Usefulness of scintimammography with tc-99m MIBI in clinical practice.

Radiographic mammography (MM) is routinely used to diagnose breast cancer. MM has a number of well-known limitations, especially in cases of a dense or dysplastic breast. Scintimammography (SM) with Tc-99m MIBI has been successfully used as a useful complement to MM. The authors report a case of a 57-year-old woman with MM with tiny calcifications in the left breast, which were classified by the radiologist as probably benign lesions. SM with Tc-99m MIBI showed a focal area of increased uptake in the upper outer quadrant of the left breast. On the basis of SM results, an excisional biopsy was performed and pathologic examination revealed infiltrating ductal carcinoma.

Slow coronary flow and stress myocardial perfusion imaging. Different patterns in acute patients.

OBJECTIVE: We investigated myocardial perfusion in acute patients with slow coronary flow (SCF) at angiography. Whether impaired myocardial perfusion occurs in acute patients with SCF is unknown. METHODS: We enrolled 28 consecutive patients with SCF in the epicardial coronary arteries with no evidence of significant stenosis. SCF affected a single coronary artery in 14 patients (group A) and all three coronary vessels in 14 others (group B). Coronary angiography was repeated after dipyridamole infusion and single photon emission computed tomography was performed using dipyridamole as the stress agent. The Thrombolysis in Myocardial Infarction frame count was measured in SCF vessels at baseline and after dipyridamole infusion. RESULTS: Mean Thrombolysis in Myocardial Infarction frame count significantly decreased after dipyridamole in both groups. At baseline, mean values of the single photon emission computed tomography score were 31.5 +/- 1.6 and 25.1 +/- 2.1 in groups A and B, respectively. After dipyridamole, they increased from 31.5 +/- 1.6 to 37.8 +/- 1.4 (P < 0.001) in group A, whereas a further decrease to 15.0 +/- 1.2 (P < 0.005) was observed in group B. CONCLUSIONS: An opposite behavior of myocardial perfusion was observed after dipyridamole infusion: a normal response in patients with SCF affecting one single coronary artery versus an ischemic-like response in those with CSF affecting all three coronary arteries.

High resolution scintimammography helps in differentiating benign from malignant findings in scintigraphic hot spots.

Several efforts have been focusing on the development of detectors devoted to high solution (99m)Tc sestamibi scintimammography to improve sensitivity for non palpable lesions. To this aim new high resolution scintillation gamma camera was developed under the "Integiated Mammographic Imaging" project. The gamma camera, made by CAEN and Pol.Hi.Tech, has an overall dimension of 112x120x75mm3. It consists of an array of 1 in. PSPMTs Hamamatsu H8520-C12 closely packed, a NaI(T1) scintillation array (1.8x1.8x6mm(3) pixel) and a general purpose collimator. By this gamma camera a clinical experience on a few patients with breast cancer suspicion was performed. In this paper we show how high resolution approach allows to better categorize the lesions on the basis of the morphology of the spatial distribution of the radiotracer in the breast tissue. By comparing conventional and high resolution images of a young patient (29 y.o.) with breast cancer suspicion, it appears clear how the Anger, camera images showed a defined hot spot, highly suggestive of malignant lesion; on the contrary, the high resolution scan shown a large and inhomogeneous uptake area with the absence of clear and focal character of the uptake, to be considered as a probably non malignant lesions. This resuh was confirmed by byoptical findings that diagnosed the echographic findings as a benign inflammatory lesion.

Detection of colon cancer with 99mTc-labeled bombesin derivative (99mTc-leu13-BN1).

