TY - JOUR
T1 - Radiosurgical target distance from the root entry zone in the treatment of trigeminal neuralgia
AU - Sharim, Justin
AU - Lo, Wei Lun
AU - Kim, Won
AU - Chivukula, Srinivas
AU - Tenn, Stephen
AU - Kaprealian, Tania
AU - Pouratian, Nader
N1 - Publisher Copyright:
© 2016 American Society for Radiation Oncology
PY - 2017/7
Y1 - 2017/7
N2 - Purpose Stereotactic radiosurgery (SRS) provides a noninvasive treatment modality for patients with medically refractory trigeminal neuralgia. The root entry zone (REZ) has been proposed to be an ideal stereotactic target because it is partially composed of centrally produced myelin, conferring a theoretical increased sensitivity to irradiation as well as increased susceptibility to neurovascular conflict, making it the site in which nociceptive signals likely arise. The aim of this study is to determine if there is a statistically and clinically significant difference in pain relief or facial hypesthesia following SRS based on distance of the stereotactic isocenter from REZ. Methods and materials Patients undergoing Novalis radiosurgery for the treatment of trigeminal neuralgia with at least 3 months’ follow-up were included in this study. Postoperative outcomes were stratified by Barrow Neurological Institute (BNI) score for pain relief and BNI facial numbness score for facial hypesthesia. Results Sixty-seven patients met inclusion criteria and were included in this study. BNI score of I-IIIa was attained in 82% of patients at 3 months and 65% at 1 year following SRS. Distance from isocenter to REZ varied from 0 to 8.6 mm, with a mean of 1.94 ± 1.62 mm. Logistic regression of target-REZ distance against pain relief outcome (patients with score I-IIIa and IIIb-V) was insignificant at 3 months (P =.988), 6 months (P =.925), 9 months (P =.845), and 12 months (P =.547) postoperatively. Furthermore, no significant correlation was found with logistic regression of target-REZ distance with pain relief outcome (patients with score I and score II-IV) (P =.544). Conclusions The current analysis suggests that distance from REZ does not correlate with degree of postoperative pain relief or facial hypesthesia; thus, targeting specific regions within the trigeminal nerve in relation to these anatomical characteristics may not afford any advantage from this perspective.
AB - Purpose Stereotactic radiosurgery (SRS) provides a noninvasive treatment modality for patients with medically refractory trigeminal neuralgia. The root entry zone (REZ) has been proposed to be an ideal stereotactic target because it is partially composed of centrally produced myelin, conferring a theoretical increased sensitivity to irradiation as well as increased susceptibility to neurovascular conflict, making it the site in which nociceptive signals likely arise. The aim of this study is to determine if there is a statistically and clinically significant difference in pain relief or facial hypesthesia following SRS based on distance of the stereotactic isocenter from REZ. Methods and materials Patients undergoing Novalis radiosurgery for the treatment of trigeminal neuralgia with at least 3 months’ follow-up were included in this study. Postoperative outcomes were stratified by Barrow Neurological Institute (BNI) score for pain relief and BNI facial numbness score for facial hypesthesia. Results Sixty-seven patients met inclusion criteria and were included in this study. BNI score of I-IIIa was attained in 82% of patients at 3 months and 65% at 1 year following SRS. Distance from isocenter to REZ varied from 0 to 8.6 mm, with a mean of 1.94 ± 1.62 mm. Logistic regression of target-REZ distance against pain relief outcome (patients with score I-IIIa and IIIb-V) was insignificant at 3 months (P =.988), 6 months (P =.925), 9 months (P =.845), and 12 months (P =.547) postoperatively. Furthermore, no significant correlation was found with logistic regression of target-REZ distance with pain relief outcome (patients with score I and score II-IV) (P =.544). Conclusions The current analysis suggests that distance from REZ does not correlate with degree of postoperative pain relief or facial hypesthesia; thus, targeting specific regions within the trigeminal nerve in relation to these anatomical characteristics may not afford any advantage from this perspective.
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U2 - 10.1016/j.prro.2016.12.006
DO - 10.1016/j.prro.2016.12.006
M3 - Article
C2 - 28336479
AN - SCOPUS:85015779210
SN - 1879-8500
VL - 7
SP - 221
EP - 227
JO - Practical Radiation Oncology
JF - Practical Radiation Oncology
IS - 4
ER -