Górska-Chrzastek Magdalena, Grzelak Piotr, Bieńkiewicz Małgorzata, Tybor Krzysztof, Zakrzewska Edyta, Mikołajczak Renata, Stefańczyk Ludomir, Kuśmierek Jacek
Nuclear Medicine Department of Medical University, Łódź, Poland.
Nucl Med Rev Cent East Eur. 2004;7(2):135-41.
Early detection and diagnostic differentiation of neoplastic tissue from necrotic changes and scars following the treatment of cerebral gliomas is essential for determining further therapy and prognosis. The primary technique used for the diagnostics of recurrent neoplastic growth is the magnetic resonance imaging (MRI), which in some cases, however, does not allow one to identify the character of cerebral lesions. Recently, MRI has been supplemented with single-photon emission computed tomography (SPECT) or positron emission tomography (PET) employing radiolabelled amino acids. e.g. tyrosine or methionine. The aim of the project was to assess the diagnostic potential of SPECT when iodine-131 alpha-methyl tyrosine (IMT), a Polish make of radiopharmaceutical (OBRI--POLATOM, Otwock-Rwierk, Poland), was applied. The use of 131I as a substitute for the more costly, imported iodine-123 has been justified in view of the nature and significance of the diagnostic problem on the one hand, and the possibility of 131-iodine application on a larger scale in CEE countries, on the other.
MRI and SPECT were performed in 24 patients with a history of surgical treatment and radiotherapy of cerebral glioma (WHO grade II/IV). A SPECT was carried out 15 min after an i.v. injection of 74-111 MBq IMT. The tomograms were evaluated visually and in quantitative terms. The fused SPET/MR images were also analyzed. The obtained results were verified against histopathological findings, control MRI examinations and the clinical course of disease within 7-28 months of monitoring.
In 19 patients, an increased IMT uptake indicative of a recurrent tumour was found, and the presence of the tumour was confirmed. In five patients no hot spots were detected which would indicate the neoplastic growth and verification did not provide any evidence for relapse.
The examination employing iodine-131 IMT made it possible to confirm or exclude tumour recurrence in all the subjects, also in the cases when the CT/MR images were inconclusive. The MRI/SPECT fusion made it possible to more accurately identify the location of tumour recurrence as well as determine the area for spectroscopic MR analysis, for stereotactic biopsy and radiotherapy.
脑胶质瘤治疗后，早期检测肿瘤组织并将其与坏死改变及瘢痕进行鉴别诊断，对于确定进一步治疗方案和判断预后至关重要。用于诊断复发性肿瘤生长的主要技术是磁共振成像（MRI），然而在某些情况下，MRI无法确定脑病变的性质。最近，MRI已辅以使用放射性标记氨基酸（如酪氨酸或蛋氨酸）的单光子发射计算机断层扫描（SPECT）或正电子发射断层扫描（PET）。该项目的目的是评估应用波兰生产的放射性药物碘-131α-甲基酪氨酸（IMT，OBRI - POLATOM，波兰奥托克-维尔克）时SPECT的诊断潜力。鉴于诊断问题的性质和重要性，以及在中东欧国家更广泛应用碘-131的可能性，使用131I替代成本更高的进口碘-123是合理的。
对24例有脑胶质瘤手术治疗和放疗史（WHO分级II/IV级）的患者进行了MRI和SPECT检查。静脉注射74 - 111 MBq IMT后15分钟进行SPECT检查。对断层扫描进行了视觉和定量评估。还分析了融合的SPET/MR图像。将所得结果与组织病理学结果、对照MRI检查以及7 - 28个月监测期内的疾病临床进程进行了验证。
19例患者中发现IMT摄取增加，提示肿瘤复发，肿瘤存在得到证实。5例患者未检测到提示肿瘤生长的热点，验证未提供任何复发证据。
使用碘-131 IMT进行检查能够在所有受试者中确认或排除肿瘤复发，即使在CT/MR图像不明确的情况下也是如此。MRI/SPECT融合使得能够更准确地识别肿瘤复发的位置，并确定用于磁共振波谱分析、立体定向活检和放疗的区域。
