- Email: [email protected]
Image-Guided Maximal Resection of Intrinsic Tumors
Accepted Manuscript Image-guided maximal resection of intrinsic tumors Wenya Linda Bi, MD, PhD E. Antonio Chiocca, MD, PhD PII:
S1878-8750(14)00454-9
DOI:
10.1016/j.wneu.2014.04.070
Reference:
WNEU 2350
To appear in:
World Neurosurgery
Received Date: 7 March 2014 Accepted Date: 30 April 2014
Please cite this article as: Bi WL, Chiocca EA, Image-guided maximal resection of intrinsic tumors, World Neurosurgery (2014), doi: 10.1016/j.wneu.2014.04.070. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Image-guided maximal resection of intrinsic tumors Wenya Linda Bi, MD, PhD; E. Antonio Chiocca, MD, PhD
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Please send correspondence to: E. Antonio Chiocca, MD, PhD Brigham and Women’s Hospital Department of Neurosurgery 15 Francis Street, PBB-3 Boston, MA 02115 Phone: 617-732-6939 Fax: 617-734-8342 Email: [email protected]
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Department of Neurosurgery, Harvard Medical School, Brigham and Women’s Hospital, Boston, MA Center for Neuro-oncology, Dana-Farber Cancer Institute, Boston, MA
ACCEPTED MANUSCRIPT
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The importance of extent of resection has been demonstrated in a number of welldevised studies for both extrinsic and intrinsic tumors. From the Simpson grading of meningioma resection to the impact of resection in both primary and recurrent glioblastomas, there is little argument that a universal goal of tumor surgery is maximal lesion removal as permitted by preservation of post-operative neurologic function.1,2 However, as Orringer et al. demonstrated, surgeons often over-estimate the perceived extent of tumor resection.3 As such, adjunctive modalities including intra-operative imaging and improved real-time detection of tumor margins are increasingly integrated with traditional surgical strategies. Livne et al. report their experience with low-field intraoperative MRI for intra-axial lesions over a 12-year period, which interestingly account for less than 40% of all intraoperative MRI (iMRI) cases at the authors’ institution4. This seems to provide practical evidence not only of the wide applicability of iMRI technology, but also of the presumably acceptable cost for standard utilization of this resource. Intra-axial lesions resected with the aid of iMRI included an expected range of high-grade and low-grade gliomas, as well as metastases and cavernomas, with half of the lesions located in eloquent areas and a third of the lesions being non-enhancing. Livne et al. found a correlation between eloquent location and absence of contrast enhancement with incomplete resection. Amongst patients in whom the initial goal of surgery was total removal of lesion, complete resection was attained in 82%: in 43% of these iMRI was utilized to provide further resection. Interestingly, of the 53 patients in whom pre-operative surgical intent was incomplete resection, iMRI led to a similar rate of additional resection in 47% of cases and elicited complete resection beyond the initial goal of surgery in 1 case. Therefore, intra-operative imaging abetted achievement of the operative goal, whether this was intent for complete resection or for reaching a pre-determined boundary that would be limiting because of increased morbidity. Our institution has been privileged to experience first-hand the evolution of the first low-field (0.5 T) intraoperative MRI in 19975 to the current Advanced Multimodality Image-guided Operating suite (AMIGO) with integrated 3 T MRI, 3D ultrasound, PET/CT, and fluoroscopy capabilities. The merits of low-field iMRI are reflected by the pervasive adoption of iMRI suites at a large number of institutions in the modern era. MRIs with increasingly higher field strengths (up to 7 T in some academic centers) offer unique opportunities for detailed anatomic resolution, tractography, and research investigations. However, they also impose additional restrictions on compatible instruments, intraoperative neurophysiologic monitoring, and safety precautions. Access, iMRI operative room time allotment and staffing, and dedicated equipment calls for judicious resource utilization for cases that might be best served by immediate visual feedback of surgical results, including intra-axial neoplasms, suprasellar and parasellar lesions, and resection of seizure focus. The full potential of iMRI technology in advancing surgical technique, patient outcome, as well as research likely remains to be discovered. The pursuit of maximal resection for intrinsic lesions by Levine et al. is laudable, entailing up to 5-6 scans in specific circumstances, and 4 scans in 8.5% of cases. Impressively, this was achieved at the cost of only 28 minutes of scan time or 46 minutes of total surgery overhead time on average per case. As the authors suggest, focused selection of limited iMRI sequences depending on the pre-operative imaging characteristics of the lesion is imperative to overall surgical efficiency. Even for the maximal end of additional
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surgery overhead in the study, with close to 3 hours of added time, upfront investment of operative resources may be well worth the additional disease-free interval garnered for the patient. Often discussed within the realm of image-guidance, some argue that the art of neurosurgery calls for a mastery of anatomic localization with or without adjunctive tools. The correlate arises then, could the routine use of intra-operative MRI impede, or perhaps even diminish, achievable surgical results based on technique alone over time? The authors note that complete tumor resection was achieved in only 73% of metastasis resections, spanning a variety of pathologies including lung, breast, ovarian, melanoma, and renal cell carcinoma. Although excellent, this rate begs the question of whether even better results might be achieved for well-defined metastases, which are intrinsically different in boundaries compared to infiltrative intraparenchymal lesions. We have noted that even seasoned practitioners are at times surprised at the additional resection incurred after intra-operative imaging. One envisions that this tool might be even more beneficial to surgeons who are in the early phases of building up their technical repertoire or at institutions with a variable volume of intrinsic lesions. With respect to neoplastic lesions, while the benefits of physically diminishing tumor burden are increasingly embraced, closer inspection at the biologic variables that promote tumor recurrence and overall outcome often remains lacking. For example, is the primary driver of future recurrence for a pituitary macroadenoma a focus of cavernous sinus residual or the underlying molecular signature inherent to the tumor? The same quandary applies to the full gamut of intrinsic brain neoplasms. Staged resection, as inherent to iMRI-guided surgeries, also offers a unique platform for in-depth analysis of tumor core versus margins. As we continue to invest resources in optimizing our surgical craft and outcomes, we should integrate molecular studies with image-guidance technology. Only through such true multi-modality approach to intra-axial lesions can we expedite better understanding of the challenges facing our patients.
