The butterfly effect on glioblastoma: is volumetric extent of resection more effective than biopsy for these tumors?

Abstract

A subset of patients with glioblastoma (GBM) have butterfly GBM (bGBM) that involve both cerebral hemispheres by crossing the corpus callosum. The prognoses, as well as the effectiveness of surgery and adjuvant therapy, are unclear because studies are few and limited. The goals of this study were to: (1) determine if bGBM have worse outcomes than patients with non-bGBM, (2) determine if surgery is more effective than biopsy, and (3) identify factors independently associated with improved outcomes for these patients. Adult patients who underwent surgery for a newly diagnosed primary GBM at an academic tertiary-care institution between 2007 and 2012 were retrospectively reviewed and tumors were volumetrically measured. Of the 336 patients with newly diagnosed GBM who were operated on, 48 (14 %) presented with bGBM, where 29 (60 %) and 19 (40 %) underwent surgical resection and biopsy, respectively. In multivariate analysis, a bGBM was independently associated with poorer survival [HR (95 % CI) 1.848 (1.250–2.685), p < 0.003]. In matched- pair analysis, patients who underwent surgical resection had improved median survival than biopsy patients (7.0 vs. 3.5 months, p = 0.03). In multivariate analysis, increasing percent resection [HR (95 % CI) 0.987 (0.977–0.997), p = 0.01], radiation [HR (95 % CI) 0.431 (0.225–0.812), p = 0.009], and temozolomide [HR (95 % CI) 0.413 (0.212–0. 784), p = 0.007] were each independently associated with prolonged survival among patients with bGBM. This present study shows that while patients with bGBM have poorer prognoses compared to non-bGBM, these patients can also benefit from aggressive treatments including debulking surgery, maximal safe surgical resection, temozolomide chemotherapy, and radiation therapy.

Laser interstitial thermal therapy for newly diagnosed and recurrent glioblastoma

“…Tumor size has previously been shown to affect ablation effectiveness. In 1 multiinstitutional study of LITT for highgrade gliomas, tumor volume > 10 cm 3 was associated with worse PFS outcomes, even with good ablation coverage. 16 Two of the responders in our study were receiving CCNU in the postoperative period when disease shrinkage was seen.…”

“…Patients with butterfly GBMs have a worse survival prognosis, with a median survival of only 3.5 months after biopsy and, for those who can undergo surgery, 5.1 months. 3 At our institution, we usually perform surgery for eccentric corpus callosum GBMs associated with mass effect, but for those with more symmetrical disease and extensive invasive disease, we refrain from resection. The patients in this series therefore tended to be in this latter group.…”

“…Patients who demonstrated an objective decrease in the volume of contrast-enhancing tumor in each MRI session from the first postoperative study to 6 months postprocedure and who had no evidence of clinical progression were designated "responders." For recurrent GBM cases, the National Institutes of Health (NIH) Recurrent GBM Scale score was calculated, with 1 point each for KPS score of ≤ 80, tumor size ≥ 50 cm 3 , and involvement of ≥ 2 eloquent regions of the brain.…”

“…Two patients had previously undergone craniotomy within 1 month of LITT, with extirpation of "resectable" portions of the tumor. The mean preoperative volume was 22.4 cm 3 . Successful ablative coverage of the entire contrastenhancing target was estimated to have been achieved in 4 of 8 cases at the time of the procedure.…”

Prognostic Implications of Extent of Resection in Glioblastoma: Analysis from a Large Database

“…10,[14][15][16] The majority demonstrate improved local control and OS with GTR. In a recent systematic review and meta-analysis, Brown et al visually evaluated the published Kaplan-Meier curves of 37 published studies on this topic.…”