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Biomedical subjects

P De Nardi

Publications and source records attributed to P De Nardi.

17 recordsLinked to original sources
PubMed1998

Preoperative and intraoperative radioimmunodetection of cancer pretargeted by biotinylated monoclonal antibodies.

The in vivo post-targeting of tumor by means of anti-carcinoembryonic-antigen (CEA) monoclonal antibodies (MAbs) and the avidin-biotin three-step system was tested by immunoscintigraphy and radioimmunoguided surgery (RIGS) in six patients with primary or recurrent rectal cancer. The patients were preoperatively injected with 1 mg of FO23C5 (anti-CEA) and/or B72.3 anti-tumor-associated glycoprotein (TAG-72) biotinylated MAb; after 24 hours, 1 mg of avidin was administered, and, after a further 24 hours, biotin labeled to Indium-111 (In111) was injected. Preoperative imaging was obtained by means of a gamma camera, and a portable gamma-detecting probe (Neoprobe 1000) was intraoperatively used to count tumor and surrounding normal tissue. Eight tumor sites were localized in the six patients. Four lesions were identified preoperatively and six intraoperatively with a mean tumor-to-normal-tissue (T/NT) ratio of 1:8. This method allowed preoperative scintigraphy and intraoperative radioimmunodetection to be performed with a single radioactive compound injection of biotin labeled to In111 within few days before surgery.

Adult↗
PubMed1995

A postgraduate teaching course in laparoscopic surgery.

A teaching course in laparoscopic surgery was addressed to 21 young postgraduates as a part of their general surgery program with the aim of making them familiar with the basic principles of laparoscopic surgery. The methodology was based on tutorial teaching and "learning by problems"; the students worked in little groups elaborating check lists, discussing problems, and practising with laparoscopic training devices. Theoretical learning, practical abilities, and efficacy of tutorial teaching were investigated at the end of the course: the participant's understanding of instrument function, mastering of equipment, and solutions to clinical problems were good, as were the efficiency and pleasantness of the didactic method. Tutorial teaching seems to be a valid model for basic training in laparoscopic surgery in a modern medical education program.

Education, Medical, Continuing↗
PubMed1994

Avidin-biotin system in radioimmunoguided surgery for colorectal cancer. Advantages and limits.

PURPOSE: Radiolabeled monoclonal antibodies (MAbs) have been reported to allow tumor intraoperative detection by means of a gamma-detecting probe. The technology is called the Radioimmunoguided Surgery (RIGS) system. The main inconveniences of the method are 1) the long interval needed for clearance of unattached MAbs from the patient's body, between the injection of the MAb and surgery, and 2) the low sensitivity of current MAbs used in detecting small tumors. We describe a new method to overcome these inconveniences using biotinylated MAbs and avidin in order to obtain a rapid blood clearance of the radiolabeled MAbs both anticarcinoembryonic antigen and antitumor-associated glycoprotein-72 MAbs. METHODS: Twenty patients with primary and recurrent colorectal cancer have been enrolled in the study; 125I-biotinylated MAbs FO23C5 (anticarcinoembryonic antigen) and B72.3 (antitumor-associated glycoprotein-72) followed by cold avidin were injected in 13 patients and 7 patients, respectively. RESULTS: A decrease of 94 +/- 3 percent of circulating radioactivity was achieved in 3 to 5 days. Patients underwent surgery approximately seven days after MAb injections rather than after four weeks. Tumors were localized in 14/20 (70 percent) patients (true positive), 2 (10 percent) were false negative, and 4 (20 percent) were true negative. The overall sensitivity level in early-stage primary cancers was 37 percent when related to the presence of disease and 75 percent when related to antigenic expression. The sensitivity for more advanced cancer and for recurrences was 100 percent. Moreover, the in vivo tumor targeting of biotinylated MAb was demonstrated in frozen tumor section by direct streptoavidin-peroxidase staining. CONCLUSIONS: The avidin-biotin system may enhance applicability and effectiveness of radioimmunoguided surgery (RIGS).

Antibodies, Monoclonal↗
PubMed1994

Radioimmunoguided surgery using iodine-125-labeled biotinylated monoclonal antibodies and cold avidin.

UNLABELLED: One of the limitations of intraoperative tumor detection with radiolabeled monoclonal antibody (Mab), by means of a gamma-detecting probe (GDP), is the long time interval needed between Mab injection and surgery to obtain low blood-pool activity. Such an interval can be shortened considerably, exploiting the high affinity between avidin and biotin. METHODS: Twenty patients with colorectal cancer were injected with 1 mg of biotinylated 125I monoclonal antibodies followed, 48 hr later, by a chase of cold avidin. During surgery, the GDP was used to detect radioactive emissions from the tumor and normal tissue. Tumor tissue samples were analyzed in vitro by immunohistochemical tests for the presence of tumor antigens and in vivo antibody localization. RESULTS: At the time of surgery (average 7 days postinjection), the mean value of circulating radioactivity was 6% +/- 3% of the injected dose. Of 20 patients studied, tumors were localized in 13 cases (65%). Subclinical tumors were detected in 3 patients (15%). CONCLUSION: The use of 125I-labeled biotinylated Mabs followed by avidin as a chase enhances the applicability and effectiveness of radioimmunoguided surgery technology and will allow the use of radioisotopes with a shorter half-life than 125I.

