Gamma K nife Radiosurgery (G KS) Marianne Flatebø Sidsel Bragstad Kjersti Klett Haukeland University Hospital Bergen, Norway

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1 Gamma K nife Radiosurgery (G KS) Marianne Flatebø Sidsel Bragstad Kjersti Klett Haukeland University Hospital Bergen, Norway

2 40 years of research and development

3 Other types of radiation therapy Linac or Cyber - knife

4 Gamma knife Converging rays/ heterogeneous dose fields

5 Designed to treat deeply seated lesions 192 gamma rays intersect at a focal point Provides high dose to small volumes

6 The stereotactic frame and indicator box

7

8 The three collimators can be combined to provide larger or smaller fields with high radiation. Thereby we can "fill" the tumor with high radiation either by combining different radiation field sizes or by placing a small amount of radiation at the tumor periphery.

9 The aim of radiation is to damage the genetic material and thereby prevent further tumor growth. Radiobiology

10 T reatment Procedure

11 Vaskul ære 10% Other 3% Maligne 47% Benigne 40% Other functional Vascular Malignant Benign

12 Pain during the Gamma K nife Procedure a Randomized Prospective Study of Bupivacaine vs. Lidocaine at pin sites Marianne Flatebø, Sidsel Bragstad, Elisabeth Larsen, Kjersti Klett, Eirik Johansen, Håvard Teksle and Bente Skeie, Haukeland University Hospital, Bergen, Norway

13 Introduction Gamma Knife Surgery (GKS) is increasingly used for benign and malignant tumors, arteriovenous malformations (AVM) and functional disorders of the brain The procedure is usually performed in local anesthesia. Patients often experience different degrees of pain not only during frame application itself, but also during GKS and even within the first hour post frame removal

14 Aim Our aim was to prospectively investigate the influence on pain during GKS of a longer acting anesthetics mixed with a shorter acting (sc. Bupivacaine/ Lidocaine) at pin sites vs. a shorter acting anesthetics (sc. Lidocaine) alone

15 Material and Methods 104 consecutive patients treated with GKS at Haukeland University hospital, Bergen, between February 2013 until June 2013 were randomized to either: 1) A mixture of 50 % Bupivacaine 5 mg/ml and 50 % Lidocaine 10 mg/ml sc. (53 patients) at pin sites or 2) Lidocaine 10 mg/ml sc. (51 patients) Mean 16 ml (range 7-25 ml ) of local anesthesia was applied mean 2 min (range 0-7 min) before frame application

16 Material and Methods Pain was assessed by the patients on the Visual Analogue Scale for pain (VAS) Patients were asked to assess VAS after: - frame application - the first 5 minutes after frame application - imaging and GKS - the first hour post frame removal

17 Comparable treatment groups: Lidocain (L) Bupivacain + L p-value No patients ns Age 58.4 (31-86) 59.8 (23-80) ns F:M 27:26 33:18 ns Brain metastases: meningioma: acoustic neuroma: other 26 : 8: 12:7 18: 15: 9: 9 ns Prior G KS 10 (18.9 %) 13 (25.5 %) ns Pre-medication (oxazepam 10 mg) 34 (65.4 %) 32 (62.7 %) ns Anesthetic Dose 13.3 ml 16.4 ml ns Time from sc. local to frame application 2.0 min 2.1 min ns

18 Results: VAS-score all 104 patients Frame application: mean 2.9 (median 3, range 0-10 ) First 5 min after application: mean 2.6 (median 2, range 0-9) During imaging/ GKS: mean 0.7 (median 0, range 0-8 ) First hour after GKS: mean 2.0 (median 1, range 0-8 )

19 Main Results Pain intensity at frame application itself was equal in the two groups (p = 0.726) Pain intensity during most of the treatment day (mean 5.0 h) was less in the Bupivacaine group (mean VAS 0.24 vs. 0.68, p = 0.002) Pain intensity the first 5 min after frame application was less in the Lidocaine alone group (mean VAS 2.30 vs. 2.96, p = 0.043)

20 Treatment time Treatment time: < 3 hours (h): 16 patients > 3 h: 88 patients Treatment time < 3 h was associated with less pain - during imaging (mean VAS 0.08 vs. 0.8, p= 0.003) - GKS (mean VAS 0 vs. 0.5, p= 0.004) - 1 hour after frame removal (mean VAS 1.0 vs. 2.1, p= 0.036)

21 Other factors The dose of local anesthetic and the time from the local anesthetic was given to frame application did not impact on VAS (ns) Patients previously treated with GKS experienced significantly less pain during frame application, p = (VAS: 2.89 vs. 1.70)

22 Additional findings More intense pain was reported by: Females vs. males (mean VAS-score first h after frame removal: 2.45 vs. 1.24, p = 0.004) Younger patients vs. older ( p < 0.001) at all time points after frame application both as continuous vs. > 65 years.

23 More intense pain was reported by: Patients with benign conditions (acoustic neuroma, (AVM, ACU and meningioma) vs. malignant conditions (brain metastases (BM) and malignant glioma); mean VAS-score 0.55 vs. 0.17, p = Patients with A C U vs. meningioma or B M patients that reported the lowest VAS-score at frame application (p= 0.034) and after frame removal (p = 0.012)

24 Conclusion Headache/ pain at pin sites was the same at frame application for both treatment groups, but the Bupivacain group experienced significantly less pain during the rest of the treatment day, except for the first 5 minutes after frame application A mixture of the longer acting Bupivacaine with Lidocaine may therefore be beneficial to reduce pain during the GKS procedure