Scintigraphy and SPECT/CT of Sentinel Lymph Nodes for Planning of Operative Intervention in Breast Cancer

Abstract

Purpose: To increase the effectiveness and quality of surgery treatment for patients with early stages of breast cancer.
 Material and methods: Since 2016, 25 patients with breast cancer were examined and went through surgery. A lymphotropic colloidal radiopharmaceutical labeled with 99mTc was used; it was administered (150 MBq) the day before the operation. 20 patients received this injection intradermally into periareolar zone, 4 patients received it peritumourally (under control of ultrasound), 1 – paratumorally. Lymphoscintigraphy was performed 3 hours after injection, the images were acquired using dual-head gamma camera Symbia E (Siemens, Germany). A static multiplanar imaging (scintigraphy) (anterior, posterior, lateral projections) was performed for the sentinel nodes (SN) mapping. 25 planar examinations were performed. In 3 cases additional SPECT/CT study was performed using a hybrid SPECT/CT Symbia T2 (Siemens, Germany). Surgical intervention was done on the next day after scintigraphy. During the surgery the hand-held gamma probe NEO 2000 (Johnson & Johnson, USA) was used to localize radioactivity. The lymph nodes with the highest count (hot lymph nodes) were removed and sent for immediate histological examination. The results of immediate histological examination were evaluated again during next studies of gross specimen and slides.
 Results: During scintigraphy studies planar and SPECT/CT, 26 SN were detected in 20 women (80 %). In 15 patients only one SN lymph node was found, in 4 patients – 2, and in one case 3 SN were found. Intraoperative search of SN and immediate histological examination was conducted in 22 cases, 33 SN were found, while during planar scintigraphy only 26. In three cases, after histological examination (after obtaining examination results), patient surveillance was changed, these patients did not undergo through intraoperative radiometry and a decision was to conduct a one-stage mastectomy with regional lymphadenectomy. 10 out of 22 patients which underwent intraoperative radiometry and sentinel node biopsy, with immediate histological examination had metastases in the removed nodes, therefore lymphadenectomy had been performed. In the rest 12 patients after immediate histological examination of SN no evidence of tumor growth was found, thus lymphadenectomy was not performed. In case of three patients which did not undergo through intraoperative radiometry, lymphadenectomy was performed and after histological examination only two patients had tumor-involved SN, and one patient was clear. All intraoperative results were confirmed with next follow-up histological examinations. In 5 out of 25 patients (20 %) sentinel nodes were not founded. In these 5 cases during follow up period metastases were found in regional lymph nodes, and one patient had tumor emboli in lymphatic vessels, this considered being the cause of negative scintigraphy result. In 12 cases out of 25 (48 %) it was possible to minimize surgical management, and 13 (52 %) undergo lymphadenectomy.
 Conclusion: 1) The integration of SPECT/CT method of sentinel nodes search allows to plan an optimal surgical management, and can positively affect the long-term follow-up result of treatment of patients with breast cancer, and improve the quality of life. 2) The sensitivity and positive prognostic value (PPV) of planar scintigraphy and intraoperative radiometry of searching for SN are 80, 100 and 73.3, 100 %, respectively. 3) Thanks to the method of lymphoscintigraphy, 12 (48 %) of 25 women it was possible to minimize surgical management without lymphadenectomy.