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metastases may produce debilitating neurologi-
cal symptoms that warrant surgical intervention
despite no increase in patient survival and a
greater chance of postoperative morbidity [ 36 ].
These cases should be approached judiciously;
however, the opportunity to offer recourse from
debilitating neurological impairment for a patient
who has months to live cannot be overstated. A
neurosurgeon must weigh all aspects of a patient’s
condition, as well as his or her own technical
abilities, and exercise the appropriate clinical
judgment.
For treatment of brain metastases, management
algorithms seek to provide evidence-based prog-
nostic indicators to inform treatment decisions.
The recursive partitioning analysis (RPA) classifi-
cation scale devised by Gaspar and associates
within the Radiation Therapy Oncology Group is a
well-known prognostication tool [ 37 ]. Notably,
the RPA for brain metastasis is divided into three
prognostic categories, incorporating Karnofsky
performance scale (KPS) metrics as well as age
and systemic disease state (Table 13.1). Class I
patients appear to benefit the most from any thera-
peutic modalities, such as surgery, SRS, or WBRT,
and tend to have KPS ≥70, controlled extracranial
disease, and an age of <65 years. Most patients fall
into Class II, with ambiguous benefit depending
on the patient, disease, and therapeutic options
available. Class III patients (KPS <70) do not con-
sistently benefit from therapy, no matter the
modality, and have a median survival of approxi-
mately 2 months [ 37 ]. Therefore, the decision to
operate must be considered within the context of
the systemic disease, and more advanced systemic
disease often predicts short-term survival regard-
less of intracranial tumor burden [ 38 , 39 ].
Because of the short overall median survival
times often seen in patients with brain metastasis
(8–12 months), much of a neurosurgeon’s efforts
may be palliative and short; however, with appro-
priate patient selection, instances of long-term sur-
vivors will continue to increase. For patients with
high tumor burdens and multiple metastases, SRSFig. 13.3 Images of a patient with newly diagnosed lung
cancer and solitary posterior fossa metastatic lesion. (a, b)
Preoperative MRIs demonstrate (a) large enhancing mass
on axial T1-weighted gadolinium-enhanced image; (b)
coronal section of the same sequence both demonstrate
significant mass effect and fourth ventricular compres-
sion. (c, d) Preoperative (c) T2-weighted and (d) FLAIR
images demonstrate peritumoral edema. (e–h) Immediate
postoperative (e) axial T1-weighted, gadolinium-
enhanced, (f) coronal and (g) axial T2-weighted, and (h)
FLAIR images demonstrate resection of the lesion, reso-
lution of mass effect, and improving peritumoral edemaB.D. Weaver and R.L. Jensen