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Predictive Variables for Successful Treatment of Trigeminal Neuralgia with Radiosurgery
I. J. Radiation Oncology d Biology d Physics
S8 1
Volume 78, Number 3, Supplement, 2010
Joe Arrington Cancer Center, Lubbock, TX, 2Texas Tech University, Lubbock, TX, 3Good Samaritan Hospital, Los Angeles, CA
Purpose/Objective(s): Gamma Knife Radiosurgery (GKRS) has been used successfully in the treatment of Trigeminal Neuralgia (TN). Results have compared favorably to surgical procedures with respect to pain relief and complications. We report our updated long-term results with GKRS in the treatment of TN. Materials/Methods: Between 1991 and 2010, 538 patients with medically refractory typical TN were treated with GKRS, and have not been lost to follow-up. Prior neurosurgical intervention had been performed in 30.1% of the patients (162/538), with a total of 369 procedures. All patients had typical TN. GKRS was given to the cranial nerve V entry root zone into the brainstem. Targeting was defined by CT and MRI Scans, and inversion recovery MRI, utilizing axial, coronal and sagittal images. Treatment planning was accomplished thru a computerized 3-Dimensional Treatment Planning System. The prescribed doses ranged from 70 to 90 Gy prescribed to Dm, in one shot using the 4 mm collimator, with the 20% Isodose line just touching the brainstem. Response to treatment was defined as excellent (no pain, off analgesics), good (no pain, with analgesics), and poor (continued pain despite analgesics). Response to treatment was recorded in interviews conducted by a Gamma Knife Nurse. Results: With a median follow-up of 10 years (range, 5-19 years), 54.1% (291/538) of patients reported an excellent result, and 22.8% (123/538) a good result after GKRS. There was a dose response, with 55.7% (68/122) of patients reporting an excellent or good response after 70 Gy, compared to 81.1% (202/249) at 80 Gy, and 86.2% (144/167) at 90 Gy (p\ 0.01). Temporary ipsilateral facial numbness occurred in 18.6% (100/538), and permanent facial numbness in 5.0% (27/538). Loss of corneal reflex occurred in 1.5% (8/538), and painful dysesthesias in 2.8% (15/538). There have been three cases of anesthesia dolorosa. There was a dose response in facial numbness, with temporary numbness occurring in 6.5% (8/122) at 70 Gy, 17.3% (43/249) at 80 Gy, and 29.3% (49/167) at 90 Gy (p\0.01). Permanent numbness occurred in 2.5% (3/122) at 70 Gy, 3.6% (9/249) at 80 Gy, and 9.0% (15/167) at 90 Gy (p \ 0.01). Conclusions: GKRS offers favorable results, both in pain relief and complications, compared to surgery in the management of medically refractory TN. In view of these long-term good pain relief and low complication risks, GKRS should be considered as a primary initial treatment option in medically refractory TN. The optimal dose with maximum pain relief and minimal complications, appears to be 80 Gy. Author Disclosure: T. Martin, None; R.J. Mark, None; H. Smith, None; D. Jacques, None; R. Young, None; B. Copcutt, None; C. Chen, None; M. Nair, None; P. Anderson, None.
17
Predictive Variables for Successful Treatment of Trigeminal Neuralgia with Radiosurgery
K. M. Marshall1, M. D. Chan1, T. L. Ellis1, A. Aubuchon1, C. J. Balamucki2, J. D. Bourland1, T. P. McCoy1, K. P. McMullen1, E. G. Shaw1, S. B. Tatter1 1
Wake Forest University School of Medicine, Winston-Salem, NC, 2University of Florida, Gainesville, FL
Purpose/Objective(s): Gamma Knife Radiosurgery (GKRS) has been reported as a definitive management approach for medically refractory trigeminal neuralgia (TN). Controversy persists regarding factors that predict for treatment success and toxicity. Materials/Methods: Between September 1999 and December 2008, 777 GKRS procedures for patients with TN were performed at our institution. Follow-up was obtained via patient electronic medical records and telephone interview. Patients reported pain control following GKRS as excellent (100% pain relief no medication), good (100% pain relief with medication), fair (50-99% pain relief) or poor (\50% pain relief). Leksell GammaPlan software was used to measure cisternal nerve length (mm) and maximum dose (Gy) delivered to dorsal root entry zone (DREZ), pons, and the point of trigeminal nerve contact with the petrous dura. Targeting philosophy changed during the course of the series; DREZ was included in the target early in the series while more distal targets were favored later. Median dose for the series was 90 Gy with a single 4mm collimator and collimator output factor of 0.87. Results: Follow-up data were obtainable for 504 patients with initial GKRS procedures for TN. Median follow-up time was 11.8 months. Overall, 83.3% of patients experienced an improvement in quality of life. 26% of patients developed some degree of facial numbness. 26% of patients reported a post-GKRS procedure with median time to next procedure (repeat GKRS, microvascular decompression or other procedure) of 4.4 years among those patients. Post-surgical numbness was a highly predictive variable for .50% pain relief (OR 3.2, p = 0.001). Multivariate analysis revealed that longer cisternal nerve length (OR 0.84, p = 0.002), diabetic status (OR 0.35, p = 0.006),and prior radiofrequency ablation (OR 0.34, p = 0.021) predicted for decreased likelihood of .50% pain relief. Higher DREZ dose predicted for development of facial numbness (mean 55.97 Gy vs. 47.12 Gy, p = 0.001); however, facial numbness was found to be the more significant predictor of treatment success on logistic regression (OR 3.2, p = 0.001). None of DREZ dose, distal nerve dose, or pontine max dose predicted for .50% pain relief. Conclusions: This review is the largest reported GKRS case series for the treatment of TN. The data suggest that the TN targeting location selected for the prescribed dose does not predict for treatment outcome. Author Disclosure: K.M. Marshall, None; M.D. Chan, None; T.L. Ellis, None; A. Aubuchon, None; C.J. Balamucki, None; J.D. Bourland, None; T.P. McCoy, None; K.P. McMullen, None; E.G. Shaw, None; S.B. Tatter, None.
