Todorović-Tirnanić Mila, Kaemmerer Daniel, Prasad Vikas, Hommann Merten, Baum Richard P
Faculty of Medicine, University of Belgrade, Belgrade, Serbia.
Recent Results Cancer Res. 2013;194:487-96. doi: 10.1007/978-3-642-27994-2_28.
The aim of this chapter is to present the results of the first intraoperative somatostatin receptor detection after peptide receptor radionuclide therapy (PRRNT) with (90)Y- and (177)Lu-DOTATOC using a handheld gamma probe and comparison with the findings of preoperative (68)Ga-DOTATOC PET/CT in a patient with a metastatic neuroendocrine tumor (NET) of the ileum.
A 56-year-old female patient, treated twice by PRRNT, was admitted for the third cycle and subsequent surgery. Before operation, the following studies were performed for restaging after the second cycle of PRRNT: (99m)Tc-MAG3 + TER, (99m)Tc-DTPA + GFR, abdominal ultrasonography, MRI of the abdomen, (68)Ga-DOTATOC PET/CT as well as (18)F-fluoride PET/CT. Serum tumor markers were measured before and after PRRNT. Tandem PRRNT was performed using 3000 MBq (90)Y-DOTATOC and 6000 MBq (177)Lu-DOTATOC. Whole-body scintigrams were obtained at 23 and 43 h. Five days after PRRNT, the patient was operated using a handheld gamma probe. Immunohistochemistry and histopathology of the resected tissue were performed.
Tandem PRRNT was very well tolerated by the patient. Before PRRNT, (68)Ga-DOTATOC PET/CT revealed the primary tumor in the ileocoecal region as well as bilobular liver metastases and a right iliac bone lesion (osteoblastic on (18)F-fluoride PET/CT). Compared with the previous findings, there was good therapy response (partial remission of the tumor lesions). No nephrotoxicity was observed. Serum chromogranin A (836 μg/l, n < 100) and serotonin (852 μg/l, n < 200) were strongly elevated. Posttherapy scans showed intense uptake in metastases and the primary tumor. Intraoperative gamma probe detected-in addition to the known lesions-bilateral ovarian metastases not visualized by (68)Ga-DOTATOC PET/CT. Bilateral adnexectomy, right hemicolectomy, excision of hepatic metastases in S3, and partial resection of peritoneum were performed. Histopathology confirmed metastases in both ovaries.
Gamma probe-guided surgery after (177)Lu PRRNT is feasible and appears to be more sensitive than (68)Ga-DOTATOC PET/CT. This technique might aid the surgeon in achieving more complete tumor resection through intraoperative detection of very small lesions (<5 mm) directly after PRRNT.
本章旨在介绍在一名患有回肠转移性神经内分泌肿瘤（NET）的患者中，使用手持式γ探测器对肽受体放射性核素治疗（PRRNT）后首次术中生长抑素受体检测的结果，并与术前（68）Ga-DOTATOC PET/CT的结果进行比较。PRRNT使用（90）Y-和（177）Lu-DOTATOC进行。
一名56岁女性患者，接受过两次PRRNT治疗，因第三次治疗周期及后续手术入院。术前，在PRRNT的第二个周期后进行了以下再分期检查：（99m）Tc-MAG3 + TER、（99m）Tc-DTPA + GFR、腹部超声、腹部MRI、（68）Ga-DOTATOC PET/CT以及（18）F-氟化物PET/CT。在PRRNT前后测量血清肿瘤标志物。使用3000 MBq（90）Y-DOTATOC和6000 MBq（177）Lu-DOTATOC进行串联PRRNT。在23小时和43小时获得全身闪烁扫描图像。PRRNT后5天，使用手持式γ探测器对患者进行手术。对切除组织进行免疫组织化学和组织病理学检查。
患者对串联PRRNT耐受性良好。在PRRNT前，（68）Ga-DOTATOC PET/CT显示回盲部区域的原发性肿瘤以及双侧肝叶转移和右侧髂骨病变（在（18）F-氟化物PET/CT上为成骨细胞性）。与之前的结果相比，有良好的治疗反应（肿瘤病变部分缓解）。未观察到肾毒性。血清嗜铬粒蛋白A（836μg/l，n < 100）和血清素（852μg/l，n < 200）显著升高。治疗后扫描显示转移灶和原发性肿瘤有强烈摄取。术中γ探测器除了检测到已知病变外，还发现了（68）Ga-DOTATOC PET/CT未显示的双侧卵巢转移。进行了双侧附件切除术、右半结肠切除术、S3肝转移灶切除术以及部分腹膜切除术。组织病理学证实双侧卵巢有转移。
（177）Lu PRRNT后γ探测器引导下的手术是可行的，并且似乎比（68）Ga-DOTATOC PET/CT更敏感。该技术可能有助于外科医生在PRRNT后直接通过术中检测非常小的病变（<5mm）实现更完整的肿瘤切除。