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References
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Sanai N, Polley MY, McDermott MW, Parsa AT, Berger MS. An extent of resection threshold for newly diagnosed glioblastomas. Journal of neurosurgery. Jul 2011;115(1):3-8. Bloch O, Han SJ, Cha S, et al. Impact of extent of resection for recurrent glioblastoma on overall survival: clinical article. Journal of neurosurgery. Dec 2012;117(6):10321038. Orringer D, Lau D, Khatri S, et al. Extent of resection in patients with glioblastoma: limiting factors, perception of resectability, and effect on survival. Journal of neurosurgery. Nov 2012;117(5):851-859. Livne O, Harhel R, Hadani M, Spiegelmann R, Feldman Z, Cohen ZR. Intraoperative magnetic resonance imaging for resection of intra-axial brain lesions. A decade of experience using low-field MRI, Polestar N-10, 20, 30 systems. World neurosurgery. Feb 8 2014. Black PM, Moriarty T, Alexander E, 3rd, et al. Development and implementation of intraoperative magnetic resonance imaging and its neurosurgical applications. Neurosurgery. Oct 1997;41(4):831-842; discussion 842-835.
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ACCEPTED MANUSCRIPT
S1878-8750(14)00454-9
DOI:
10.1016/j.wneu.2014.04.070
Reference:
WNEU 2350
To appear in:
World Neurosurgery
Received Date: 7 March 2014 Accepted Date: 30 April 2014
Please cite this article as: Bi WL, Chiocca EA, Image-guided maximal resection of intrinsic tumors, World Neurosurgery (2014), doi: 10.1016/j.wneu.2014.04.070. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT
Image-guided maximal resection of intrinsic tumors Wenya Linda Bi, MD, PhD; E. Antonio Chiocca, MD, PhD
AC C
EP
SC M AN U
TE D
Please send correspondence to: E. Antonio Chiocca, MD, PhD Brigham and Women’s Hospital Department of Neurosurgery 15 Francis Street, PBB-3 Boston, MA 02115 Phone: 617-732-6939 Fax: 617-734-8342 Email: [email protected]
RI PT
Department of Neurosurgery, Harvard Medical School, Brigham and Women’s Hospital, Boston, MA Center for Neuro-oncology, Dana-Farber Cancer Institute, Boston, MA
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
The importance of extent of resection has been demonstrated in a number of welldevised studies for both extrinsic and intrinsic tumors. From the Simpson grading of meningioma resection to the impact of resection in both primary and recurrent glioblastomas, there is little argument that a universal goal of tumor surgery is maximal lesion removal as permitted by preservation of post-operative neurologic function.1,2 However, as Orringer et al. demonstrated, surgeons often over-estimate the perceived extent of tumor resection.3 As such, adjunctive modalities including intra-operative imaging and improved real-time detection of tumor margins are increasingly integrated with traditional surgical strategies. Livne et al. report their experience with low-field intraoperative MRI for intra-axial lesions over a 12-year period, which interestingly account for less than 40% of all intraoperative MRI (iMRI) cases at the authors’ institution4. This seems to provide practical evidence not only of the wide applicability of iMRI technology, but also of the presumably acceptable cost for standard utilization of this resource. Intra-axial lesions resected with the aid of iMRI included an expected range of high-grade and low-grade gliomas, as well as metastases and cavernomas, with half of the lesions located in eloquent areas and a third of the lesions being non-enhancing. Livne et al. found a correlation between eloquent location and absence of contrast enhancement with incomplete resection. Amongst patients in whom the initial goal of surgery was total removal of lesion, complete resection was attained in 82%: in 43% of these iMRI was utilized to provide further resection. Interestingly, of the 53 patients in whom pre-operative surgical intent was incomplete resection, iMRI led to a similar rate of additional resection in 47% of cases and elicited complete resection beyond the initial goal of surgery in 1 case. Therefore, intra-operative imaging abetted achievement of the operative goal, whether this was intent for complete resection or for reaching a pre-determined boundary that would be limiting because of increased morbidity. Our institution has been privileged to experience first-hand the evolution of the first low-field (0.5 T) intraoperative MRI in 19975 to the current Advanced Multimodality Image-guided Operating suite (AMIGO) with integrated 3 T MRI, 3D ultrasound, PET/CT, and fluoroscopy capabilities. The merits of low-field iMRI are reflected by the pervasive adoption of iMRI suites at a large number of institutions in the modern era. MRIs