A Randomized Trial on the Efficacy of Topical Anesthesia for Pain Reduction during Frame Placement for Gamma Knife Radiosurgery.
Frame application for gamma knife radiosurgery (GKR) may be perceived as painful by patients. This study was designed to assess the efficacy of EMLA (2.5% lidocaine/2.5% prilocaine) in pain reduction.



This was a prospective, randomized, and controlled trial approved by our institutional review board. Fifty-four patients undergoing outpatient GKR were divided into EMLA and placebo groups. Prior to frame placement, EMLA/placebo was applied to the patient's forehead. A visual analog scale (VAS) was used to measure pain during 4 intervals: frontal injections, occipital injections, frontal screw insertion, and overall discomfort. This study was designed to observe a difference of 1.0 on the VAS at a power of 95%.



VAS for EMLA versus placebo for frontal injections (5.2 ± 2.7 vs. 5.7 ± 2.0, respectively; p < 0.45), back injections, (6.5 ± 2.2 vs. 5.9 ± 2.3, respectively; p < 0.30), frontal pins (4.6 ± 2.7 vs. 4.6 ± 2.2, respectively; p < 0.99), and overall discomfort (p < 0.29) were not significantly different. A comparison between back and frontal injections for EMLA (6.54 vs. 5.19, respectively; p < 0.16) and placebo (5.89 vs. 5.68, respectively; p < 0.69) showed no significant difference between group and location (p < 0.21).



Application of EMLA did not significantly reduce pain when used preoperatively for frame fixation. EMLA is no longer used as part of our routine for patients undergoing GKR.
Northwell Health System, Brain Tumor Center, Lake Success, N.Y., USA.
Sean Michael
SM
Duenas
Jonathan
J
Pun
Hesham A
HA
Radwan
Meredith
M
Akerman
Michael
M
Schulder
D000287:Administration, Topical; D000328:Adult; D000368:Aged; D000779:Anesthetics, Local / Q000008:administration & dosage*; D001927:Brain Diseases / Q000601:surgery*; D005546:Forehead; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage*; D000077442:Lidocaine, Prilocaine Drug Combination; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy* / Q000209:etiology; D011318:Prilocaine / Q000008:administration & dosage*; D011446:Prospective Studies; D016634:Radiosurgery / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods*; D016896:Treatment Outcome
D000779:Anesthetics, Local; D000077442:Lidocaine, Prilocaine Drug Combination; D011318:Prilocaine; D008012:Lidocaine