Abstract：
OBJECTIVE: Recent studies have suggested that biologically effective dose (BED) is an important correlate of pain relief and sensory dysfunction after Gamma Knife radiosurgery (GKRS) for trigeminal neuralgia (TN). The goal of this study was to determine if BED is superior to prescription dose in predicting outcomes in TN patients undergoing GKRS as a first procedure.
METHODS: This was a retrospective study of 871 patients with type 1 TN from 13 GKRS centers. Patient demographics, pain characteristics, treatment parameters, and outcomes were reviewed. BED was compared with prescription dose and other dosimetric factors for their predictive value.
RESULTS: The median age of the patients was 68 years, and 60% were female. Nearly 70% of patients experienced pain in the V2 and/or V3 dermatomes, predominantly on the right side (60%). Most patients had modified BNI Pain Intensity Scale grade IV or V pain (89.2%) and were taking 1 or 2 pain medications (74.1%). The median prescription dose was 80 Gy (range 62.5-95 Gy). The proximal trigeminal nerve was targeted in 77.9% of cases, and the median follow-up was 21 months (range 6-156 months). Initial pain relief (modified BNI Pain Intensity Scale grades I-IIIa) was noted in 81.8% of evaluable patients at a median of 30 days. Of 709 patients who achieved initial pain relief, 42.3% experienced at least one pain recurrence after GKRS at a median of 44 months, with 49.0% of these patients undergoing a second procedure. New-onset facial numbness occurred in 25.3% of patients after a median of 8 months. Age ≥ 63 years was associated with a higher probability of both initial pain relief and maintaining pain relief. A distal target location was associated with a higher probability of initial and long-term pain relief, but also a higher incidence of sensory dysfunction. BED ≥ 2100 Gy2.47 was predictive of pain relief at 30 days and 1 year for the distal target, whereas physical dose ≥ 85 Gy was significant for the proximal target, but the restricted range of BED values in this subgroup could be a confounding factor. A maximum brainstem point dose ≥ 29.5 Gy was associated with a higher probability of bothersome facial numbness.
CONCLUSIONS: BED and physical dose were both predictive of pain relief and could be used as treatment planning goals for distal and proximal targets, respectively, while considering maximum brainstem point dose < 29.5 Gy as a potential constraint for bothersome numbness.
METHODS: This was a retrospective study of 871 patients with type 1 TN from 13 GKRS centers. Patient demographics, pain characteristics, treatment parameters, and outcomes were reviewed. BED was compared with prescription dose and other dosimetric factors for their predictive value.
RESULTS: The median age of the patients was 68 years, and 60% were female. Nearly 70% of patients experienced pain in the V2 and/or V3 dermatomes, predominantly on the right side (60%). Most patients had modified BNI Pain Intensity Scale grade IV or V pain (89.2%) and were taking 1 or 2 pain medications (74.1%). The median prescription dose was 80 Gy (range 62.5-95 Gy). The proximal trigeminal nerve was targeted in 77.9% of cases, and the median follow-up was 21 months (range 6-156 months). Initial pain relief (modified BNI Pain Intensity Scale grades I-IIIa) was noted in 81.8% of evaluable patients at a median of 30 days. Of 709 patients who achieved initial pain relief, 42.3% experienced at least one pain recurrence after GKRS at a median of 44 months, with 49.0% of these patients undergoing a second procedure. New-onset facial numbness occurred in 25.3% of patients after a median of 8 months. Age ≥ 63 years was associated with a higher probability of both initial pain relief and maintaining pain relief. A distal target location was associated with a higher probability of initial and long-term pain relief, but also a higher incidence of sensory dysfunction. BED ≥ 2100 Gy2.47 was predictive of pain relief at 30 days and 1 year for the distal target, whereas physical dose ≥ 85 Gy was significant for the proximal target, but the restricted range of BED values in this subgroup could be a confounding factor. A maximum brainstem point dose ≥ 29.5 Gy was associated with a higher probability of bothersome facial numbness.