with increasingly higher field strengths (up to 7 T in some academic centers) offer unique opportunities for detailed anatomic resolution, tractography, and research investigations. However, they also impose additional restrictions on compatible instruments, intraoperative neurophysiologic monitoring, and safety precautions. Access, iMRI operative room time allotment and staffing, and dedicated equipment calls for judicious resource utilization for cases that might be best served by immediate visual feedback of surgical results, including intra-axial neoplasms, suprasellar and parasellar lesions, and resection of seizure focus. The full potential of iMRI technology in advancing surgical technique, patient outcome, as well as research likely remains to be discovered. The pursuit of maximal resection for intrinsic lesions by Levine et al. is laudable, entailing up to 5-6 scans in specific circumstances, and 4 scans in 8.5% of cases. Impressively, this was achieved at the cost of only 28 minutes of scan time or 46 minutes of total surgery overhead time on average per case. As the authors suggest, focused selection of limited iMRI sequences depending on the pre-operative imaging characteristics of the lesion is imperative to overall surgical efficiency. Even for the maximal end of additional
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
surgery overhead in the study, with close to 3 hours of added time, upfront investment of operative resources may be well worth the additional disease-free interval garnered for the patient. Often discussed within the realm of image-guidance, some argue that the art of neurosurgery calls for a mastery of anatomic localization with or without adjunctive tools. The correlate arises then, could the routine use of intra-operative MRI impede, or perhaps even diminish, achievable surgical results based on technique alone over time? The authors note that complete tumor resection was achieved in only 73% of metastasis resections, spanning a variety of pathologies including lung, breast, ovarian, melanoma, and renal cell carcinoma. Although excellent, this rate begs the question of whether even better results might be achieved for well-defined metastases, which are intrinsically different in boundaries compared to infiltrative intraparenchymal lesions. We have noted that even seasoned practitioners are at times surprised at the additional resection incurred after intra-operative imaging. One envisions that this tool might be even more beneficial to surgeons who are in the early phases of building up their technical repertoire or at institutions with a variable volume of intrinsic lesions. With respect to neoplastic lesions, while the benefits of physically diminishing tumor burden are increasingly embraced, closer inspection at the biologic variables that promote tumor recurrence and overall outcome often remains lacking. For example, is the primary driver of future recurrence for a pituitary macroadenoma a focus of cavernous sinus residual or the underlying molecular signature inherent to the tumor? The same quandary applies to the full gamut of intrinsic brain neoplasms. Staged resection, as inherent to iMRI-guided surgeries, also offers a unique platform for in-depth analysis of tumor core versus margins. As we continue to invest resources in optimizing our surgical craft and outcomes, we should integrate molecular studies with image-guidance technology. Only through such true multi-modality approach to intra-axial lesions can we expedite better understanding of the challenges facing our patients.
ACCEPTED MANUSCRIPT
References
RI PT
SC
5.
M AN U
4.
TE D
3.
EP
2.
Sanai N, Polley MY, McDermott MW, Parsa AT, Berger MS. An extent of resection threshold for newly diagnosed glioblastomas. Journal of neurosurgery. Jul 2011;115(1):3-8. Bloch O, Han SJ, Cha S, et al. Impact of extent of resection for recurrent glioblastoma on overall survival: clinical article. Journal of neurosurgery. Dec 2012;117(6):10321038. Orringer D, Lau D, Khatri S, et al. Extent of resection in patients with glioblastoma: limiting factors, perception of resectability, and effect on survival. Journal of neurosurgery. Nov 2012;117(5):851-859. Livne O, Harhel R, Hadani M, Spiegelmann R, Feldman Z, Cohen ZR. Intraoperative magnetic resonance imaging for resection of intra-axial brain lesions. A decade of experience using low-field MRI, Polestar N-10, 20, 30 systems. World neurosurgery. Feb 8 2014. Black PM, Moriarty T, Alexander E, 3rd, et al. Development and implementation of intraoperative magnetic resonance imaging and its neurosurgical applications. Neurosurgery. Oct 1997;41(4):831-842; discussion 842-835.
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