Department of Radiology, Gazi University School of Medicine, 06560, Ankara, Turkey.
Department of Neurosurgery, Gazi University School of Medicine, 06560, Ankara, Turkey.
Neuroradiology. 2024 Apr;66(4):609-620. doi: 10.1007/s00234-024-03296-0. Epub 2024 Feb 16.
To investigate the radiation-induced effects of Gamma Knife radiosurgery (GKRS) for sellar-parasellar tumors on optic pathways using DTI parameters within the first year after treatment.
Twenty-five patients with sellar-parasellar tumors underwent MRI before and 3 months after GKRS, including T1WI, DTI, T2WI. Moreover, 21 patients underwent follow-up DTI 6-8 months after radiosurgery. ROIs were set on optic nerves, optic radiations, and control localizations; DTI parameters for each were calculated. Pre- and post-radiosurgery differences in DTI values were statistically compared and assessed with respect to tumor size changes.
Following GKRS, DTI parameters, notably ADC, FA, and RD, showed statistically significant changes in optic nerves and anterior optic radiations. DTI changes were more significant in the group of cases with tumor shrinkage. In this group, DTI of the anterior optic radiations further deteriorated 3 months post-GKRS, whereas acute changes in DTI parameters of the optic nerves resolved within 6-8 months. DTI of central and posterior optic radiations did not differ significantly following radiosurgery; 6-8 months after radiosurgery, visual function was stable in 14 (56%) patients and improved in 11 (44%), showing no correlation with tumor size changes or DTI parameters.
White Matter (WM) injury in the optic pathways can be induced by Gamma Knife radiosurgery targeted to sellar and parasellar tumors. Following GKRS, microstructural abnormalities occurred in the optic radiations as well as the optic nerves within the first post-treatment year. Our findings could support modifications to radiosurgical treatment strategies to minimize the risk of permanent WM injury.
使用治疗后 1 年内的 DTI 参数，研究伽玛刀放射外科（GKRS）治疗鞍旁肿瘤对视路的辐射诱导效应。
25 例鞍旁肿瘤患者在 GKRS 前后 3 个月进行 MRI 检查，包括 T1WI、DTI、T2WI。此外，21 例患者在放射外科治疗后 6-8 个月进行了随访 DTI。在视神经、视辐射和对照部位设置 ROI，计算每个部位的 DTI 参数。对治疗前后 DTI 值的差异进行统计学比较，并评估其与肿瘤大小变化的关系。
GKRS 后，视神经和前部视辐射的 DTI 参数，尤其是 ADC、FA 和 RD，表现出显著的统计学变化。在肿瘤缩小的病例组中，DTI 变化更为显著。在该组中，GKRS 后 3 个月前部视辐射的 DTI 进一步恶化，而视神经的 DTI 参数急性变化在 6-8 个月内得到解决。放射外科治疗后视辐射的中央和后部 DTI 无显著差异；放射外科治疗后 6-8 个月，14 例（56%）患者的视力功能稳定，11 例（44%）患者视力改善，与肿瘤大小变化或 DTI 参数无相关性。
针对鞍旁肿瘤的伽玛刀放射外科治疗可导致视路的白质（WM）损伤。GKRS 后，视神经和视辐射的微观结构异常发生在治疗后 1 年内。我们的研究结果可以支持对放射外科治疗策略的修改，以最大程度地降低 WM 损伤的风险。
