Predicting sentinel lymph node metastasis in breast cancer with lymphoscintigraphy.

OBJECTIVE: Lymphoscintigraphy is an effective method for detecting sentinel lymph nodes (SLNs). However, the rate and degree of SLN detection is not uniform. We quantified SLNs detected with lymphoscintigraphy, and investigated correlations with factors that may influence detection. We then attempted to predict SLN metastasis from lymph node counts, comparing the predictions to subsequent biopsy results. METHODS: We assessed lymph node counts in 100 breast cancer patients in whom a single SLN was detected with a fixed lymphoscintigraphy procedure. We examined correlations between the counts and factors known to influence lymphoscintigraphic SLN detection (age, body mass index, tumor size, and presence or absence of metastasis), and determined reference values (lymph node counts of 10.0, 19.4 and 53.0) which were used to predict SLN metastasis in 100 subsequent patients. The predictions were then compared with the SLN biopsy findings. RESULTS: SLN counts correlated strongly with the presence or absence of metastasis, with metastasis-positive lymph nodes showing significantly lower counts than negative nodes (p < 0.001). Prediction of SLN metastasis achieved a 100% positive predictive value at a reference value of 10.0, and a 100% negative predictive value at a reference value of 53.0. At a reference value of 19.4, the sensitivity, specificity, and diagnostic accuracy were 77.8, 73.2, and 74.0%, respectively. CONCLUSIONS: The SLN counts detected with lymphoscintigraphy were significantly lower in metastasis-positive lymph nodes than in metastasis-negative lymph nodes. This suggests that prediction of SLN metastasis in breast cancer is possible using lymphoscintigraphy.

Predictive value of bone marrow accumulation of Tc-99m tetrofosmin for subsequent development of distant metastases in breast cancer.

OBJECTIVE: We evaluated the predictive value of bone marrow accumulation of technetium (Tc)-99m tetrofosmin in patients with breast cancer for distant metastases in comparison with conventional prognostic factors such as clinical stage, tumor size, axillary lymph node (Node) status, and estrogen receptor (ER) status. METHODS: Bone marrow scans with Tc-99m tetrofosmin were performed on 64 patients with breast cancer who had no clinical evidence of distant metastases. Accumulation in the femoral marrow was classified into four patterns, no detectable, lower, higher, and intensively higher. Higher or intensively higher pattern was interpreted as abnormal. Thirty-six patients with abnormal accumulation (marrow-positive group) and 28 patients without abnormal accumulation (marrow-negative group) were enrolled in the follow-up study. The mean length of observation after scans was approximately 3 years. The predictive value of femoral marrow status and conventional prognostic factors for distant metastases was evaluated by statistical analysis. RESULTS: Univariate analysis showed a significantly higher incidence of subsequent bone metastases (36%>4%; P<0.005), and distant metastases (69%>18%; P<0.001) in the marrow-positive group when compared with the marrow-negative group. Conventional prognostic factors except tumor size were also significantly associated with the development of distant metastases; 77% in clinical stage 3>39% in clinical stages 1, 2, P<0.05; 64% in Node-positive>29% in Node-negative, P<0.01; and 70% in ER negative>27% in ER positive, P<0.005. These conventional factors were not significantly associated with bone metastases. The Cox proportional hazard ratio for bone metastases was markedly higher in femoral marrow status (hazard ratio=11.07). The distant metastases-free survival was significantly reduced in ER negative (P<0.0005), Node-positive (P=0.0215), and clinical stage 3 patients (P=0.0163). On the other hand, a more marked difference was observed in the femoral marrow status (P<0.0001). The hazard ratio for distant metastases was 2.44 in clinical stage, 2.74 in tumor size, 2.74 in Node, and 3.68 in ER, which were each independent prognostic factors associated with distant metastases. However, femoral marrow status was markedly associated with distant metastases (hazard ratio=5.27). CONCLUSIONS: Bone marrow accumulation of Tc-99m tetrofosmin can be a promising prognostic factor independent of conventional prognostic factors for predicting development of not only bone metastases but also distant metastases in breast cancer.

A case of malignant pheochromocytoma with early intense uptake and immediate rapid washout of 99mTc-tetrofosmin characterizing the overexpression of anti-apoptotic Bcl-2.

Defective apoptotic program due to the overexpression of the anti-apoptotic Bcl-2 protein of the outer mitochondrial membrane may be a cause of the poor response of malignant pheochromocytoma to 131I-MIBG therapy. We report a case of malignant pheochromocytoma which showed early intense uptake and immediate rapid washout of 99mTc-tetrofosmin characterizing the overexpression of anti-apoptotic Bcl-2 and which was refractory to 131I-MIBG therapy.

