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Biomedical subjects

G Bisi

Publications and source records attributed to G Bisi.

At least 109 records · Page 6Linked to original sources
PubMed1979

[Sequential scintiscanning with 99mTc-HIDA in the study of some aspects of post-operative dynamics of the proximal digestive tract].

The authors exploited the elective biliary excretion of 99mTc-HIDA at adequate concentrations to afford visibility of intestinal segments more directly wetted by bile in a study of sequential hepatobiliary scintigraphy designed to explore the parts of the duodenum and jejunum that are excluded to the transit of gastrointestinal contents in many surgical procedures involving the proximal digestive tract. They illustrate their case material with several representative examples; these are described in detail to show the validity, usefulness and versatility of the scintigraphic technic under discussion.

Adult↗
PubMedDate not supplied

Influence of the assessment of defect severity and intravenous nitrate administration during tracer injection on the detection of viable hibernating myocardium with data-based quantitative technetium 99m-labeled sestamibi single-photon emission computed tomography.

BACKGROUND: This study aimed to verify whether the assessment of defect severity and the infusion of nitrates during tracer injection improve the capability of data-based 99mTc-labeled sestamibi single-photon emission computed tomography (SPECT) to recognize hibernating myocardium. METHODS AND RESULTS: Of 66 asynergic coronary territories in 40 patients with left ventricular dysfunction, 28 had postrevascularization functional recovery (hibernating) and 38 had unchanged dysfunction (fibrotic). Defect severity was lower in the hibernating than in the fibrotic territories on both baseline (p < 0.01) and nitrate SPECT (p < 0.002). Nitrate was superior to baseline SPECT to differentiate the hibernating from the fibrotic territories (sensitivity 96% vs 75%, p < 0.05; receiver-operating characteristic curve area 0.75 vs 0.63, p < 0.001) and to identify the patients with improved left ventricular ejection fraction (receiver-operating characteristic curve area 0.68 vs 0.58; p < 0.05). CONCLUSIONS: The analysis of defect severity in combination with nitrate infusion clearly improves the value of 99mTc-labeled sestamibi SPECT for the recognition of hibernating myocardium and the prediction of postrevascularization recovery.

Adult↗
PubMedDate not supplied

Head-to-head comparison of exercise stress testing, pharmacologic stress echocardiography, and perfusion tomography as first-line examination for chest pain in patients without history of coronary artery disease.

BACKGROUND: To overcome the relatively low accuracy of exercise stress testing (EST) in detecting coronary artery disease (CAD), both echocardiography and perfusion scintigraphy have been evaluated in conjunction with pharmacologic stress, but there is still uncertainty of the relative value of these tests as possible first-line examinations for suspected CAD. This study evaluated the accuracy of EST, dipyridamole and dobutamine stress echocardiography (DIP-ECHO, DOB-ECHO), and dipyridamole and dobutamine technetium 99m sestamibi tomography (DIP-MIBI, DOB-MIBI) for the detection of CAD in patients evaluated for the first time because of chest pain. METHODS AND RESULTS: Sixty patients underwent EST, DIP-ECHO, DOB-ECHO, DIP-MIBI, and DOB-MIBI. Echocardiographic images were acquired simultaneously with sestamibi injections, and the scintigraphic images were collected 1 hour later. Coronary angiography was performed within 15 days. Out of 33 patients with significant (>70%) coronary stenoses, 19 (58%) were correctly identified by EST, 18 (55%) by DIP-ECHO, 20 (61%) by DOB-ECHO, 32 (97%) by DIP-MIBI, and 30 (91%) by DOB-MIBI (p < 0.005 for MIBI vs EST and ECHO). The specificity of EST was 67% (p < 0.05 vs ECHO and MIBI), 96%, 96%, 89%, and 81%, respectively. Of the 62 stenotic coronary arteries, 20 (32%) were correctly identified by DIP-ECHO, 24 (39%) by DOB-ECHO, 48 (77%) by DIP-MIBI, and 45 (73%) by DOB-MIBI. The sensitivity of the imaging techniques in predicting the presence of multivessel disease was 14% and 29% for DIP and DOB-ECHO compared with 48% and 57% for DIP and DOB-MIBI. CONCLUSIONS: Our results confirm the limited reliability of EST in detecting CAD and the good diagnostic value of DIP and DOB-MIBI. Conversely, the lower sensitivity and the poorer capability to recognize multivessel CAD do not support the role of either DIP or DOB-ECHO as first-line examination for suspected CAD.

