Combined high-field intraoperative magnetic resonance imaging and endoscopy increase extent of resection and progression-free survival for pituitary adenomas

Abstract

Purpose The clinical benefit of combined intraoperative magnetic resonance imaging (iMRI) and endoscopy for transsphenoidal pituitary adenoma resection has not been completely characterized. This study assessed the impact of microscopy, endoscopy, and/or iMRI on progression-free survival, extent of resection status (gross-, near-, and subtotal resection), and operative complications. Methods Retrospective analyses were performed on 446 transsphenoidal pituitary adenoma surgeries at a single institution between 1998 and 2012. Multivariate analyses were used to control for baseline characteristics, differences during extent of resection status, and progression-free survival analysis. Results Additional surgery was performed after iMRI in 56/156 cases (35.9 %), which led to increased extent of resection status in 15/156 cases (9.6 %). Multivariate ordinal logistic regression revealed no increase in extent of resection status following iMRI or endoscopy alone; however, combining these modalities increased extent of resection status (odds ratio 2.05, 95 % CI 1.21–3.46) compared to conventional transsphenoidal microsurgery. Multivariate Cox regression revealed that reduced extent of resection status shortened progression-free survival for near- versus gross-total resection [hazard ratio (HR) 2.87, 95 % CI 1.24–6.65] and sub- versus near-total resection (HR 2.10; 95 % CI 1.00–4.40). Complication comparisons between microscopy, endoscopy, and iMRI revealed increased perioperative deaths for endoscopy versus microscopy (4/209 and 0/237, respectively), but this difference was non-significant considering multiple post hoc comparisons (Fisher exact, p = 0.24). Conclusions Combined use of endoscopy and iMRI increased pituitary adenoma extent of resection status compared to conventional transsphenoidal microsurgery, and increased extent of resection status was associated with longer progression-free survival. Treatment modality combination did not significantly impact complication rate.

Pituitary surgery and volumetric assessment of extent of resection: a paradigm shift in the use of intraoperative magnetic resonance imaging

“…Contrastenhanced intraoperative MRI (iMRI), first introduced by Black et al in 1994,6 has been increasingly used in pituitary surgery based on the assumption that it would improve GTR rates. 14,17,21,33,34,36,37,41,47,48 Moreover, it has been stated that iMRI may be helpful even in patients in whom GTR is not feasible. 34 In these patients, iMRI could still help to extend the tumor resection beyond the capabilities of microsurgical or endoscopic techniques alone.…”

iMRI During Transsphenoidal Surgery

“…Two large studies that comprised endoscopic and microscopic TSS cohorts, did not examine the differences in rates of unexpected tumor residuals between the two approaches. 41,63 Recent studies confirm the utility of iMRI in detecting actionable unexpected tumor residuals even in endoscopic TSS procedures. 58,64 …”

“…However, implementation of either iMRI or endoscopy alone did not significantly affect biochemical remission rates (p = 0.93). 63 …”

White Paper: Interventional MRI: Current Status and Potential for Development Considering Economic Perspectives, Part 1: General Application

“…Intraoperative MRI can be used to generate current data for navigation [82] so that the tumor tissue can be removed as completely as possible and eloquent areas of the brain can be protected to the greatest extent possible [83]. In connection with neurosurgical instruments or with the fixed endoscope that is used in neurosurgery in some cases, the benefit can be further increased [84]. In neurosurgical interventions, interventional MRI facilitates the locating of target regions and the removal of tumors that is as complete as possible with the fewest possible side effects.…”