Department of Neurological Surgery, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA.
Rose Ella Burkhardt Brain Tumor & Neuro-Oncology Center, Cleveland Clinic, Cleveland, OH, USA.
Acta Neurochir (Wien). 2021 Apr;163(4):1013-1019. doi: 10.1007/s00701-021-04738-x. Epub 2021 Feb 3.
Radiosurgery is a well-established treatment for vestibular schwannomas (VSs), but it is often difficult to identify which tumors will respond to treatment. We sought to determine whether pretreatment or posttreatment tumor apparent diffusion coefficient (ADC) values could predict tumor control in patients undergoing Gamma Knife radiosurgery (GKRS) and whether these values could differentiate between cases of pseudoprogression and cases of true progression in the early posttreatment period.
We retrospectively identified patients who underwent GKRS for solid VSs between June 2008 and November 2016 and who had a minimum follow-up of 36 months. Pretreatment and posttreatment minimum, mean, and maximum ADC values were measured for the whole tumor volume and were compared between patients with tumor control and those with tumor progression. In patients with early posttreatment tumor enlargement, ADC values were compared between patients with pseudoprogression and those with true progression.
Of the 44 study patients, 34 (77.3%) demonstrated tumor control at final follow-up. Patients with tumor control had higher pretreatment minimum (1.35 vs 1.09; p = 0.008), mean (1.80 vs 1.45; p = 0.004), and maximum (2.41 vs 1.91; p = 0.011) ADC values than patients with tumor progression. ADC values did not differ between patients with pseudoprogression and those with true progression at early posttreatment follow-up.
ADC values may be helpful in predicting response to GKRS in patients with solid VSs but cannot predict which tumors will undergo pseudoprogression. Patients with higher pretreatment ADC values may be more likely to demonstrate posttreatment tumor control.
放射外科是治疗前庭神经鞘瘤（VSs）的一种成熟的治疗方法，但通常很难确定哪些肿瘤对治疗有反应。我们试图确定伽玛刀放射外科治疗（GKRS）前后肿瘤表观扩散系数（ADC）值是否可以预测肿瘤控制，并确定这些值是否可以区分治疗后早期的假性进展和真性进展病例。
我们回顾性地确定了 2008 年 6 月至 2016 年 11 月期间接受 GKRS 治疗的实体 VS 患者，且随访时间至少为 36 个月。测量整个肿瘤体积的治疗前和治疗后最小、平均和最大 ADC 值，并比较肿瘤控制患者和肿瘤进展患者之间的差异。在治疗后早期肿瘤增大的患者中，比较假性进展和真性进展患者的 ADC 值。
在 44 名研究患者中，34 名（77.3%）在最终随访时肿瘤得到控制。肿瘤控制患者的治疗前最小 ADC 值（1.35 比 1.09；p = 0.008）、平均 ADC 值（1.80 比 1.45；p = 0.004）和最大 ADC 值（2.41 比 1.91；p = 0.011）均高于肿瘤进展患者。在治疗后早期随访时，假性进展患者和真性进展患者的 ADC 值无差异。
ADC 值可能有助于预测实体 VS 患者 GKRS 治疗的反应，但不能预测哪些肿瘤会发生假性进展。治疗前 ADC 值较高的患者可能更有可能在治疗后显示肿瘤控制。
