Harmonic subtraction for evaluating right ventricle ejection fraction from planar equilibrium radionuclide angiography.

We report an initial investigation of a subtraction-based method to estimate right ventricle ejection fraction (RVEF) from ECG-gated planar equilibrium radionuclide angiography (ERNA) data. Twenty-six consecutive patients referred for scintigraphic evaluation of cardiac function prior to chemotherapy had ECG-gated first-pass (FP) imaging and ERNA imaging performed following the same radiotracer injection. RVEF was computed from FP images (RVEFFP) and separately from ERNA images (RVEFERNA). Standard methods for computing ejection fractions were used to obtain RVEFFP values. RVEFERNA values were obtained using harmonic subtraction of the left ventricular contribution from a biventricular region of interest contoured on the equilibrium images acquired in the shallow right anterior oblique projection. Clinically acquired chest CT data were used to derive information regarding the relative position of the left and right ventricle and about the presence of pulmonary artery enlargement. Computation of RVEFERNA was successful for each of the 26 patients. Computation of RVEFFP failed for four patients. For the 22 patients for which RVEF was computed using both methods, the average RVEFFP was 49% and the average RVEFERNA was 51%, with coefficients of variation of 11 and 7.5%, respectively. Low RVEFERNA values were associated with pulmonary artery dilation. Estimation of RVEFERNA, using a harmonic subtraction-based method of computation is clinically feasible and accurate in the patient population studied. The results support further investigation in patients with frank heart failure.

The EANM and SNMMI practice guideline for lymphoscintigraphy and sentinel node localization in breast cancer.

PURPOSE: The accurate harvesting of a sentinel node in breast cancer includes a sequence of procedures with components from different medical specialities, including nuclear medicine, radiology, surgical oncology and pathology. The aim of this document is to provide general information about sentinel lymph node detection in breast cancer patients. METHODS: The Society of Nuclear Medicine and Molecular Imaging (SNMMI) and the European Association of Nuclear Medicine (EANM) have written and approved these guidelines to promote the use of nuclear medicine procedures with high quality. The final result has been discussed by distinguished experts from the EANM Oncology Committee, the SNMMI and the European Society of Surgical Oncology (ESSO). CONCLUSION: The present guidelines for nuclear medicine practitioners offer assistance in optimizing the diagnostic information from the SLN procedure. These guidelines describe protocols currently used routinely, but do not include all existing procedures. They should therefore not be taken as exclusive of other nuclear medicine modalities that can be used to obtain comparable results. It is important to remember that the resources and facilities available for patient care may vary.

Status of sentinel lymph node for breast cancer.

Long-awaited results from randomized clinical trials designed to test the validity of sentinel lymph node biopsy (SLNB) as replacement of axillary lymph node dissection (ALND) in management of early breast cancer have recently been published. All the trials conclude SLNB has survival rates comparable to those of ALND (up to 10 years in one study) and conclude SLNB has less morbidity than ALND. All the trials support replacing ALND with SLNB for staging in early breast cancer; all support SLNB as the standard of care for such cancer. The SLNB protocols used in the trials varied, and no consensus that would suggest a standard protocol exists. The results of the trials and of other peer-reviewed research do, however, suggest a framework for including some specific methodologies in accepted practice. This article highlights the overall survival and disease-free survival data as reported from the clinical trials. This article also reviews the status of SLN procedures and the following: male breast cancer, the roles of various imaging modalities (single-photon emission computed tomography/computed tomography, positron emission tomography/computed tomography, and ultrasound), ductal carcinoma in situ, extra-axillary SLNs, SLNB after neoadjuvant chemotherapy, radiation exposure to patients and medical personnel, and a new radiotracer that is the first to label SLNs not by particle trapping but by specific macrophage receptor binding. The proper Current Procedural Terminology (CPT) code for lymphoscintigraphy and SLN localization prior to surgery is 78195.

Intraoperative gamma imaging of axillary sentinel lymph nodes in breast cancer patients.

Sentinel lymph node (SLN) biopsy is now standard practice in the management of many breast cancer patients. Localization protocols vary in complexity and rates of success. The least complex involve only intraoperative gamma counting of radiotracer uptake or intraoperative visualization of blue-dye uptake; the most complex involve preoperative gamma imaging, intraoperative counting and intraoperative dye visualization. Intraoperative gamma imaging may improve some protocols. This study was conducted to obtain preliminary experience and information regarding intraoperative imaging. Sixteen patients were enrolled: 8 in a protocol that included intraoperative counting and dye visualization (probe/dye), 8 in a protocol that involved intraoperative imaging, counting and dye visualization (camera/probe/dye). Preoperative imaging of all 16 patients was performed using a GE 500 gamma camera with a LEAP collimator (300 cpm/muCi). The results of this imaging were not, however, given to the surgeon until the surgeon had completed the procedures required for the study. A Care Wise C-Trak probe was used for intraoperative counting. A Gamma Medica Inc. GammaCAM/OR (12.5 x 12.5 cm FOV) with a LEHR collimator (135 cpm/muCi) was used for intraoperative imaging. Times from start of surgery to external detection of a radioactive focus and to completion of excision of SLNs were recorded. Foci were detected preoperatively via imaging in 16/16 patients. Intraoperative external detection using the probe was accomplished in less than 4 min (mean = 1.5 min) in 15/16 patients, and via intraoperative imaging in 6/8 patients. The average time for completion of excision of nodes was 19 min for probe/dye and 28 min for camera/probe/dye. In one probe/dye case, review of the preoperative images prompted the surgeon to resume axillary dissection and remove one additional SLN.

Immunohistochemical evaluation of sentinel lymph nodes in breast carcinoma patients.

Sentinel lymph node sampling has become an alternative to axillary lymph node dissection to provide prognostic and treatment information in breast cancer patients. The role of immunohistochemistry has yet to be established. A total of 241 sentinel lymph nodes (in 270 slides) from 91 patients with invasive carcinoma (73 ductal, 9 lobular, 8 mixed lobular/ductal, 1 NOS) were studied for presence of macrometastases (> 0.2 cm), identified in hematoxylin and eosin sections, and occult metastases (micrometastases [< or = 0.2 cm], clusters of cells, isolated carcinoma cells), identified only by immunohistochemistry. Intraoperative touch preparations, frozen sections, seven hematoxylin and eosin levels (L1-L7), and two AE1-3 cytokeratin immunohistochemistries (L1, L4-5) of the entire bisected or trisected sentinel lymph node were examined. Thirty-one (34%) patients had 50 positive sentinel lymph nodes. Twenty-six (33%) sentinel lymph nodes had metastatic carcinoma (11 macrometastases, 11 micrometastases, 3 clusters of cells, 1 isolated carcinoma cells) by touch preparations, frozen sections, and one hematoxylin and eosin (L1). Thirty-eight (43%) were positive by AE1-3 immunohistochemistry (L1) (11 macrometastases, 8 micrometastases, 13 clusters of cells, 6 isolated carcinoma cells), significantly more than by touch preparations, frozen sections, hematoxylin and eosin L1, or hematoxylin and eosin L2-7. Cytokeratin immunostain on L4-5 demonstrated 31 (34%) positive sentinel lymph nodes, a similar frequency to cytokeratin immunostain on L1. Size of sentinel lymph node metastasis did not correlate with size, histologic grade, or type of primary breast carcinoma. AE1-3 (L1) immunohistochemistry is highly sensitive in delineating sentinel lymph node metastasis, especially clusters of cells and isolated carcinoma cells. The prognostic significance of clusters of cells and isolated carcinoma cells and the value of AE1-3 immunohistochemistry on frozen sections need to be determined.