Abstract：
BACKGROUND: Patchy alopecia is a common adverse effect of stereotactic radiosurgery (SRS) on the calvarium and/or scalp, yet no guidelines exist for its prevention. This study aims to investigate the incidence and outcomes of patchy alopecia following SRS for patients with calvarial or scalp lesions and establish preventive guidelines.
METHODS: The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months.
RESULTS: Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found.
CONCLUSIONS: In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.
METHODS: The study included 20 patients who underwent CyberKnife SRS for calvarial or scalp lesions, resulting in a total of 30 treated lesions. SRS was administered as a single fraction for 8 lesions and hypofractionated for 22 lesions. The median SRS target volume was 9.85 cc (range: 0.81-110.7 cc), and the median prescription dose was 27 Gy (range: 16-40 Gy), delivered in 1-5 fractions (median: 3). The median follow-up was 15 months.
RESULTS: Among the 30 treated lesions, 11 led to patchy alopecia, while 19 did not. All cases of alopecia resolved within 12 months, and no patients experienced other adverse radiation effects. Lesions resulting in alopecia exhibited significantly higher biologically effective dose (BED) and single-fraction equivalent dose (SFED) on the overlying scalp compared to those without alopecia. Patients with BED and SFED exceeding 60 Gy and 20 Gy, respectively, were 9.3 times more likely to experience patchy alopecia than those with lower doses. The 1-year local tumor control rate for the treated lesions was 93.3%. Chemotherapy was administered for 26 lesions, with 11 lesions receiving radiosensitizing agents. However, no statistically significant difference was found.
CONCLUSIONS: In summary, SRS is a safe and effective treatment for patients with calvarial/scalp masses regarding patchy alopecia near the treated area. Limiting the BED under 60 Gy and SFED under 20 Gy for the overlying scalp can help prevent patchy alopecia during SRS treatment of the calvarial/scalp mass. Clinicians can use this information to inform patients about the risk of alopecia and the contributing factors.
摘要：
背景：斑片性脱发是立体定向放射外科（SRS）对颅骨和/或头皮的常见不良反应，然而，没有预防它的指导方针。这项研究旨在调查SRS后颅骨或头皮病变患者斑片状脱发的发生率和结果，并建立预防指南。
方法：该研究包括20例接受射波刀SRS治疗颅骨或头皮病变的患者，导致总共30个治疗的病变。SRS作为8个病变的单个部分施用，而22个病变的小部分施用。SRS目标体积中位数为9.85cc（范围：0.81-110.7cc），中位处方剂量为27Gy（范围：16-40Gy），以1-5个分数递送（中位数：3）。中位随访时间为15个月。
结果：在30个治疗的病变中，11导致斑驳脱发，19没有。所有脱发病例在12个月内解决，并且没有患者经历其他不良辐射影响。与没有脱发的患者相比，导致脱发的病变在上覆头皮上表现出明显更高的生物有效剂量（BED）和单部分等效剂量（SFED）。BED和SFED超过60Gy和20Gy的患者，分别,与低剂量的患者相比，发生斑片状脱发的可能性要高9.3倍。治疗病灶的1年局部肿瘤控制率为93.3%。对26个病灶进行化疗,11个病灶接受放射增敏剂。然而,差异无统计学意义。
结论：总之，对于在治疗区域附近有斑片状脱发的颅骨/头皮肿块患者，SRS是一种安全有效的治疗方法。对于上覆的头皮，将BED限制在60Gy以下，将SFED限制在20Gy以下，可以帮助预防SRS治疗颅骨/头皮肿块期间的斑片状脱发。临床医生可以使用这些信息来告知患者脱发的风险和影响因素。
方法：该研究包括20例接受射波刀SRS治疗颅骨或头皮病变的患者，导致总共30个治疗的病变。SRS作为8个病变的单个部分施用，而22个病变的小部分施用。SRS目标体积中位数为9.85cc（范围：0.81-110.7cc），中位处方剂量为27Gy（范围：16-40Gy），以1-5个分数递送（中位数：3）。中位随访时间为15个月。
结果：在30个治疗的病变中，11导致斑驳脱发，19没有。所有脱发病例在12个月内解决，并且没有患者经历其他不良辐射影响。与没有脱发的患者相比，导致脱发的病变在上覆头皮上表现出明显更高的生物有效剂量（BED）和单部分等效剂量（SFED）。BED和SFED超过60Gy和20Gy的患者，分别,与低剂量的患者相比，发生斑片状脱发的可能性要高9.3倍。治疗病灶的1年局部肿瘤控制率为93.3%。对26个病灶进行化疗,11个病灶接受放射增敏剂。然而,差异无统计学意义。
结论：总之，对于在治疗区域附近有斑片状脱发的颅骨/头皮肿块患者，SRS是一种安全有效的治疗方法。对于上覆的头皮，将BED限制在60Gy以下，将SFED限制在20Gy以下，可以帮助预防SRS治疗颅骨/头皮肿块期间的斑片状脱发。临床医生可以使用这些信息来告知患者脱发的风险和影响因素。
