Deep-seated metastatic brain tumors

Introduction

Metastatic brain cancer is the most common type of brain tumor in adults, with an estimated 200,000 new cases each year in the United States alone. ^, The treatment options for patients with metastatic brain cancer include some combination of surgical resection, radiation therapy, and/or chemotherapy, in which the goal is to prevent local tumor progression. The majority of brain metastases occur at the gray-white junction, and as a result, most of these lesions are in close juxtaposition to the cortical surface. ^, When surgery is pursued for these typical lesions, the distance of traversed brain parenchyma is relatively short, and thus minimizes potential surgical morbidity. However, some metastases occur in deep-seated regions, such as the thalamus, basal ganglia, and deep cerebellar nuclei. Surgical resection of these deep-seated lesions is more challenging because of the morbidity associated with accessing and resecting these lesions. ^, In this chapter, we present a case of a deep-seated, basal ganglia metastatic brain tumor.

Example case

Chief complaint: headache

History of present illness

A 60-year-old, right-handed man with a history of hypertension, hypercholesterolemia, lung adenocarcinoma status post right upper lung lobectomy and radiation therapy 12 months prior who presented with worsening headaches. For the prior 3 weeks, he complained of worsening headaches, especially in the morning and with activity. He denied any weakness or any speaking problems ( Fig. 36.1 ).

Medications : Aspirin, lisinopril, atorvastatin.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension, hypercholesterolemia, lung adenocarcinoma status post right upper lung lobectomy 12 months prior.
Family history : No family of intracranial malignancies.
Social history: Military, remote smoking and no alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Language: slight dysarthria but intact naming and repetition; Cranial nerves II to XII intact; Right drift, moves all extremities with full strength.
Computed tomography chest/abdomen/pelvis : No evidence of systemic disease.

	Omar Arnaout, MD, Brigham and Women’s Hospital, Boston, MA, United States	Mohamed El-Fiki, MBBCh, MS, MD, University of Alexandria, Alexandria, Egypt	John S. Kuo, MD, PhD, University of Texas at Austin, Austin, TX, United States	Charles Teo, MBBS, University of New South Wales, Sydney, Australia
Preoperative
Additional tests requested	fMRI DTI CT chest, abdomen, pelvis	Oncology and radiation oncology evaluation MRS fMRI DTI PET	fMRI Wada (sodium amytal) test Neuropsychological assessment Radiation oncology evaluation	DTI
Surgical approach selected	Left fronto-temporal craniotomy	Left temporal awake craniotomy	Left fronto-temporal craniotomy	Left fronto-temporal craniotomy
Anatomic corridor	Left trans-Sylvian	Left trans-Sylvian	Left trans-Sylvian	Left trans-Sylvian, preservation of IFOF and CST
Goal of surgery	Diagnosis, relief of mass effect	Diagnosis, relief of mass effect	Diagnosis, relief of mass effect	GTR
Perioperative
Positioning	Left supine with 45- degree right head rotation	Left supine with right head rotation	Left supine with right head rotation	Left supine with right head rotation
Surgical equipment	Surgical navigation IOM Ultrasound	Surgical navigation Surgical microscope Ultrasonic aspirator	Surgical navigation Surgical microscope Ultrasound	Central line Surgical navigation Surgical microscope
Medications	Steroids Antiepileptics	Steroids Mannitol, furosemide Antiepileptics	Steroids Mannitol, furosemide Antiepileptics	Steroids Antiepileptic
Anatomic considerations	Frontal opercular speech centers, SLF/AF, insula, MCA branches and lenticulostriate	Speech centers, insular branches of MCA, left putamen, PCA, striatum, anterior capsule, amygdaloid body and tail, thalamus, commissural fibers of temporal lobe, uncus, superior peduncle	Sylvian fissure, MCA branches	Sylvian fissure, MCA and branches, temporal stem, IFOF, CST
Complications feared with approach chosen	Language dysfunction, injury to MCA branches and lenticulostriate	Expressive and mixed aphasia, right hemiparesis	Language deficits	Language dysfunction, visual field deficit, memory deficits, IFOF injury
Intraoperative
Anesthesia	General	Awake	General	General
Skin incision	Curvilinear	Linear	Curvilinear	Curvilinear behind hairline
Bone opening	Left fronto-temporal	Left fronto-temporal	Left fronto-temporal	Left fronto-temporal
Brain exposure	Left fronto-temporal	Left fronto-temporal	Left fronto-temporal	Left fronto-temporal
Method of resection	Pterional craniotomy exposing Sylvian fissure, drill sphenoid ridge flat, C-shaped dural opening, wide Sylvian fissure opening under microscopic visualization, entry point determined based on ultrasound and navigation avoiding and minimizing injury to white matter tracts and normal cortex, debulk tumor internally, dissect along brain-tumor interface, avoid hemostatic absorbable material to facilitate image interpretation	Left posterior temporal craniotomy based on navigation, open dura, microscopic trans-Sylvian dissection, transinsular transcortical to access lesion with monitoring according to tractography, open pia at depth of sulcus and avoid insular vessels, ultrasonic aspirator, piecemeal resection without fixed retractors, repetitive cortical and subcortical stimulation, dural closure, subgaleal drain	Left fronto-temporal craniotomy centered on Sylvian fissure and based on navigation, ultrasound to confirm lesion, dural opening with concurrent irrigation of antibiotic-impregnated irrigation, navigation to confirm trajectory through Sylvian fissure, open Sylvian fissure under microscopic visualization, biopsy specimen, decompress cyst with needle or syringe, ultrasound to confirm resection, watertight dural closure	Meticulous positioning with surgical trajectory perpendicular to floor to minimize need for retraction at the deepest portion of the tumor, keyhole craniotomy (<2 cm) over Sylvian fissure based on navigation, GTR with awareness of IFOF and CST, watertight dural closure
Complication avoidance	Trans-Sylvian approach, insular entry based on navigation and ultrasound, debulk tumor internally	Awake brain mapping, trans-Sylvian, avoid vessels, piecemeal resection with monitoring, avoiding retractors	Ultrasound to guide trajectory and resection, decompress cyst early	Keyhole craniotomy, Sylvian fissure openings, awareness of white matter tracts medially to the lesion
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Language dysfunction, arterial or venous infarction, residual tumor	Aphasia, increased motor weakness, cognitive dysfunction	Seizure, language dysfunction, failure to extubate	Progressive motor weakness, language dysfunction, seizures
Follow-up testing	MRI within 48 hours after surgery	CT within 24 hours after surgery MRI immediately after and 3 months after surgery	MRI within 24 hours after surgery	MRI within 24 hours after surgery
Follow-up visits	7–10 days after surgery	7 days after surgery and 2 weeks after starting radiation 1 month and every 3 months after surgery	2 weeks after surgery	6–8 weeks after surgery
Adjuvant therapies recommended	Consultation with medical and radiation oncology	Chemotherapy and radiation therapy	SRS to tumor bed, evaluation by oncology for chemotherapy	No radiation for GTR, SRS for STR