Gamma Knife surgery for craniopharyngioma: report on a 20-year experience

Abstract

ObjectAlthough craniopharyngiomas are benign intracranial tumors, their high recurrence rates and intimate associations with surrounding neurovascular structures make gross tumor resection challenging. Stereotactic radiosurgery has been introduced as a valuable adjuvant therapy for recurrent or residual craniopharyngiomas. However, studies with large patient populations documenting long-term survival and progression-free survival rates are rare in the literature. The current study aims to report the long-term radiosurgical results and to define the prognostic factors in a large cohort of patients with a craniopharyngioma.MethodsA total of 137 consecutive patients who underwent 162 sessions of Gamma Knife surgery (GKS) treatments at the Taipei Veterans General Hospital between 1993 and 2012 were analyzed. The patients' median age was 30.1 years (range 1.5–84.9 years), and the median tumor volume was 5.5 ml (range 0.2–28.4 ml). There were 23 solid (16.8%), 23 cystic (16.8%), and 91 mixed solid and cystic (66.4%) craniopharyngiomas. GKS was indicated for residual or recurrent craniopharyngiomas. The median radiation dose was 12 Gy (range 9.5–16.0 Gy) at a median isodose line of 55% (range 50%–78%).ResultsAt a median imaging follow-up of 45.7 months after GKS, the rates of tumor control were 72.7%, 73.9%, and 66.3% for the solid, cystic, and mixed tumors, respectively. The actuarial progression-free survival rates plotted by the Kaplan-Meier method were 70.0% and 43.8% at 5 and 10 years after radiosurgery, respectively. After repeated GKS, the actuarial progression-free survival rates were increased to 77.3% and 61.2% at 5 and 10 years, respectively. The overall survival rates were 91.5% and 83.9% at the 5- and 10-year follow-ups, respectively. Successful GKS treatment can be predicted by tumor volume (p = 0.011). Among the 137 patients who had clinical follow-up, new-onset or worsened pituitary deficiencies were detected in 11 patients (8.0%). Two patients without tumor growth had a worsened visual field, and 1 patient had a new onset of third cranial nerve palsy.ConclusionsThe current study suggests that GKS is a relatively safe modality for the treatment of recurrent or residual craniopharyngiomas, and it is associated with improved tumor control and reduced in-field recurrence rates. Acceptable rates of complications occurred.

Neuroendoscopy Followed by Radiotherapy in Cystic Craniopharyngiomas—a Long-Term Follow-Up

“…With respect to endocrine outcomes, new endocrinopathies have been observed in 6.1-90% of the cases after any surgical and/or radiation therapy for craniopharyngiomas (Table 4) (6,12,16,18,21,24,33,40). Accurate rates for developing new endocrinopathy have not been reported in patients treated with neuroendoscopy followed by radiotherapy.…”

Radiosurgery for Pediatric Brain Tumors

“…Of note, the definition of control varies across institutions as not all authors had details regarding tumor cyst growth and so forth. From the largest series (137 patients), at last follow‐up, 53.9% of patients had tumor shrinkage, 1.6% stable tumor, 16.4% had tumor growth, 14.8% had initial tumor shrinkage followed by delayed growth, 4.7% had new lesions outside the radiosurgery field, and 8.6% had cyst enlargement …”

“…had no reported visual pathway deficits, but this series had a shorter follow‐up of 24 months. As detailed in Table , the incidence of long‐term visual complications using single‐session SRS for craniopharyngioma has been reported at 0–8% …”

“…Hypothalamic‐pituitary dysfunction can be a long‐term side effect of both fractionated radiotherapy and radiosurgery for craniopharyngioma. Most patients have endocrine deficits prior to radiotherapy related to surgery or the tumor itself, with the largest SRS series reporting up to 86% endocrine deficiencies prior to radiotherapy . The larger series with adequate follow‐up report a low incidence of SRS‐related endocrine deficiencies ranging from 2% to 8% …”

“…The available data come from series that include both pediatric and adult patients. [64][65][66][67][68][69][70][71][72][73][74][75] The location of these tumors in proximity to the optic apparatus has limited the role of radiosurgery for these tumors. However, these tumors otherwise make ideal radiosurgery targets in that they are often welldefined contrast enhancing lesions with low likelihood of CNS dissemination.…”