The role of postoperative radiotherapy for the treatment of gangliogliomas

Abstract

BACKGROUND: Because of their rarity, no prospective studies have been performed regarding gangliogliomas. The optimal treatment regimen is unclear. In this study, the authors compared 4 therapies for local control (LC) and overall survival (OS) in patients with ganglioglioma. METHODS: In 402 patients with ganglioglioma, outcomes were compared for patients who underwent gross total resection alone (GTR) (n ¼ 188), GTR plus radiotherapy (GTR þ RT) (n ¼ 21), subtotal resection alone (STR) (n ¼ 113), and STR plus RT (STR þ RT (n ¼ 80). Age, sex, tumor site, and histologic grade also were investigated. Subgroup analyses were performed for both low-grade and high-grade tumors. RESULTS: The 10-year LC rates were 89% after GTR, 90% after GTR þ RT, 52% after STR, and 65% after STR þ RT (P < .001); and the 10-year OS rates were 95%, 95%, 62%, and 74%, respectively (P < .001). After STR, irradiation significantly improved LC (P ¼ .004) but not OS (P ¼ .22). After GTR, irradiation did not significantly improve LC (P ¼ .23) or OS (P ¼ .29). On multivariate analyses, LC and OS were associated with therapy and pathologic grade, and OS also was associated with tumor site. In low-grade tumors, STR þ RT resulted in better LC (P ¼ .016) but not better OS (P ¼ .18); and, after GTR, LC (P ¼ .28) and OS (P ¼ 1.0) were not improved with postoperative radiotherapy. In highgrade tumors, STR þ RT resulted in better LC (P ¼ .016) but not better OS (P ¼ .41); after GTR, LC (P ¼ .56) and OS (P ¼ .61) were not improved with irradiation. CONCLUSIONS: According to this review, GTR should be performed whenever safely possible and does not require postoperative irradiation. If only STR is achieved, then RT improves LC of both low-grade and high-grade tumors and, thus, should be considered seriously. Cancer 2010;116:432-42.

Pediatric Primary Anaplastic Ganglioglioma: A Case Report and Review of the Literature

“…Doses greater than 50 Gy are frequently recommended for local control [15,20]. Prescribed doses for pediatric AGGs ranged between 50 and 63 Gy, but Rades et al [[8]] found that dose escalation beyond 54 Gy did not improve local control. …”

“…The extent of surgery is related to the prognosis, gross total resection being a predictor of favorable outcome with respect to both LC [3,8] and OS [6,8]. Some authors have stated that cell kinetic studies, such as MIB-1 staining, may be useful for predicting the prognosis [10,29].…”

“…Rades et al [8] found that pathologic grade was associated significantly with both local control (LC; p < 0.001) and overall survival (OS; p < 0.001) in a large retrospective series including 342 patients with GGs and 60 cases of AGGs.…”

“…According to Rades et al [8], the criteria for high-grade tumors are the presence of anaplastic histologic features or the presence of an MIB-1 labeling index >10%. More frequently, the malignant characteristics are featured by the glial component, but cases where both the astrocytic and ganglionic populations are malignant, as in the case described here, have previously been reported[9,10,11,12,13,14].…”

Bilateral Optic Pathway Ganglioglioma: The Fifth Case in the Literature

“…Although there is a debate on appropriate adjuvant treatment protocols, radiation appears to improve local tumor control (65% in radiated patients vs. 52% in patients with subtotal resection alone) for optic gangliogliomas and overall survival in low-grade tumors [34]. However, physicians must be aware of malignant transformation risk of gangliogliomas after radiation [35].…”