Chest Pain↗
PubMedDate not supplied

Sentinel lymph node and breast cancer staging: final results of the Turin Multicenter Study.

AIM OF THE STUDY: Validation of the sentinel node (SN) technique in breast cancer by means of lymphoscintigraphy. MATERIALS AND METHODS: From December 1996 to January 1999 102 T1-T2 breast carcinoma cases were recruited in Turin. 99mTc-human serum albumin colloids were injected subdermally the day before surgery (mean activity, 5.2 +/- 2.5 MBq). Scintigraphic imaging was performed after injection. After identification of the SN during surgery by a hand-held gamma probe, the SN was excised and sent for histologic examination. SN histology was compared with that of other axillary nodes. RESULTS: The SN detection rate was 86.3%; among 88 cases with an identified SN, 37 (42%) had axillary metastases; the SN was metastatic in 35 cases (sensitivity, 94.6%); in 51.3% of pN+ cases (19/37) the SN was the only metastatic site. In two of the 53 negative SNs, SN histology did not match with that of the remaining axilla (negative predictive value, 96.2%; staging accuracy, 97.7%). CONCLUSIONS: Our results agree with those reported in the literature; however, except in clinical trials and experienced structures axillary lymph node dissection should not be abandoned when mandatory for prognostic purposes, considering that at present SN biopsy alone is not completely accurate for axillary staging, especially in the absence of an adequate learning period.

Adult↗
PubMedDate not supplied

Radiolabeled localization of the sentinel lymph node: dosimetric evaluation in personnel involved in the procedure.

AIMS AND BACKGROUND: Peritumoral injection of 99mTc-labeled colloids for lymphoscintigraphy and radioguided surgery does not entail any relevant radiation burden to the patients. The real issue about radiation protection concerns the personnel involved in the procedure besides the nuclear medicine personnel. The aim of our study was to evaluate the cumulative doses to personnel involved during the injection of radiolabeled compounds, under ultrasound or stereotactic guidance and the radiation burden to the personnel involved in the surgical incision of the tumor 24 hours after the administration of 99mTc-labeled colloids. METHODS AND STUDY DESIGN: We performed environmental contamination tests (SMEAR TEST) and exposure evaluation in the operating room. RESULTS: In the operating room the removed activity in the analyzed samples was less than 0.5 Bq/g and exposure to the personnel was less than 6 micro Sv/h. The evaluations made during ultrasound guidance demonstrated an equivalent and effective dose less than 20 microSv. CONCLUSIONS: Our results show that during ultrasound or stereotactic administration of radiolabeled compounds the radiation burden to the personnel involved in the procedure is virtually negligible. The surgeons too are exposed to a negligible radiation dose.

Adult↗
PubMedDate not supplied

Preliminary study of sentinel node identification with 99mTc colloid and blue dye in patients with endometrial cancer.

AIMS AND BACKGROUND: Intraoperative lymphatic mapping and sentinel node (SLN) biopsy have generated a tremendous amount of interest and are already established as part of the standard practice in the surgical management of breast cancer and melanoma. To reduce extensive radical procedures and decrease the morbidity in the treatment of gynecologic malignancies, much effort is being made to use less aggressive interventions. The purpose of our study was to determine the feasibility of SLN mapping in a group of patients with endometrial cancer at early stages. METHOD AND STUDY DESIGN: Between September 2000 and May 2001 11 patients with endometrial cancer FIGO stage Ib (n = 10) and IIa (n = 1) underwent laparoscopic SNL detection during laparoscopy-assisted vaginal hysterectomy with bilateral salpingo-oophorectomy and bilateral systematic pelvic lymphadenectomy. Radioactive isotope injection was performed 24 hours before surgery and blue dye injection was performed just before surgery in the cervix at 3,6, 9 and 12 hours. A 350 mm laparoscopic gamma scintyprobe MR 100 type 11, 99mTc settled (Pol Hi Tech), was used intraoperatively for SLN detection. RESULTS: Seventeen (17) SLNs were detected with lymphoscintigraphy (six bilateral and five unilateral). At laparoscopic surgery we found the same locations belonging at internal iliac lymph nodes (the so-called Lebeuf-Godard area, lateral to the inferior vesical artery, ventral to the origin of the uterine artery and medial or caudal to the external iliac vein). Fourteen (14) SLNs were negative on histological analysis and three were positive for micrometastases (mean SLN sections = 60). All other pelvic lymph nodes were negative at histological analysis. The same SLN locations detected with the gamma scintyprobe were observed at laparoscopy after patent blue dye injection. CONCLUSIONS: Our preliminary data suggest that combined 99mTc-labeled colloid and vital blue-dye techniques are feasible for SLA detection in endometrial cancer; they represent a very promising tool to transform the management of early-stage endometrial cancer. The clinical validity of this combined technique should be evaluated prospectively.

