Máté Lázár

Importance of Sentinel Lymph Node Biopsy in Surgical Therapy of in situ Breast Cancer

The aim of this retrospective study was to determine the rate of sentinel lymph node (SLN) positivity in patients with a final diagnosis of ductal in situ cancer (DCIS) of the breast. Between October 2002 and January 2007, 57 patients with DCIS underwent wide excision after radio-guided lesion localization; 53 of them (53/57, 93%) had participated in simultaneous SLN mapping. SLNs were analysed by 250-micron step-sectioning with haematoxylin and eosin staining and immunohistochemical evaluation. The histologic investigation verified pure breast DCIS in 44 cases (44/57, 77.2%), DCIS with microinvasion in eight cases (8/57, 14%) and lobular in situ breast cancer in five cases (5/57, 8.8%). SLNs were identified in 49 cases (49/53, 92.5%) and removed in 48 cases (48/53, 90.6%), i.e. an average of 1.6 SLNs per patient. In four patients (4/53, 7.6%), the SLN biopsy was unsuccessful because of the failure of the radiocolloid substance to migrate. In these cases, axillary sampling was performed. In one case (1/53, 1.9%), only a parasternal SLN was detected; this was not removed. Histologic analysis of the SLNs and the axillary lymph nodes with haematoxylin and eosin or cytokeratin immunohistochemistry did not prove the presence of metastases. The international data and our present results suggest that routine SLN biopsy is not to be recommended in pure DCIS cases. If the final histology verifies an invasive or microinvasive tumour, or if mastectomy is to be performed, SLN mapping is suggested.

Prospective evaluation of thallium-201 reinjection in single-vessel coronary patients undergoing coronary bypass surgery

Twenty-two patients with single-vessel left anterior descending coronary artery disease were investigated by means of dipyridamole stress thallium-201 myocardial perfusion scintigraphy, using single photon emission tomography (SPET), 1 week before and 2–5 weeks after coronary bypass surgery. The dose of dipyridamole was 0.56 mg/kg, and the injected activity of 201T1 was 74 MBq. Before surgery, and after completion of the redistribution study, a further 37 MBq of 201T1 was injected. Ten minutes and 1 h later, repeated SPET imaging were performed. SPET images were evaluated both subjectively and semiquantitatively, using a five-grade segmental defect score system, with higher scores for more severe perfusion defects. Before surgery, the 3-h redistribution images revealed complete or partial persistence of the perfusion defects in all patients. On the images taken 10 min after reinjection, these defects were completely filled in four cases, and partially filled in ten cases. Further positive changes were observed on the 1-h post-reinjection images in four cases. Three of the 1-h post-reinjection images exhibited a paradox redistribution. The stress images after surgery corresponded well to the 201T1 distribution on the preoperative 1-h post-reinjection images in 11 cases. The average of the segmental defect severity scores was 17.0 after stress, 10.1 at rest, 7.1 10 min after reinjection and 6.4 1 h after reinjection. After surgery, the average of both the post-stress and the 3-h redistribution scores was 3.1. The correlation coefficients between the segmental scores of the postoperative resting study and the preoperative 3-h resting and the 10-min and 1-h post-reinjection studies were 0.72, 0.69 and 0.78, respectively. It is concluded that post-reinjection 201T1 images before surgery are good predictors of myocardial perfusion after revascularization. The best results are obtained if imaging is performed 1 h after reinjection.