Stereotactic Radiosurgery for Choroid Plexus Tumors: A Report of the International Radiosurgery Research Foundation.

Background: Choroid plexus tumors (CPT) are rare epithelial tumors of the choroid plexus. Gross total resection (GTR) may be curative, but it is not always possible.

Objective: To evaluate the role of Gamma Knife stereotactic radiosurgery (GKSRS) as either a primary or adjuvant management option for WHO grade I-III CPT through a multicenter project.

Methods: A total of 32 patients (20 females) with a total of 43 treated tumors were included in the analysis. A total of 25 patients (78%) had undergone initial surgical resection. The median total tumor volume was 2.2 cc, and the median margin and maximum doses were 13 and 25.5 Gy, respectively.

Results: Local tumor control was achieved in 69% of cases. Local tumor progression-free survival (PFS) rate for low-grade tumors at 1, 3, and 5 yr was 90%, 77%, 58%, respectively. The actuarial local tumor PFS rate for high-grade tumors at 1, 3, and 5 yr was 77%, 62%, and 62%, respectively. There was no significant difference in local tumor control rates between low- and high-grade CPT (P = .3). Gender, age, and degree of resection were not associated with treated tumor PFS. Distant intracranial spread developed in 6 patients at a median of 22 mo after initial SRS. Actuarial distant brain tumor PFS rate at 1, 2, 5, and 10 yr was 93%, 88%, 78%, and 65%, respectively. Three patients (9%) developed persistent symptomatic adverse radiation effects at a median of 11 mo after the procedure.

Conclusion: GKSRS represents a minimally invasive alternative management strategy for imaging defined or surgically recurrent low- and high-grade CPT.