18
Conventionally Fractionated Stereotactic Radiotherapy for Vestibular Schwannoma: A Single Institutional Long-term Outcomes
H. Aoyama1,2, N. Takeichi3, S. Onodera4, H. Taguchi5, Y. Sawamura6, H. Shirato5 1 Department of Radiology, Niigata University School of Med., Niigata, Japan, 2Department of Radiology, Hokkaido University School of Med., Sapporo, Japan, 3Department of Otolaryngology, Hokkaido University Graduate School of Medicine, Sapporo, Japan, 4 Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan, 5Department of Radiology, Hokkaido University School of Med., Sapporo, Japan, 6Department of Neurosurgery, Hokkaido University School of Med., Sapporo, Japan
Purpose/Objective(s): To confirm the importance of long-term follow-up after stereotactic radiotherapy (SRT) for vestibular schwannoma including those larger than 3cm. Materials/Methods: The long-term outcome of 201 patients who received SRT for vestibular schwannoma in Hokkaido University Hospital was retrospectively reviewed. The maximum diameter of tumors was \ 10mm in 13 patients (6%), 10-19mm in 79 patients (39%), 20-29mm in 87 patients (43%), and . = 30mm in 22 patients (11%). Pre-treatment communicating hydrocephalus was observed in 15 patients (7%). Pre-treatment useful hearing was preserved (Gardner-Robertson class I or II) in 75 patients
S8 1
Volume 78, Number 3, Supplement, 2010
Joe Arrington Cancer Center, Lubbock, TX, 2Texas Tech University, Lubbock, TX, 3Good Samaritan Hospital, Los Angeles, CA
Purpose/Objective(s): Gamma Knife Radiosurgery (GKRS) has been used successfully in the treatment of Trigeminal Neuralgia (TN). Results have compared favorably to surgical procedures with respect to pain relief and complications. We report our updated long-term results with GKRS in the treatment of TN. Materials/Methods: Between 1991 and 2010, 538 patients with medically refractory typical TN were treated with GKRS, and have not been lost to follow-up. Prior neurosurgical intervention had been performed in 30.1% of the patients (162/538), with a total of 369 procedures. All patients had typical TN. GKRS was given to the cranial nerve V entry root zone into the brainstem. Targeting was defined by CT and MRI Scans, and inversion recovery MRI, utilizing axial, coronal and sagittal images. Treatment planning was accomplished thru a computerized 3-Dimensional Treatment Planning System. The prescribed doses ranged from 70 to 90 Gy prescribed to Dm, in one shot using the 4 mm collimator, with the 20% Isodose line just touching the brainstem. Response to treatment was defined as excellent (no pain, off analgesics), good (no pain, with analgesics), and poor (continued pain despite analgesics). Response to treatment was recorded in interviews conducted by a Gamma Knife Nurse. Results: With a median follow-up of 10 years (range, 5-19 years), 54.1% (291/538) of patients reported an excellent result, and 22.8% (123/538) a good result after GKRS. There was a dose response, with 55.7% (68/122) of patients reporting an excellent or good response after 70 Gy, compared to 81.1% (202/249) at 80 Gy, and 86.2% (144/167) at 90 Gy (p\ 0.01). Temporary ipsilateral facial numbness occurred in 18.6% (100/538), and permanent facial numbness in 5.0% (27/538). Loss of corneal reflex occurred in 1.5% (8/538), and painful dysesthesias in 2.8% (15/538). There have been three cases of anesthesia dolorosa. There was a dose response in facial numbness, with temporary numbness occurring in 6.5% (8/122) at 70 Gy, 17.3% (43/249) at 80 Gy, and 29.3% (49/167) at 90 Gy (p\0.01). Permanent numbness occurred in 2.5% (3/122) at 70 Gy, 3.6% (9/249) at 80 Gy, and 9.0% (15/167) at 90 Gy (p \ 0.01). Conclusions: GKRS offers favorable results, both in pain relief and complications, compared to surgery in the management of medically refractory TN. In view of these long-term good pain relief and low complication risks, GKRS should be considered as a primary initial treatment option in medically refractory TN. The optimal dose with maximum pain relief and minimal complications, appears to be 80 Gy. Author Disclosure: T. Martin, None; R.J. Mark, None; H. Smith, None; D. Jacques, None; R. Young, None; B. Copcutt, None; C. Chen, None; M. Nair, None; P. Anderson, None.
