Stereotactic Radiosurgery for Pineal and Related Tumors

Abstract

Radiosurgery is increasingly being used to treat pineal region tumors, either as an additional therapy after conventional treatments or as a primary treatment. We report our experience with Gamma Knife radiosurgery (GKRS) for the treatment of pineal and related tumors. Forty-nine patients underwent GKRS for pineal and related tumors (n = 74) between February 1992 and September 2007. The diagnosis was germ cell tumors (GCTs) in 38 patients (53 tumors), pineal parenchymal tumors (PPTs) in 9 (19 tumors), and unknown in 2 (2 tumors). The mean treatment volume was 3.3 ml (range 0.1-22 ml) in GCT cases and 3.7 ml (range 0.3-23 ml) in PPT cases. Prescribed doses around 50% isodose line ranged from 9.9 to 25.7 Gy. One patient (one tumor) with pineocytoma was lost to follow-up. Median clinical and imaging follow-up in the remaining 48 cases was 33.5 months (range, 3-192 months). Survival rates at 5 years and 10 years after GKRS in GCT cases (n = 38) were both 68%. They were 100 and 67%, respectively, in PPT cases (n = 8). We evaluated the treatment results with categorization of GCT cases into 2 groups, i.e. germinoma (group 1), and germinoma with syncytiotrophoblastic giant cell and malignant GCT (group 2). PPT cases were also divided into 2 groups, i.e. pineocytoma (group 3) and pineoblastoma and mixed pineocytoma/pineoblastoma (group 4). Local tumor control (LTC) rates at 3 and 5 years were 82% in group 1 (n = 18), 72 and 62% in group 2 (n = 35), and 85% in group 3 (n = 13). LTC rate at 2 years was 30% in group 4 (n = 5). In group 1 (n = 16), progression-free survival (PFS) rates at 3 and 5 years were 79 and 63%. They were 43 and 37% in group 2 (n = 22), and 80% in group 3 (n = 5). PFS rate at 2 years was 33% in group 4 (n = 3). Germinoma and pineocytoma showed higher LTC and PFS rates after GKRS, though pineoblastoma was liable to relapse. Intermediate prognosis was obtained in germinoma with syncytiotrophoblastic giant cell and malignant GCT. GKRS is expected to be an effective and safe adjuvant treatment approach to pineal and related tumors.

Gamma knife surgery for pineal region tumors: an alternative strategy for negative pathology

“…The male:female ratio in our patients was 15:2, which suggests that radiosensitive PRTs may have accounted for the majority of cases. According to this cha racteristic and preoperative imaging evaluations, we selected midrange doses for GKS compared to previous studies 20,23 . Another factor was the minimal invasiveness of GKS.…”

Endoscopic Third Ventriculostomy and CyberKnife Radiosurgery of a Pineal Parenchymal Tumor of Intermediate Differentiation

“…SRS has also been described for pineal region tumors and PPTs specifically. Gamma Knife radiosurgery, which involves the application of a skull mounted frame to achieve stereotaxis, has been shown to be particularly effective in controlling the growth of low-grade pineocytomas with reported rates of local tumor control of 85 to 100% [9,13]. Tumor control rates for the more aggressive PPTIDs and pineoblastomas was reported to be about 30% in one series [13].…”

Gamma Knife Radiosurgery in the Management of Unusual Grade I/II Primitive Neuroepithelial Tumours of the Brain

“…Sarkar (Sarkar et al, 2002) and Kano (Kano et al, 2009c) reported two GKRS studies on 18 and 30 patients affected with oligodendrogliomas and mixed oligodendroastrocytomas, respectively, but both series included low-and high-grade tumors. As concerns the unusual primitive neuroepithelial tumors of the brain, the largest published series always comprised low-and high-grade tumors (Kano et al, 2009d, Mori et al, 2009, Lekovic et al, 2007, Hasegawa et al, 2002, Kobayashi et al, 2001, while the studies with exclusively unusual LGPNTs were always represented by a few cases (usually, less than 15). To our knowledge, the work of our team represent the largest series of unusual LGPNTs treated with stereotactic radiosurgery.…”

“…As concerns outcome results ( ranged between 87.5% and 100%. Mori (Mori et al, 2009) is the only author who reported a 10-year actuarial survival rate of 67%. In our series, the 10-year actuarial survival rate was 92%.…”

“…The local TGC and PFS were excellent in all published studies. Among 5 cases with a median follow-up of 33.5 months, Mori (Mori et al, 2009) reported that the tumors were controlled in 4 cases. Only one patient developed cerebrospinal fluid dissemination after GKRS.…”