Trigeminal Neuralgia Treated With Stereotactic Radiosurgery: The Effect of Dose Escalation on Pain Control and Treatment Outcomes.
To analyze the effect of dose escalation on treatment outcome in patients undergoing stereotactic radiosurgery (SRS) for trigeminal neuralgia (TN).



A retrospective review was performed of 870 patients who underwent SRS for a diagnosis of TN from 2 institutions. Patients were typically treated using a single 4-mm isocenter placed at the trigeminal nerve dorsal root entry zone. Patients were divided into groups based on treatment doses: ≤82 Gy (352 patients), 83 to 86 Gy (85 patients), and ≥90 Gy (433 patients). Pain response was classified using a categorical scoring system, with fair or poor pain control representing treatment failure. Treatment-related facial numbness was classified using the Barrow Neurological Institute scale. Log-rank tests were performed to test differences in time to pain failure or development of facial numbness for patients treated with different doses.



Median age at first pain onset was 63 years, median age at time of SRS was 71 years, and median follow-up was 36.5 months from the time of SRS. A majority of patients (827, 95%) were clinically diagnosed with typical TN. The 4-year rate of excellent to good pain relief was 87% (95% confidence interval 84%-90%). The 4-year rate of pain response was 79%, 82%, and 92% in patients treated to ≤82 Gy, 83 to 86 Gy, and ≥90 Gy, respectively. Patients treated to doses ≤82 Gy had an increased risk of pain failure after SRS, compared with patients treated to ≥90 Gy (hazard ratio 2.0, P=.0007). Rates of treatment-related facial numbness were similar among patients treated to doses ≥83 Gy. Nine patients (1%) were diagnosed with anesthesia dolorosa.



Dose escalation for TN to doses >82 Gy is associated with an improvement in response to treatment and duration of pain relief. Patients treated at these doses, however, should be counseled about the increased risk of treatment-related facial numbness.
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio.
Rupesh
R
Kotecha
MidMichigan Medical Center, Midland, Michigan.
Ritesh
R
Kotecha
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio.
Sujith
S
Modugula
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio; Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio.
Erin S
ES
Murphy
MidMichigan Medical Center, Midland, Michigan.
Mark
M
Jones
MidMichigan Medical Center, Midland, Michigan.
Rajesh
R
Kotecha
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio.
Chandana A
CA
Reddy
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio; Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio.
John H
JH
Suh
Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio; Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
Gene H
GH
Barnett
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio; Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio.
Gennady
G
Neyman
Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
Andre
A
Machado
Department of Neurosurgery, Neurological Institute, Cleveland Clinic, Cleveland, Ohio.
Sean
S
Nagel
Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio; Rose Ella Burkhardt Brain Tumor and Neuro-Oncology Center, Cleveland Clinic, Cleveland, Ohio. Electronic address: chaos@ccf.org.
Samuel T
ST
Chao
D000293:Adolescent; D000328:Adult; D000368:Aged; D015984:Causality; D002648:Child; D015897:Comorbidity; D004305:Dose-Response Relationship, Drug; D005157:Facial Pain / Q000175:diagnosis / Q000453:epidemiology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008824:Michigan / Q000453:epidemiology; D008875:Middle Aged; D009820:Ohio / Q000453:epidemiology; D010147:Pain Measurement / Q000528:radiation effects / Q000706:statistics & numerical data*; D015995:Prevalence; D000069473:Radiation Dose Hypofractionation; D016634:Radiosurgery / Q000379:methods / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D014277:Trigeminal Neuralgia / Q000175:diagnosis / Q000453:epidemiology* / Q000532:radiotherapy*; D055815:Young Adult