CONCLUSIONS: BED and physical dose were both predictive of pain relief and could be used as treatment planning goals for distal and proximal targets, respectively, while considering maximum brainstem point dose < 29.5 Gy as a potential constraint for bothersome numbness.
摘要：
目的：最近的研究表明，生物有效剂量（BED）是伽玛刀放射外科（GKRS）治疗三叉神经痛（TN）后疼痛缓解和感觉功能障碍的重要相关因素。这项研究的目的是确定BED在预测接受GKRS作为第一程序的TN患者的预后方面是否优于处方剂量。
方法：这是一项来自13个GKRS中心的871例1型TN患者的回顾性研究。患者人口统计学，疼痛的特点，处理参数，并对结果进行了审查。将BED与处方剂量和其他剂量学因素进行了预测价值比较。
结果：患者的中位年龄为68岁，60%是女性。近70％的患者在V2和/或V3皮套中经历了疼痛，主要在右侧（60％）。大多数患者患有改良的BNI疼痛强度量表IV或V级疼痛（89.2％），并服用1或2种止痛药（74.1％）。中位处方剂量为80Gy（范围62.5-95Gy）。77.9%的病例靶向三叉神经近端,中位随访时间为21个月(6-156个月).在中位数为30天的81.8%的可评估患者中注意到初始疼痛缓解(改良的BNI疼痛强度量表等级I-IIIa)。在709名初步缓解疼痛的患者中，42.3％的患者在GKRS后经历了至少一次疼痛复发，中位时间为44个月，其中49.0%的患者接受第二次手术。中位时间为8个月后，有25.3％的患者出现新发面部麻木。年龄≥63岁与初始疼痛缓解和维持疼痛缓解的可能性较高相关。远端目标位置与初始和长期疼痛缓解的较高概率相关，而且感觉功能障碍的发生率也较高。BED≥2100Gy2.47可预测远端目标在30天和1年时疼痛缓解，而物理剂量≥85Gy对于近端目标是显著的，但本子组中BED值的限制范围可能是一个混杂因素.最大脑干点剂量≥29.5Gy与令人讨厌的面部麻木的可能性更高相关。
结论：BED和物理剂量均可预测疼痛缓解，可用作远端和近端目标的治疗计划目标。分别,同时考虑最大脑干点剂量<29.5Gy作为烦人麻木的潜在约束。
方法：这是一项来自13个GKRS中心的871例1型TN患者的回顾性研究。患者人口统计学，疼痛的特点，处理参数，并对结果进行了审查。将BED与处方剂量和其他剂量学因素进行了预测价值比较。
结果：患者的中位年龄为68岁，60%是女性。近70％的患者在V2和/或V3皮套中经历了疼痛，主要在右侧（60％）。大多数患者患有改良的BNI疼痛强度量表IV或V级疼痛（89.2％），并服用1或2种止痛药（74.1％）。中位处方剂量为80Gy（范围62.5-95Gy）。77.9%的病例靶向三叉神经近端,中位随访时间为21个月(6-156个月).在中位数为30天的81.8%的可评估患者中注意到初始疼痛缓解(改良的BNI疼痛强度量表等级I-IIIa)。在709名初步缓解疼痛的患者中，42.3％的患者在GKRS后经历了至少一次疼痛复发，中位时间为44个月，其中49.0%的患者接受第二次手术。中位时间为8个月后，有25.3％的患者出现新发面部麻木。年龄≥63岁与初始疼痛缓解和维持疼痛缓解的可能性较高相关。远端目标位置与初始和长期疼痛缓解的较高概率相关，而且感觉功能障碍的发生率也较高。BED≥2100Gy2.47可预测远端目标在30天和1年时疼痛缓解，而物理剂量≥85Gy对于近端目标是显著的，但本子组中BED值的限制范围可能是一个混杂因素.最大脑干点剂量≥29.5Gy与令人讨厌的面部麻木的可能性更高相关。
结论：BED和物理剂量均可预测疼痛缓解，可用作远端和近端目标的治疗计划目标。分别,同时考虑最大脑干点剂量<29.5Gy作为烦人麻木的潜在约束。
