RESUMO
BACKGROUND: A histiocytosis is a group of immunoproliferative disorders of clonal cells. The management protocols are still evolving, with chemotherapy as the mainstay of treatment. OBJECTIVE: This study aims to evaluate the feasibility, safety, efficacy, and complication profile of stereotactic radiosurgery for intracranial histiocytosis. METHODOLOGY: The authors reviewed PubMed, Scopus, Web of Science, and Embase for "radiosurgery" and "histiocytosis" in the English/Japanese language following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. The patient profile, radiosurgical parameters (dose and isodose), target volume, and mode of radiosurgery (Gamma knife, LINAC radiosurgery, etc.) were collected. Its use as primary or adjuvant therapy, clinical and radiological outcome was also evaluated. RESULTS: We identified 7 studies (9 patients); mean age: 41.9 years (24-57 years). Six patients received Gamma-knife radiosurgery, whereas 3 received CyberKnife radiosurgery. The Langerhans cell histiocytosis variants were eosinophilic granuloma in 3, whereas 4 were not defined. Two cases had Rosai-Dorfman disease, and 2 different yet pathogenetically related histiocytic disorders. Four patients harbored lesions in the pituitary stalk and posterior pituitary, 2 patients in the petrous region, 1 patient had a pontine lesion, and 2 patients had multiple lesions. The dose delivered ranged from 8 to 28 Gy. A total of 18 lesions (9 patients) were followed for 81.67 patient-years: 7 (39%) disappeared, 8 (44.4%) showed radiological reduction, and 2 (11%) remained stable. One lesion (5%) showed an increase in size needed surgical excision. There were no adverse effects. CONCLUSION: The role of stereotactic radiosurgery needs to be further evaluated as the current cohort with only 9 cases (2 are Rosai-Dorfman disease) is insufficient to make conclusions. It may be a viable alternative in localized disease, along with chemotherapy and targeted surgery.
