Development of CdZnTe gamma camera for radioguided surgery

伽玛探针已被用于黑色素瘤和乳腺癌的前哨淋巴结活检。然而，伽马探针只能根据检测到的放射性强度提供放射性计数和可变音高音频输出。我们已经开发了一种小型半导体伽马相机（SSGC），可以将目标组织的大小，形状和位置可视化。本研究的目的是表征SSGC在转移性病变的放射引导手术中的性能，以及诊断其他适合与该原型成像系统相关的较小格式的疾病的性能。方法与设计：探测器头部由32 × 32碲化镉半导体阵列和专用集成电路（ASIC）和钨准直器组成。整个组件被封装在152毫米x 166毫米x 65毫米的铅壳中。有效视野为44.8 mm × 44.8 mm。采用两个直径为5 mm的球形Tc-99 m放射源，活度分别为0.15 MBq和100 MBq，模拟前哨淋巴结和注射部位。比较了该探测器与传统闪烁相机对这些焦点的相对可探测性。该原型还在患者身上探索了各种临床应用。结果：与传统的伽玛相机控制相比，SSGC在幻影研究中提供了更好的空间分辨率。使用15秒的采集时间，SSGC可以清晰地显示这两个焦点，而在可比条件下，使用传统系统无法轻松识别它们。初步临床试验发现，SSGC在多种组织（包括唾腺和甲状腺、颞下颌关节和前哨淋巴结）的疾病成像方面是成功的。结论：SSGC在疾病诊断和后续放射引导手术中具有重要的应用潜力。

Gamma probes have been used for sentinel lymph node biopsy in melanoma and breast cancer. However, gamma probes can only provide radioactivity counts and variable pitch audio output based on the intensity of the detected radioactivity. We have developed a small semiconductor gamma camera (SSGC) that allows the size, shape, and location of the target tissues to be visualized. The purpose of this study is to characterize the performance of the SSGC for radioguided surgery of metastatic lesions and for diagnosing other diseases amenable to the smaller-format associated with this prototype imaging system. Methods ＆ Design : The detector head was comprised of a 32 x 32 Cadmium Telluride semiconductor array and application-specific integrated circuit (ASIC) with a tungsten collimator. The entire assembly was encased in a lead housing measuring 152 mm x 166 mm x 65 mm. The effective visual field was 44.8 mm x 44.8 mm. Two spherical 5 mm diameter Tc-99 m radioactive sources having activities of 0.15 MBq and 100 MBq were used to simulate sentinel lymph nodes and injection site. The relative detectability of these foci was compared using the new detector and a conventional scintillation camera. Use of the prototype was also explored on patients in a variety of clinical applications. Results : The SSGC provided better spatial resolution on phantom studies than the conventional gamma camera control. Both foci could be visualized clearly by the SSGC using a 15-second acquisition time, whereas they could not be readily identified using the conventional system under comparable conditions. Preliminary clinical tests of the SSGC were found to be successful in imaging diseases in a variety of tissues including salivary and thyroid glands, temporomandibular joints, and sentinel lymph nodes. Conclusion : The SSGC has significant potential for use in diagnosing diseases and for facilitating subsequent radioguided surgery.