Usefulness of a solid-state gamma camera for sentinel node identification in patients with breast cancer.

BACKGROUND: A solid-state gamma camera was recently developed. This tool may enable intra-operative imaging of sentinel nodes in breast cancer. The aim of the present study was to evaluate the usefulness of a solid-state gamma camera for the pre- and intra-operative identification of sentinel nodes in patients with breast cancer. METHODS: Breast cancer patients with clinically negative nodes underwent sentinel node biopsy using dye and radioisotopes. Lymphoscintigraphy using both the conventional Anger camera and the solid-state gamma camera was performed the day before surgery. Sentinel nodes were intra-operatively identified using the gamma probe and imaged with a solid-state gamma camera, and then excised. When several sentinel nodes were present, these steps were repeated. RESULTS: Twenty-nine patients (30 basins) were enrolled in the study. The mean patient age was 54 years and the mean tumor size was 16 mm. A total of 41 sentinel nodes were identified using the Anger camera or the solid-state gamma camera pre-operatively. Thirty-eight sentinel nodes (92.7%) were identified using both the Anger camera and the solid-state gamma camera, 1 sentinel node (2.4%) was identified using the Anger camera alone, and 2 sentinel nodes (4.9%) were identified using the solid-state gamma camera alone. A total of 63 sentinel nodes were identified using the gamma probe or the solid-state gamma camera intra-operatively, and were excised. Fifty-seven sentinel nodes (90.5%) were identified using both the gamma probe and the solid-state gamma camera, 3 sentinel nodes (4.8%) were identified using the gamma probe alone, and 3 sentinel nodes (4.8%) were identified using the solid-state gamma camera alone. CONCLUSIONS: The solid-state gamma camera is useful for pre- and intra-operative identification of sentinel nodes in breast cancer. The significance of the solid-state gamma camera could be that it compensates for the gamma probe when the gamma probe cannot identify some sentinel nodes because of the shine through effect, and avoids leaving the residual sentinel nodes behind the axilla intra-operatively.

Potential of (99m)Tc-MIBI for detecting bone marrow metastases.

UNLABELLED: In this study, we evaluated the potential of (99m)Tc-hexakis-2-methoxyisobutylisonitrile (MIBI) for detecting bone metastases in comparison with a conventional bone tracer. METHODS: (99m)Tc-MIBI and (99m)Tc-hydroxymethylene diphosphonate (HMDP) scans were obtained from 99 patients with proven malignant diseases and suspected bone metastases. We compared 373 lesions that showed abnormal uptake on (99m)Tc-MIBI scans or (99m)Tc-HMDP scans (or both). RESULTS: Bone metastases were confirmed in 334 of 373 lesions. Thirty-nine lesions on (99m)Tc-HMDP scans had false-positive findings, but only 2 of these lesions had false-positive findings on (99m)Tc-MIBI scans. (99m)Tc-MIBI and (99m)Tc-HMDP scans were equivalent in 168 of 334 lesions (50.3%). (99m)Tc-MIBI scans correctly detected more lesions than (99m)Tc-HMDP scans: 284 lesions (85.0%) versus 218 lesions (65.3%) (P < 0.005), respectively. (99m)Tc-MIBI scans showed a markedly higher sensitivity for detecting metastases in the femur and humerus compared with (99m)Tc-HMDP scans: 97 of 98 lesions (99.0%) versus 35 of 98 lesions (35.7%) (P < 0.005) and 21 of 22 lesions (95.5%) versus 11 of 22 lesions (50.0%) (P < 0.005), respectively. (99m)Tc-HMDP scans of 17 patients showed no abnormal images. However, (99m)Tc-MIBI scans correctly detected bone metastases, and subsequent development of multiple lesions was observed on follow-up (99m)Tc-HMDP scans of 15 patients. (99m)Tc-MIBI scans were superior to (99m)Tc-HMDP scans in the detection of metastases attributed to breast cancer, multiple myeloma, and hepatoma. On the contrary, (99m)Tc-MIBI scans were less sensitive than (99m)Tc-HMDP scans for detecting bone metastases attributed to prostate cancer in the other skeletal sites except for femur and humerus. CONCLUSION: (99m)Tc-MIBI scans have better sensitivity for detecting bone metastases and provide more specific complementary findings than conventional bone scans. (99m)Tc-MIBI accumulation attributed to bone marrow metastases may occur at an early stage, before the bone remodeling process in the surrounding bone can be detected on conventional bone scans.