Breast, prostate, and lung cancer have been successfully detected with 99mTc bombesin (99mTc-leu13-BN1), the radiopharmaceutical that our group developed from synthesis to diagnostic trials. Overexpression of bombesin receptors (BNRs) in colon cancer is well known: the aim of this study was to assess whether or not colon cancer can be detected with a 99mTc-leu13-BN1 scan. Thirteen (13) patients, 7 of whom with known rectal cancer and 6 scheduled to undergo endoscopic removal of polyps for suspicion of colon cancer, were studied with a 99mTc-leu13-BN1 scan. Dynamic, single photon emission computed tomography, and whole-body scans were performed within 1 hour, before discharge of radioactivity from the liver into the duodenum. Sixteen (16) of 17 colorectal cancer locations were detected with a 99mTc-leu13-BN1 scan with 94.1% sensitivity. Six (6) lesions were benign: 1 Crohn's disease, 1 polyp with mild dysplasia, 4 polyps with simple hyperplasia; 99mTc-leu13-BN1 scans were positive in two nontumoral lesions, Crohn's disease, and mild dysplasia and true negative in 4: specificity was 67%. Of the 7 patients with known rectal cancer, 5, who underwent operations instead of radiation therapy, showed lymph-node invasion on 99mTc-leu13-BN1 scans. Operations confirmed the scintigraphic staging. 99mTc-leu13-BN1 is taken up by colon cancer. Scans are sensitive, although scarcely specific. 99mTc-leu13-BN1 allows for node-invasion detection.

Role of 99mTc-bombesin scan in diagnosis and staging of prostate cancer.

Aim of this work was to asses whether a novel 99mTc labeled Bombesin (BN) can play a clinical role in diagnosis and staging of prostate cancer. 14 patients were studied with trans-rectal ultrasonography-guided biopsy, CT and MRI and with 99mTc BN Scintigraphy. Five patients were also imaged by 111In Octreotide (O) scan. All the patients but one were submitted to surgery and final diagnosis was reached by pathology, taken as the gold standard method. Two patients showed benign adenoma and 12 patients showed cancer at biopsy. 99mTc BN SPECT was positive in all 12 patients with cancer. Four of these patients also showed pelvic focal uptake, referred to inguinal lymph-nodal involvement. MRI and CT provided similar findings in only three cases. Pathologic evaluation after operation confirmed the invasion of nodes in all four subjects. Both 99mTc BN and 111In O scans provided normal findings in the two subjects affected by benign adenoma, while 111In O was positive in only two of three patients with cancer and was always unable to detect nodal invasion. These preliminary data suggest that 99mTc BN SPECT scan could be useful to detect primary prostate cancer and to reveal loco-regional node involvement.

99mTc-bombesin detects prostate cancer and invasion of pelvic lymph nodes.

Biopsy is the standard method for the diagnosis of prostate cancer; however, it is inadequate for the assessment of lymph node invasion. Radionuclide imaging might be useful for both diagnosis and N staging, but it requires high uptake of radiotracers in order to overcome difficulties arising from the anatomy of the region. The aim of this study was to assess whether or not technetium-99m labelled bombesin (99mTc-BN) scan is able to detect prostate cancer and invasion of pelvic lymph nodes. Ten patients were studied with 99mTc-BN, transrectal ultrasonography, biopsy, computed tomography and magnetic resonance imaging. All the patients with cancer were operated on. Planar dynamic scintigraphy and single-photon emission tomography (SPET) were performed after administration of 185 MBq 99mTc-BN. Two patients showed benign adenoma and eight showed cancer at biopsy. The average Gleason's score was 7.5+/-1.3. 99mTc-BN dynamic planar scan showed hot spots in the prostatic fossa in two of the eight patients with cancer, both of whom had a prostate-specific antigen level higher than 20 ng/ml. In these patients, high uptake inside the prostatic fossa was detected as early as 1 min after injection, before the arrival of radioactivity in the bladder. True positive SPET scans were obtained in all eight patients with cancer. Invasion of the obturator nodes was detected by SPET in three patients, and in all three was confirmed at surgery. Our preliminary data encourage further studies on the prostate with 99mTc-BN. If the high sensitivity of 99mTc-BN SPET is confirmed, this method may play an important role in diagnosing and staging prostate cancer.