Successful application of stereotactic radiosurgery for multiply recurrent Rathke's cleft cysts

Stereotactic radiosurgery for Rathke's cleft cysts: an international multicenter study

OBJECTIVE

Rathke's cleft cysts (RCCs) are sellar collections from an incompletely regressed Rathke's pouch. Common symptoms of RCCs can include headaches, visual loss, and endocrinopathy. Surgery is required in some cases of symptomatic or growing RCCs. Recurrence after surgery is common (range 10%-40%). Stereotactic radiosurgery (SRS) has been used in an attempt to control growth and symptoms, but outcomes are not well known. The authors sought to study the outcomes of RCCs following Gamma Knife surgery for both salvage and initial treatment.

METHODS

The outcomes of 25 patients with RCCs who underwent SRS between 2001 and 2020 were reviewed. Four patients received initial SRS and 21 were treated with salvage SRS. Diagnosis was based on imaging or histopathology. Cyst control was defined as stability or regression of the cyst. Kaplan-Meier analysis was used to determine time to recurrence and determine potential factors for recurrence.

RESULTS

The respective median clinical follow-up and margin dose were 6.5 years and 12 Gy. Overall control was achieved in 19 (76%) of 25 patients, and 4 recurrences required further intervention. The average time to recurrence was 35.6 months in those RCCs that recurred. Visual recovery occurred in 14 (93.3%) of 15 patients and no new post-SRS visual deficits occurred. The presence of a pretreatment visual deficit was often an indicator of RCC regrowth. All 3 patients with pretreatment hyperprolactinemia experienced resolution after SRS. New endocrinopathy related to SRS was noted in 5 (20%) of 25 patients, all of which were thyroid and/or cortisol axis related. Upfront SRS was used in 4 patients. No new endocrinopathies or visual deficits developed after upfront SRS, and the 1 patient with a pretreatment visual deficit recovered. One of the 4 patients with upfront SRS experienced a recurrence after 7.5 years.

CONCLUSIONS

SRS produced effective recovery of visual deficits and carries a low risk for new visual deficits. Cyst control was achieved in approximately three-fourths of the patients. Following SRS, patients without pretreatment visual deficits are less likely to have RCC regrowth. Endocrinopathy can occur after SRS, similar to other sellar mass lesions. Initial SRS shows the potential for long-term cyst control, with improvement of symptoms and a low risk for complications.

Pituitary Surgery

Surgery, more specifically transsphenoidal approach, remains the primary treatment chosen for the majority of pituitary tumors (except for prolactinomas where medical treatment is indicated) allowing for pathologic analysis and complete or partial tumor removal. Transcranial approaches, employing craniotomies, are still needed in some patients with giant pituitary adenomas and in many of those harboring craniopharyngiomas. However, the surgical treatment of pituitary tumors is challenging because of their complex anatomical location and their heterogenous histology. Due to the proximity of critical structures, a successful surgical procedure may often not be achievable due to the high risks related to the procedure itself. Therefore, the treatment of pituitary tumors in 2020 commonly requires a multimodal approach, including surgery, radiosurgery, radiation therapy, and medical therapy. Recently, efforts have been made to develop intraoperative imaging, by increasing the diffusion of radiosurgery. Furthermore, the development of Pituitary Tumor Centers of Excellence (PTCOE) is becoming crucial to provide the optimal treatment for a single patient. There is in fact sufficient evidence that the best and optimal outcome in terms of tumor resection and correction of hormonal over secretion as well as the lowest rate of complications are obtained in centers of excellence with sufficiently experienced, specialized surgeons and a high patient load. Technological developments will probably even gain increasing importance in the future.