17
Predictive Variables for Successful Treatment of Trigeminal Neuralgia with Radiosurgery
K. M. Marshall1, M. D. Chan1, T. L. Ellis1, A. Aubuchon1, C. J. Balamucki2, J. D. Bourland1, T. P. McCoy1, K. P. McMullen1, E. G. Shaw1, S. B. Tatter1 1
Wake Forest University School of Medicine, Winston-Salem, NC, 2University of Florida, Gainesville, FL
Purpose/Objective(s): Gamma Knife Radiosurgery (GKRS) has been reported as a definitive management approach for medically refractory trigeminal neuralgia (TN). Controversy persists regarding factors that predict for treatment success and toxicity. Materials/Methods: Between September 1999 and December 2008, 777 GKRS procedures for patients with TN were performed at our institution. Follow-up was obtained via patient electronic medical records and telephone interview. Patients reported pain control following GKRS as excellent (100% pain relief no medication), good (100% pain relief with medication), fair (50-99% pain relief) or poor (\50% pain relief). Leksell GammaPlan software was used to measure cisternal nerve length (mm) and maximum dose (Gy) delivered to dorsal root entry zone (DREZ), pons, and the point of trigeminal nerve contact with the petrous dura. Targeting philosophy changed during the course of the series; DREZ was included in the target early in the series while more distal targets were favored later. Median dose for the series was 90 Gy with a single 4mm collimator and collimator output factor of 0.87. Results: Follow-up data were obtainable for 504 patients with initial GKRS procedures for TN. Median follow-up time was 11.8 months. Overall, 83.3% of patients experienced an improvement in quality of life. 26% of patients developed some degree of facial numbness. 26% of patients reported a post-GKRS procedure with median time to next procedure (repeat GKRS, microvascular decompression or other procedure) of 4.4 years among those patients. Post-surgical numbness was a highly predictive variable for .50% pain relief (OR 3.2, p = 0.001). Multivariate analysis revealed that longer cisternal nerve length (OR 0.84, p = 0.002), diabetic status (OR 0.35, p = 0.006),and prior radiofrequency ablation (OR 0.34, p = 0.021) predicted for decreased likelihood of .50% pain relief. Higher DREZ dose predicted for development of facial numbness (mean 55.97 Gy vs. 47.12 Gy, p = 0.001); however, facial numbness was found to be the more significant predictor of treatment success on logistic regression (OR 3.2, p = 0.001). None of DREZ dose, distal nerve dose, or pontine max dose predicted for .50% pain relief. Conclusions: This review is the largest reported GKRS case series for the treatment of TN. The data suggest that the TN targeting location selected for the prescribed dose does not predict for treatment outcome. Author Disclosure: K.M. Marshall, None; M.D. Chan, None; T.L. Ellis, None; A. Aubuchon, None; C.J. Balamucki, None; J.D. Bourland, None; T.P. McCoy, None; K.P. McMullen, None; E.G. Shaw, None; S.B. Tatter, None.
18
Conventionally Fractionated Stereotactic Radiotherapy for Vestibular Schwannoma: A Single Institutional Long-term Outcomes
H. Aoyama1,2, N. Takeichi3, S. Onodera4, H. Taguchi5, Y. Sawamura6, H. Shirato5 1 Department of Radiology, Niigata University School of Med., Niigata, Japan, 2Department of Radiology, Hokkaido University School of Med., Sapporo, Japan, 3Department of Otolaryngology, Hokkaido University Graduate School of Medicine, Sapporo, Japan, 4 Department of Radiology, Hokkaido University Graduate School of Medicine, Sapporo, Japan, 5Department of Radiology, Hokkaido University School of Med., Sapporo, Japan, 6Department of Neurosurgery, Hokkaido University School of Med., Sapporo, Japan
Purpose/Objective(s): To confirm the importance of long-term follow-up after stereotactic radiotherapy (SRT) for vestibular schwannoma including those larger than 3cm. Materials/Methods: The long-term outcome of 201 patients who received SRT for vestibular schwannoma in Hokkaido University Hospital was retrospectively reviewed. The maximum diameter of tumors was \ 10mm in 13 patients (6%), 10-19mm in 79 patients (39%), 20-29mm in 87 patients (43%), and . = 30mm in 22 patients (11%). Pre-treatment communicating hydrocephalus was observed in 15 patients (7%). Pre-treatment useful hearing was preserved (Gardner-Robertson class I or II) in 75 patients