Multiple accessible metastatic brain tumors

Introduction

The most common type of brain tumor in adults is metastatic brain tumors, with an incidence of 3 to 14 per 100,000 people per year. ^, Surgical resection is generally offered to patients with solitary, large, symptomatic lesions who have good prognoses, which is dependent on age, functional status, primary tumor control, and presence of extracranial disease. However, a significant number of patients present with multiple metastatic brain tumors. These lesions can sometimes all be accessible for surgical resection, whereas other times only a select few. In this chapter, we present a case of a patient with multiple metastatic brain lesions that are all relatively accessible.

Example case

Chief complaint: imbalance

History of present illness

A 47-year-old, right-handed man with a history of hypertension and lung adenocarcinoma status post resection and radiation therapy 2 years prior presented with imbalance over several weeks. He underwent resection of a lung adenocarcinoma followed by radiation for localized disease. He had been well but had increasing difficulty with balance in which he felt as though he was intoxicated over the past 3 to 4 weeks. He denies headaches, nausea, vomiting, or weakness ( Fig. 34.1 ).

Medications : Lisinopril.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension, lung adenocarcinoma status postresection 2 years prior.
Family history : No history of intracranial malignancies.
Social history: Mail delivery worker, remote smoking history, no alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Language: intact naming and repetition; Cranial nerve II to XII intact; No drift, moves all extremities with full strength; Cerebellar: truncal ataxia and bilateral finger-to-nose dysmetria.
Computed tomography chest/abdomen/pelvis : No evidence of systemic disease.

	Lucas Alverne Freitas de Albuquerque, MD, Hospital Geral de Fortaleza, Ceara, Brazil	Francesco DiMeco, MD, Massimiliano Del Bene, MD, Carlo Besta Neurological Institute, Milan, Italy	Fredric B. Meyer, MD, Mayo Clinic, Rochester, MN, United States	Robert E. Wharen, MD, Mayo Clinic, Jacksonville, FL, United States
Preoperative
Additional tests requested	Anesthesiology evaluation Palliative care evaluation Psychological evaluation	Transcranial doppler ultrasound with micro bubbles to assess for right-to-left cardiac shunt	Oncology evaluation	Radiation oncology evaluation Oncology evaluation
Surgical approach selected	Midline suboccipital craniotomy	Median/right paramedial suboccipital craniotomy in sitting position	Midline suboccipital craniotomy	Preoperative SRS to right perirolandic lesion and right suboccipital craniectomy for cerebellar lesion
Anatomic corridor	Cerebellar vermis	Cerebellar hemisphere	Cerebellar vermis	Cerebellar hemisphere
Goal of surgery	Improve overall survival, avoid hydrocephalus	Complete resection with 5-mm margins, preserve CSF pathways	Complete resection of cerebellar tumor, decompression of fourth ventricle	Relief of posterior fossa mass effect
Perioperative
Positioning	Prone Concorde, no pins	Semisitting, neutral	Prone neutral	Right supine
Surgical equipment	Surgical microscope	Precordial Doppler Central catheter Surgical navigation Surgical microscope Chisel Ultrasound Ultrasonic aspirator	Surgical microscope +/– Ultrasound +/– Ultrasonic aspirator	Surgical navigation Surgical microscope
Medications	Steroids Hypertonic saline	Steroids, high fluids	Steroids	Steroids +/– Mannitol
Anatomic considerations	Cerebellar vermis, dentate nucleus	Suboccipital muscles, occipital/transverse/torcular sinuses, cerebellar hemispheres, vermis, tentorium, cisterna magna, cerebellar draining veins	Transverse sinus, torcula, fourth ventricular floor, middle cerebellar peduncle	Cerebellar hemisphere Shortest working distance
Complications feared with approach chosen	Akinetic mutism, hydrocephalus	Venous air embolism, hydrocephalus, venous engorgement, CSF leak, posterior fossa syndrome	Cerebellar edema, wound healing issues, cerebellar mutism	Injury to cerebellum, hydrocephalus
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Midline linear	Midline linear	Midline linear from inion to C2	Linear paramedian
Bone opening	Midline suboccipital	Median/right paramedial suboccipital	Midline suboccipital	Right suboccipital over tumor
Brain exposure	Bilateral cerebellar hemisphere and vermis	Bilateral cerebellar hemisphere eccentric to the right	Bilateral cerebellar hemisphere and vermis	Right cerebellar hemisphere
Method of resection	Midline incision, dissect in avascular plane, midline suboccipital craniotomy, Y-shaped dural opening, identify vermis, transvermian resection over shortest distance to lesion, watertight dural closure, subcutaneous drain	Muscle incision and detachment in one layer, bilateral occipital craniotomy eccentric to right without C1 laminectomy up to inferior edge of transverse sinus, craniotomy without burr hole, V-shaped dural opening, occipital sinus section at bottom, ultrasound-guided resection of lesion through parenchyma, en bloc resection, removal of 5-mm margin with ultrasonic aspirator, watertight dural closure	Craniotomy or craniectomy, bone opening close to torcula and transverse sinus, T-shaped dural opening, drainage of CSF for cisterna magna, work along top of vermis to identify entry point, 1.0-cm vertical incision in the vermis to locate tumor, infernally debulk tumor, infold and remove capsule, inspect cavity to confirm gross total resection, watertight dural closure	Craniotomy encompassing lesion, cruciate dural opening, transcerebellar approach through shortest distance, identification of capsule, internal decompression, mobilization of capsule from surrounding parenchyma, gross total resection, dural closure with synthetic graft
Complication avoidance	Shortest working distance, strict hemostasis	Ultrasound-guided resection, en bloc resection, removal of margin	Bony opening up to transverse sinus/torcula, small corticectomy in vermis, internally debulk tumor prior to mobilizing capsule	Shortest working distance, internal debulking, dural graft
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Hydrocephalus, CSF leak, akinetic mutism	Hydrocephalus, venous engorgement, CSF leak, posterior fossa syndrome	Cerebellar edema, wound healing issues, cerebellar mutism	Cerebellar edema, hydrocephalus
Follow-up testing	MRI within 48 hours after surgery Molecular testing of tumor	CT within 24 hours after surgery MRI within 48 hours after surgeryRadiation oncology evaluation	Possible second stage surgery for perirolandic lesion MRI within 48 hours after surgery	MRI within 48 hours after surgery
Follow-up visits	14 days after surgery, 1 and 3 months after surgery and every 3 months after	4 weeks after surgery prior to radiation therapy	6 weeks after surgery with neurosurgery 2 weeks after surgery with radiation and neurooncology	2 weeks after surgery with radiation and neurooncology
Adjuvant therapies recommended	Postop SRS to cerebellar lesion cavity and other lesion, chemotherapy based on tumor markers	Postop SRS to cerebellar lesion cavity and other lesion	Radiation oncology evaluation for SRS vs. WBRT	Systemic therapy per oncology