Adult↗
PubMedDate not supplied

Sentinel node detection in breast carcinoma.

AIMS AND BACKGROUND: The standard procedure for the evaluation of axillary nodal involvement in patients with breast cancer is still complete lymph node dissection. However, about 70% of patients are found to be free of metastatic disease while axillary node dissection may cause significant morbidity. Lymphatic mapping and sentinel lymph node (SLN) biopsy are changing this situation. METHODS AND STUDY DESIGN: In a period of 18 months we studied 201 patients with breast cancer, excluding patients with palpable axillary nodes, tumors > 2.5 cm in diameter, multifocal or multicentric cancer, pregnant patients and patients over 80 years of age. Before surgery 99mTc-labeled colloid and vital blue dye were injected into the breast to identify the SLN. In lymph nodes dissected during surgery the metastatic status was examined by sections at reduced intervals. Only patients with SLNs that were histologically positive for metastases underwent axillary dissection. RESULTS: We localized one or more SLNs in 194 of 201 (96.5%) patients; when both techniques were utilized the success rate was 100%. Histologically, 21% of patient showed SLN metastases (7.8% micrometastases) and 68% of these had metastases also in other axillary nodes. None of the patients with negative SLNs developed metastases during follow-up. CONCLUSIONS: At present there is no definite evidence that negative SLN biopsy is invariably correlated with negative axillary status; however, our study and those of others demonstrate that SLN biopsy is an accurate method of axillary staging.

Aged↗
PubMedDate not supplied

[Lymphoscintigraphic localization of sentinel lymph nodes in colorectal carcinoma in early stage: results of a single center study and proposal of a multicenter protocol].

In colorectal cancer the sentinel node dissection may help to identify any unusual mesenteric lymphatic drainage pattern from the primary tumor site (ex/skip metastases); assuming that accurate pathological staging is critical for therapeutic decisions we are conducing a study to evaluate the feasibility of the sentinel node technique in colorectal neoplasms and its overall accuracy in predicting regional lymph nodes metastases for appropriate staging. From February 2001 to September 2004 we included in this study 30 patients with rectal lesions or degenerate colonic polyps not radically excised by endoscopy. Lymphatic mapping was performed with low molecular weight albumin colloid labelled with 500Mci of 99mTc in a 2 ml volume and injected submucosally by an endoscopic route at the four cardinal points around the tumor, the afternoon before the surgical procedure, both in case of colonic or rectal lesions. Scintigraphic images were obtained with a gamma camera fitted with a general purpose collimator. The day of the intervention, a hand held gamma detecting probe (Scintiprobe m100, Pol-Hi-Tech, Italy) was employed to detect the "hot" nodes, in vivo and ex vivo. These lymph nodes were tagged with a stitch in vivo; the specimen was removed by a standard resection and SLN were dissected ex vivo and sent separately for pathological examination. In case of rectal lesions, the sentinel nodes were searched ex vivo into mesorectal fat in case. All lymph nodes, including blue or hot ones, were embedded separately for preparation of paraffin sections and haematoxylin and eosin staining. Sentinel lymph node were submitted to multi-seriate sections in order to look for micrometastases. Using the radioactive tracer, sentinel lymph nodes were successfully identified in 27 out of 30 patients. Concordance between SLNs and nodal status was observed in 23 out of 27 cases (85%); two patients (7.4%) were upstaged, as SLN was the only site of metastases. In another two cases we observed no concordance between negative sentinel node and non sentinel nodes (false negative rate, 7.4%). Starting from this experience we are proposing a multicentric trial concerning the value of sentinel node technique in rectal cancer and in early colorectal cancers detected by screening programs.

Clinical Protocols↗
PubMedDate not supplied

Repeated 99mTc-Sestamibi studies for the evaluation of salvaged myocardium and of its relationship with postinfarction ischemia.

Pre- and post-treatment myocardial scans with 99mTc-Sestamibi demonstrated effective reperfusion after thrombolysis in a patient with acute myocardial infarction. Late follow-up images showed at rest a further noteworthy reduction of the uptake defect and that during exercise a large part of the salvaged territory became ischemic. This report demonstrates that a remarkable amount of myocardium in the posttreatment images was hibernated; furthermore, it was possible to visualize directly that the salvaged territory is the actual site of exercise induced postinfarction ischemia.

Heart↗