-post contrast improvement/stability rate for LITT was 88% (95% CI 82 – 93%), and pooled symptom improvement/stability rate for surgery was 89% (95% CI 81 – 96%). Toxicity was inconsistently reported but was generally low for all treatment paradigms.
CONCLUSION: Corticosteroid-refractory RN that does not need urgent surgical intervention, with sufficient non-invasive diagnostic testing that favours RN, can be treated medically with bevacizumab in carefully selected patients as a strong recommendation. The role of LITT is evolving as a less invasive image-guided surgical modality, however, the overall evidence for each modality is of low quality. Prospective head-to-head comparisons are needed to evaluate the relative efficacy and toxicity profile amongst treatment approaches.
PMID:37482137 | DOI:10.1016/j.ijrobp.2023.07.015
