Gamma Knife, LINAC, and Proton Beam:
comparison of recent radiosurgery outcomes

contributed by Dick Barker

Additional useful information in the Acoustic Neuroma Patient Archive:

Outcome Measure

Pittsburgh GK Virginia GK Jefferson Univ GK Jefferson Univ FSR Johns Hopkins FSR Stanford FSR Staten Island Univ. Hosp. FSR Loma Linda Proton
Tumor Growth Control Rate 97.1
+/- 1.9%
94% 98% 97-
100%
100% 97% 99% 100%
New-onset of transient or permanent facial weakness

1.1
+/- 0.8%1

2.2% trans / 0-1.3% perm 2% 7% 0% 3% 0-1% 0%
New-onset of transient or permanent facial numbness 2.6
+/- 1.2%
4% trans /
1.6% perm
2% 2% 0% 16% 0-1% 0%
Hearing-level preservation 71+/-4.7% 58%     73% 77% 69-94  
Preservation of useful hearing2 73.5+/-5.9%   33%
(4 of 12)
81% (17 of 21)       31%
(4 of 13)
Improved or resolved tinnitus   11%
(3 of 26)
           

Treatment Details

Pittsburgh GK Virginia GK Jefferson Univ GK Jefferson Univ FSR Johns Hopkins FSR Stanford FSR Staten Island Univ. Hosp. FSR Loma Linda Proton
Number of patients included     69 65 125     30
Period of follow-up (years) 2-7 1-10 2.3 2.2 1-5.7 0.5-4 3.5 yrs 2.8
Tumor size (cm):
mean diameter / range
1.72 /
0.6-4
1.74 /
0.3-3.2
1.77 1.74 1.2 - 9.3cc3 2.0 /
0.7-4.2
2.6 cm 2.0 cm
Tumor dosage (Gy):
mean / range
26 /
22-36
34.3 /
17-53
? 50 Gy
in 35 fractions
25-30 in
5 or 10
fractions
21 Gy
in 3
fractions
20 Gy
in 4 or 5
fractions
54 Gy
in 30 fractions
Dosage to tumor margin (Gy):
mean / range
13 /
11-18
13.2 12 Gy          
  1. Facial weakness did not develop in any patient who received a marginal dose of less than 15 Gy (163 patients).
  2. Useful hearing in the affected ear means "testable speech discrimination", defined as Gardner-Robertson grades 1 and 2, PTA (pure tone average) at 0-50dB and SDS (speech discrimination score) at 50-100%; hearing levels below that are not considered useful, and were not reported.
  3. The tumor was measured by volume (cc's) rather than size (cm's).

Sources:

Last Edited: Saturday, February 14, 2004