Benghiat H, Heyes G, Nightingale P, Hartley A, Tiffany M, Spooner D, Geh J I, Cruickshank G, Irving R M, Sanghera P
Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
Hall-Edwards Radiotherapy Research Group, The Cancer Centre, Queen Elizabeth Hospital, Birmingham, UK.
Clin Oncol (R Coll Radiol). 2014 Jun;26(6):309-15. doi: 10.1016/j.clon.2014.02.008. Epub 2014 Mar 11.
To evaluate non-auditory toxicity and local control after linear accelerator stereotactic radiosurgery (SRS) for the treatment of vestibular schwannomas.
The institutional policy was to use SRS for radiologically progressing vestibular schwannomas. Case notes and plans were retrospectively reviewed for all patients undergoing SRS for vestibular schwannomas between September 2002 and June 2012. All patients were surgically immobilised using a BrainLab stereotactic head frame. The treatment plan was generated using BrainLab software (BrainScan 5.03). The aim was to deliver 12 Gy to the surface of the target with no margin. Patients with a minimum of 12 months of follow-up were included for toxicity and local control assessment. Radiological progression was defined as growth on imaging beyond 2 years of follow-up. Overall local control was defined in line with other series as absence of surgical salvage.
Ninety-nine patients were identified. Two patients were lost to follow-up. After a median follow-up interval of 2.4 years, the actuarial radiological progression-free survival at 3 years was 100% and overall local control was also 100%. However, two patients progressed radiologically at 3.3 and 4.5 years, respectively. Twenty-one of 97 (22%) evaluable patients suffered trigeminal toxicity and this was persistent in 8/97 (8%). Two of 97 (2%) suffered long-term facial nerve toxicity (one with associated radiological progression causing hemi-facial spasm alone). One of 97 (1%) required intervention for obstructive hydrocephalus. No statistically significant dosimetric relationship could be shown to cause trigeminal or facial nerve toxicity. However, 7/8 patients with persistent trigeminal nerve toxicity had tumours in contact with the trigeminal nerve.
SRS delivering 12 Gy using a linear accelerator leads to high local control rates, but only prospective evaluation will fully establish short-term toxicity. In this study, persistent trigeminal toxicity occurred almost exclusively in patients whose tumour was in contact with the trigeminal nerve.
评估直线加速器立体定向放射外科治疗（SRS）前庭神经鞘瘤后的非听觉毒性和局部控制情况。
机构政策是对影像学进展的前庭神经鞘瘤采用SRS治疗。回顾性分析2002年9月至2012年6月期间所有接受SRS治疗前庭神经鞘瘤患者的病历和治疗计划。所有患者均使用BrainLab立体定向头架进行手术固定。使用BrainLab软件（BrainScan 5.03）生成治疗计划。目标是在不设边缘的情况下，将12 Gy的剂量照射到靶区表面。纳入随访至少12个月的患者进行毒性和局部控制评估。放射学进展定义为随访2年以上影像学显示肿瘤生长。总体局部控制按照其他系列的定义为无需手术挽救。
共识别出99例患者。2例失访。中位随访间隔2.4年后，3年时精算无放射学进展生存率为100%，总体局部控制率也为100%。然而，2例患者分别在3.3年和4.5年出现放射学进展。97例可评估患者中有21例（22%）出现三叉神经毒性，其中8/97例（8%）为持续性。97例中有2例（2%）出现长期面神经毒性（1例伴有放射学进展，单独导致半面痉挛）。97例中有1例（1%）因梗阻性脑积水需要干预。未发现导致三叉神经或面神经毒性的剂量学关系具有统计学意义。然而，8例持续性三叉神经毒性患者中有7例肿瘤与三叉神经接触。
使用直线加速器给予12 Gy的SRS可实现较高的局部控制率，但只有前瞻性评估才能全面确定短期毒性。在本研究中，持续性三叉神经毒性几乎仅发生在肿瘤与三叉神经接触的患者中。
