Upfront Stereotactic Radiosurgery for Pineal Parenchymal Tumors in Adults

Abstract

ObjectivePineal parenchymal tumors (PPTs) in adults are rare, and knowledge regarding their optimal management and treatment outcome is limited. Herein, we present the clinical results of our series of PPTs other than pineoblastomas managed by stereotactic radiosurgery (SRS) at upfront setting.MethodsBetween 1997 and 2014, nine consecutive adult patients with the diagnosis of PPTs, either pineocytoma or pineal parenchymal tumor of intermediate differentiation, were treated with SRS. There were 6 men and 3 women. The median age was 39 years (range, 31-53 years). All of the patients presented with symptoms of hydrocephalus. Endoscopic third ventriculostomy and biopsy was done for initial management. After histologic diagnosis, patients were treated with Gamma Knife with the mean dose of 13.3 Gy (n=3) or fractionated Cyberknife with 32 Gy (n=6).ResultsAfter a mean follow-up of 78.6 months (range, 14-223 months), all patients were alive and all of their tumors were locally controlled except for one instance of cerebrospinal fluid seeding metastasis. On magnetic resonance images, tumor size decreased in all patients, resulting in complete response in 3 patients and partial response in 6. One patient had experienced temporary memory impairment after SRS, which improved spontaneously.ConclusionSRS is effective and safe for PPTs in adults and can be considered as a useful alternative to surgical resection at upfront setting.

Role of Hypofractionated Stereotactic Radiosurgery in Recurrent Pineal Parenchymal Tumors of Intermediate Differentiation: A Case Report and Review of the Literature

“…The most commonly used fractionation scheme was 30 Gy in five daily fractions, but 36 Gy in five daily fractions was used in two patients. Only one patient who received 36 Gy in five daily fractions developed temporary memory impairment [13]. Iorio-Morin et al reported a new onset of Parinaud's syndrome, a new focal neurological deficit, and a worsening of hydrocephalus in their GK series [15].…”

“…SRS has been reported as safe and effective in treating PPTs [8][9][10][11][12][13][14]. Most of the studies in the literature are about SRS with the Gamma Knife (Elekta, Stockholm, Sweden).…”

“…Since PPID is seen uncommonly, the data about the treatment of the recurrent disease is also controversial. There are a few reports about the treatment of primary disease with GK and CK [ 8 , 10 , 13 - 15 ]. However, only Iorio-Morin et al reported that SRS with GK was used for three cases with recurrent PPID, and SRS doses were not specified [ 15 ].…”

Two-Session Radiosurgery for Large Primary Tumors Affecting the Brain

“…Current dose recommendations for single-session radiosurgery by multiple series for primary brain tumors hovers around 15 Gy for most series [17][18][19][20][21][22]. As the allowable value depends on tumor volume or the organs at risk abutting the lesion, this is not always possible.…”

“…Open surgery can be associated with a risk of neurological deficit, and residuals usually warrant further treatment with radiation [12][13][14][15][16]. Radiosurgery has been an alternative to treat small tumor volumes with usual marginal dose prescriptions around 15 Gy for the treatment of pineal or other primary tumors in the brain; many studies report different local tumor control and survival [17][18][19][20][21][22]. In large tumors of the hypothalamus or in the pineal region that deform sensitive structures such as the visual pathway, thalamus, and brainstem, covering the lesion with the usual recommended dose can be difficult since the prescription dose is higher than the recommended tolerance levels of the OARs.…”