SPECT-fused 3D-CT mammary lymphography for endoscopic sentinel node biopsy.

Abstract

e11041 Background: The endoscopic surgery for the breast diseases has been proven safe and aesthetic, and named as video- assisted breast surgery (VABS). We also applied it for the sentinel node (SN) biopsy. It needs only 1 cm-long skin incision and a narrow tunnel to SN. However, it sometimes has difficulty in detecting the dye-stained node. The radioisotope (RI) may not be uptaken by true SN. We firstly succeeded to fuse the single photon emission computed tomography (SPECT) with 3D-CT mammary lymphography (LG). It can show the detailed position of all SN with or without RI uptake. Methods: 3D-CT LG was performed to mark SN on the skin. Above the tumor and near the areola, 2 mL of Iopamidol 300 was injected subcutaneously. Images of CT scan were taken at 1 and 3 minutes after injection to produce a 3D image of lymph ducts and nodes. For the lymphoscintigraphy, 99mTc phytate 74mBq was injected, and SPECT was taken after 2 hours. We fused it with 3D-CT LG. SN biopsy was performed by dye and RI method The skin incision was made 1 cm long in the axilla on the marked position. The endoscopic view was made through the optical trocar Visiport and showed stained lymph ducts and SNs, which can be navigated by the RI detector probe. Results: We have performed VABS on 260 patients, SN biopsy by the dye-staining method on 50 patients, with 3D-CT LG on 160 patients, and SPECT fused 3D-CT LG on 20 patients. All RI positive SNs coincided with 3D-CT LG detected SNs. We could detect their position on the axillary lymphatic mapping by the RI detector probe during surgery. The average sampled number of SN was 2.3. The dye-negative SN and RI-negative SN could be removed endoscopically. The SN metastases were 45 (28%). The other non-SN of axillary nodes could be observed. There was no false negative study. The wound scars were inconspicuous and aesthetic. Conclusions: SPECT-fused 3D-CT LG facilitates the endoscopic SN biopsy, which is aesthetic and less invasive. No significant financial relationships to disclose.