Baradaran-Salimi Kian, Karimzadeh Amir, Voges Berthold, Apostolova Ivayla, Sauvigny Thomas, Simova Olga, Lanz Michael, Klutmann Susanne, Stodieck Stefan, Meyer Philipp T, Buchert Ralph
Department of Diagnostic and Interventional Radiology and Nuclear Medicine, University Medical Center Hamburg-Eppendorf, Martinistr. 52, 20246, Hamburg, Germany.
Department of Neurology and Epileptology, Protestant Hospital Alsterdorf, Hamburg, Germany.
EJNMMI Res. 2024 Sep 12;14(1):83. doi: 10.1186/s13550-024-01149-8.
Ictal brain perfusion SPECT provides higher sensitivity for the identification of the epileptic seizure onset zone (SOZ) than interictal SPECT. However, ictal SPECT is demanding due to the unpredictable waiting period for the next seizure to allow for ictal tracer injection. Thus, starting with an interictal scan and skipping the ictal scan if the interictal scan provides a SOZ candidate with high confidence could be an efficient approach. The current study estimated the rate of high-confidence SOZ candidates and the false lateralization rate among them for interictal and ictal SPECT.
177 patients (48% females, median age 38y, interquartile range 27-48y) with ictal and interictal SPECT acquired with Tc-HMPAO (n = 141) or -ECD (n = 36) were included retrospectively. The vast majority of the patients was suspected to have temporal lobe epilepsy. Visual interpretation of the SPECT data was performed independently by 3 readers in 3 settings: "interictal only" (interictal SPECT and statistical hypoperfusion map), "ictal only" (ictal SPECT and hyperperfusion map), and "full" setting (side-by-side interpretation of ictal and interictal SPECT including statistical maps and SISCOM analysis). The readers lateralized the SOZ (right, left, none) and characterized their confidence using a 5-score. A case was considered "lateralizing with high confidence" if all readers lateralized to the same hemisphere with at least 4 of 5 confidence points. Lateralization of the SOZ in the "full" setting was used as reference standard.
The proportion of "lateralizing with high confidence" cases was 4.5/31.6/38.4% in the "interictal only"/"ictal only"/"full" setting. One (12.5%) of the 8 cases that were "lateralizing with high confidence" in the "interictal only" setting lateralized to the wrong hemisphere. Among the 56 cases that were "lateralizing with high confidence" in the "ictal only" setting, 54 (96.4%) were also lateralizing in the "full" setting, all to the same hemisphere.
Starting brain perfusion SPECT in the presurgical evaluation of epilepsy with an interictal scan to skip the ictal scan in case of a high-confidence interictal SOZ candidate is not a useful approach. In contrast, starting with an ictal scan to skip the interictal scan in case of a high-confidence ictal SOZ candidate can be recommended.
发作期脑灌注单光子发射计算机断层扫描（SPECT）在识别癫痫发作起始区（SOZ）方面比发作间期SPECT具有更高的灵敏度。然而，发作期SPECT要求较高，因为下一次发作以便进行发作期示踪剂注射的等待期不可预测。因此，从发作间期扫描开始，如果发作间期扫描能提供高可信度的SOZ候选区，则跳过发作期扫描可能是一种有效的方法。本研究估计了发作间期和发作期SPECT中高可信度SOZ候选区的比例及其假侧别率。
回顾性纳入177例患者（48%为女性，中位年龄38岁，四分位间距27 - 48岁），这些患者进行了用锝-六甲基丙二胺肟（Tc-HMPAO，n = 141）或 - 乙撑双半胱氨酸（ECD，n = 36）进行的发作期和发作间期SPECT检查。绝大多数患者疑似患有颞叶癫痫。3名阅片者在3种情况下独立对SPECT数据进行视觉解读：“仅发作间期”（发作间期SPECT和统计性灌注减低图）、“仅发作期”（发作期SPECT和灌注增加图）以及“完整”情况（发作期和发作间期SPECT并排解读，包括统计图和SISCOM分析）。阅片者对SOZ进行侧别（右侧、左侧、无）并使用5分制对其信心程度进行评估。如果所有阅片者都将至少4分的信心值侧别到同一半球，则该病例被认为“高可信度侧别”。以“完整”情况下SOZ的侧别结果作为参考标准。
在“仅发作间期”/“仅发作期”/“完整”情况下，“高可信度侧别”病例的比例分别为4.5%/31.6%/38.4%。在“仅发作间期”情况下“高可信度侧别”的8例病例中有1例（12.5%）侧别到错误的半球。在“仅发作期”情况下“高可信度侧别”的56例病例中，有54例（96.4%）在“完整”情况下也有侧别，且都在同一半球。
在癫痫术前评估中，以发作间期扫描开始进行脑灌注SPECT，如果发作间期有高可信度的SOZ候选区则跳过发作期扫描，这不是一种有用的方法。相比之下，建议以发作期扫描开始，如果发作期有高可信度的SOZ候选区则跳过发作间期扫描。
