Etsuji Nomura

Radioguided sentinel node detection in breast cancer patients: comparison of 99mTc phytate and 99mTc rhenium colloid efficacy.

BackgroundRadioguided sentinel node biopsy (SNB) of breast cancer patients has become a standard method for detecting early stage breast cancer. However, no standard radiopharmaceutical exists. Methods99mTc rhenium colloid or 99mTc phytate SNB was used to aid detection in breast cancer patients. For each radiopharmaceutical, 100 patients were examined. The following points were compared: (1) scintigraphic detection rate of axillary sentinel nodes (detectability and number when detectable) and internal mammary sentinel nodes; (2) the number of nodes detected scintigraphically and the number detected during surgery; (3) sensitivity, specificity, accuracy, negative predictive value, and positive predictive value for axillary sentinel nodes. ResultsAxillary sentinel nodes of patients were biopsied using either 99mTc rhenium or 99mTc phytate. The number of axillary nodes surgically removed from patients given 99mTc rhenium was 2.28±1.08 (mean±SD), and the number of axillary nodes surgically removed from patients given 99mTc phytate was 1.68±0.82. Some patients given 99mTc rhenium showed a spill-over of radioactivity from sentinel nodes. Concordance of scintigraphically detected nodes and surgical removed nodes was superior for 99mTc phytate compared to that with 99mTc rhenium, with a statistically significant difference. The sensitivity and negative predictive value was superior with 99mTc phytate compared to that with 99mTc rhenium, even though no statistical difference was detectable. However, visualization of internal mammary nodes was superior with 99mTc rhenium. ConclusionIn breast cancer patients, 99mTc phytate is a better choice for the detection of axillary SNB than 99mTc rhenium colloid. However, 99mTc rhenium colloid is a better choice for the detection of internal mammary nodes.

Improved detection of axillary hot nodes in lymphoscintigraphy in breast cancer located in the upper lateral quadrant with additional projection imaging.

Background: Sentinel node (SN) biopsy has been becoming a standard method for early stage breast cancer. Scintigraphic image of SN helps the biopsy procedure. It is reported that the scintigraphic detection rate is not 100%. The value of taking additional projection view in SN detection was assessed in breast cancer patients.Patients and Methods: Consecutive 114 breast cancer patients with upper lateral quadrant tumor were included in this study. After injection of99mTc-phytate, scintigram was taken at the projection of anterior oblique (AO) 30° view and an additional AO 60° view. Images were evaluated visually.Results: In 7 of 114 patients, an axillary hot node was hidden on the activity at the injected site on AO 30° view, and was visualized on AO 60° view. In 17 of 114 patients, the axillary hot node was seen as a hump from the injected activity, and was separate on AO 60° view. In 90 of 114 patients, the axillary hot node was separately seen on AO 30° view.Conclusion: Multi-directional views are helpful to depict the axillary sentinel nodes that are concealed behind the injected radioactivity.

An easy and reproducible semi-automatic method for the evaluation of99mTc-galactosyl human serum albumin

Abstract99mTc-galactosyl human serum albumin (99mTc-GSA) scintigraphy is a new method for evaluating liver function. This scintigraphy is useful for evaluating the severity of liver diseases. The indices evaluating hepatic function include the receptor index (LHL15) and the index of blood clearance (HH15). These indices are calculated on the basis of the regions of interest (ROIs) for both whole liver and heart, and are susceptible to the ROIs over heart and liver. At present, there is no standard method for determining ROIs. We attempted to establish a standard method which shall not be subject to inter and/or intra operator variation. A computer program to determine heart and liver ROIs semi-automatically was developed. Ten patients (12 instances) were studied with99mTc-GSA, and HH15 and LHL15 were calculated on the basis of the ROIs obtained manually and semiautomatically by 3 different operators independently. Blood sampling and gamma-counting yielded blood clearance data. The ICG R15 was compared with each index in 34 patients. The time needed for ROI determination was reduced from 2–3 minutes for the manual method to 0.5–0.8 minutes for the semi-automatic method. The % coefficients of variation (% CVs) of HH15 and LHL15 were improved in the order manual-inter observer (M-inter), manual-intra observer (M-intra) and semiautomated-inter observer (SA-inter); % CVs of HH15 were 2.26% for M-inter, 1.55% for M-intra and 0.07% for SA-inter, and % CVs of LHL15 were 2.29% for M-inter, 0.46% for M-intra and 0.07% for SA-inter. The correlation of HH15 and LHL15 among M-inter, M-intra and SA-inter was good. Comparison of indices obtained by manual and semi-automatic methods with blood clearance data obtained by blood sampling and gamma-counting showed good correlations and no significant differences. The comparison with ICG R15 showed that HH15 and LHL15 by the semi-automated method gave better correlation that that by the manual method. A newly developed semi-automated method improved data processing time and deviation of indices in99mTc-GSA studies. This method should substitute for manual ROI determination.

Scintigraphic detection of recurrence of medullary thyroid cancer

A case of recurrent medullary thyroid cancer (MTC) was evaluated with123I-MIBG,99mTc(V)-dimercaptosuccinic acid (DMSA), and201Tl scintigraphy. This patient had been operated on for MTC in the right thyroid. Recently a left neck mass was noticed, and was suspected of being a. recurrence of MTC based on increased plasma calcitonin (CT) and carcinoembryonic antigen (CEA). He was operated on for the neck mass which revealed MTC, and papillary thyroid cancer was incidentally found in the left thyroid, but the CT and CEA levels remained high, and remaining MTC tumor was suspected. But the location of the tumor was unknown. Although99mTc(V)-DMSA scintigraphy is generally believed to be superior in sensitivity to123I-MIBG scintigraphy, it did not demonstrate the tumor site but201Tl and123I-MIBG did. Furthermore,123I-MEBG scintigraphy has greater specificity for tumors which arise in the neural crest. Judging from the results of this case and cases reported in the literatures, both123I-MIBG and99mTc(V)-DMSA should be performed in the detection of recurrent MTC.