The Role of Radiosurgery

The American Association of Neurological Surgeons & the Congress of Neurological Surgeons

Should patients with newly-diagnosed metastatic brain tumors undergo stereotactic radiosurgery (SRS) compared with other treatment modalities?

Target population

These recommendations apply to adults with newly diagnosed solid brain metastases
amenable to SRS; lesions amenable to SRS are typically defined as measuring less
than 3 cm in maximum diameter and producing minimal (less than 1 cm of midline shift)
mass effect.
 

Recommendations

SRS plus WBRT vs. WBRT alone

Level 1 Single-dose SRS along with WBRT leads to significantly longer patient survival
compared with WBRT alone for patients with single metastatic brain tumors who have a
KPS ≥ 70.
 
Level 2 Single-dose SRS along with WBRT is superior in terms of local tumor control
and maintaining functional status when compared to WBRT alone for patients with 1–4
metastatic brain tumors who have a KPS ≥ 70.
 
Level 3 Single-dose SRS along with WBRT may lead to significantly longer patient
survival than WBRT alone for patients with 2–3 metastatic brain tumors.
 
Level 4 There is class III evidence demonstrating that single-dose SRS along with
WBRT is superior to WBRT alone for improving patient survival for patients with single
or multiple brain metastases and a KPS < 70.
 

SRS plus WBRT vs. SRS alone

Level 2 Single-dose SRS alone may provide an equivalent survival advantage for
patients with brain metastases compared with WBRT + single-dose SRS. There is
conflicting class I and II evidence regarding the risk of both local and distant recurrence
when SRS is used in isolation, and class I evidence demonstrates a lower risk of distant
recurrence with WBRT; thus, regular careful surveillance is warranted for patients
treated with SRS alone in order to provide early identification of local and distant
recurrences so that salvage therapy can be initiated at the soonest possible time.
 

Surgical Resection plus WBRT vs. SRS ± WBRT

Level 2 Surgical resection plus WBRT, vs. SRS plus WBRT, both represent effective
treatment strategies, resulting in relatively equal survival rates. SRS has not been
assessed from an evidence-based standpoint for larger lesions (>3 cm) or for those
causing significant mass effect (>1 cm midline shift). Level 3: Underpowered class I
evidence along with the preponderance of conflicting class II evidence suggests that
SRS alone may provide equivalent functional and survival outcomes compared with
resection + WBRT for patients with single brain metastases, so long as ready detection
of distant site failure and salvage SRS are possible.
 

SRS alone vs. WBRT alone

Level 3 While both single-dose SRS and WBRT are effective for treating patients with
brain metastases, single-dose SRS alone appears to be superior to WBRT alone for
patients with up to three metastatic brain tumors in terms of patient survival advantage.