Antibodies, Monoclonal↗
PubMed1994

Role of B72.3 iodine 125-labeled monoclonal antibody in colorectal cancer detection by radioimmunoguided surgery.

BACKGROUND: Radioimmunoguided surgery (RIGS) by means of radiolabeled monoclonal antibodies and a probe has been reported to be useful in recognizing subclinical tumor deposits during operation. Aim of this study was to understand the limits of this technique and to assess the potential diagnostic use of RIGS in colorectal cancer surgery. METHODS: Monoclonal antibody B72.3 reacting with TAG 72 antigen, labeled with iodine 125, was injected in 32 patients with primary tumors and in 22 patients with recurrent colorectal cancer. One hundred thirty-three suspected tumor sites were evaluated during operation by means of probe and resected with immunohistochemistry as control. RESULTS: Primary tumor sites were localized by RIGS in 60% of cases, and recurrent sites were localized in 82% of cases. There was a significant correlation both for primary (p < 0.001) and recurrent (p < 0.001) tumor sites between intraoperative RIGS findings and TAG 72 tumor antigen expression. Results obtained with the probe were instrumental in modifying the surgical approach in six (27%) of 22 patients with recurrences, allowing the removal of tumor masses that would otherwise have been overlooked. CONCLUSIONS: The results of RIGS seems to be encouraging in terms of clinical use. The potential high diagnostic resolution appears to improve surgical ablation of colorectal cancer, especially in patients with recurrent cancer or suspected recurrent tumors who have negative results for intraabdominal disease by all other roentgenographic criteria with rising carcinoembryonic antigen or TAG 72 antigen levels.

Adult↗
PubMed1993

An oncocytic carcinoma of the pancreas with pulmonary and subcutaneous metastases.

A 72-year-old man with an oncocytic carcinoma of the pancreas of 3 years' duration was treated by pancreatoduodenectomy; 5 and 16 months later, two pulmonary metastases and one subcutaneous metastasis of the thigh were removed. No sign of local recurrence or metastases was present at 20-month follow-up. It is suggested that oncocytic carcinomas of the pancreas have a favorable prognosis if treated surgically.

Aged↗
PubMed1993

Localization of biotinylated monoclonal antibodies (B72.3 and F023C5) in patients with colorectal cancer.

The recognition and treatment of neoplastic lesions in early phases are among the most important aims of research using monoclonal antibodies (MoAb). Recent studies have demonstrated that the use of radiolabelled MoAb directed against tumor associated antigens and hand-held gamma detecting probe (GDP) could help in the recognition of primary tumors and metastases. The goal of this study was to investigate the in vivo antibody reaction as shown by histologic preparations after injection of 125I biotinylated MoAb (B72.3 or F023C5) before surgery and to compare the immunohistochemical results with those obtained with GDP in colorectal cancer. We studied 15 cases of patients with primary or recurrent colorectal cancer. The biotinylated, radiolabelled antibody administered in vivo could be seen in frozen sections with streptoavidin peroxidase complex. In 14 cases there was agreement between GDP observations and detection of the in vivo injected biotinylated MoAb with direct staining using streptoavidin peroxidase conjugate. The use of MoAbs thus provides a means of correlating the intraoperative signal with the presence of the injected antibodies on the tumor.

Antibodies, Monoclonal↗
PubMed1991

Surgery for colorectal cancer guided by radiodetecting probe. Clinical evaluation using monoclonal antibody B72.3.

Radioactive antibodies that react with tumour-associated antigens to "tag" antigen-positive tumour cell deposits were given to 20 patients with primary or recurrent colorectal cancer. The tumour associated antigen TAG 72-specific monoclonal antibody B72.3 labelled with 125-Iodine was used, and the radioactivity in the tumour was sought during operation with a hand-held gamma detecting probe. Tumour was detected by the probe in 7 of 15 patients with primary cancer, with a mean tumour: normal tissue ratio of 3.9, and in 4 of 5 patients with recurrent disease, with a mean tumour: normal tissue ratio of 2.0. Immunohistochemical analysis of surgical specimens confirmed the results of the intraoperative detection. The incidence of TAG 72-positive tumours (11/20, 55%), detected by immunohistochemistry, was lower than the 80% in the other series, possibly because of sampling errors or because the cases studied were uncomplicated with small primary tumours. Results obtained with the probe were instrumental in modifying the operation in two of the four "positive" patients with recurrences, allowing the removal of tumour masses that would otherwise have been overlooked.

Adenocarcinoma↗
PubMedDate not supplied

A new method for faster blood clearance in radioimmuno-guided surgery.

A major inconvenience of intraoperative tumor detection with radiolabeled monoclonal antibody (MoAb) by means of a probe is the long interval needed between the injection of MoAb and surgery (at least 20 days). We describe a new method which entails injection of 125I-labeled biotinylated monoclonal antibodies and cold avidin in order to obtain a rapid blood clearance of the radiotracer. The first clinical application of this protocol has been carried out in a colon cancer patient operated on six days after the administration of 125I-labeled biotinylated MoAb and cold avidin, with an optimal tumor-to-normal tissue ratio and with 90% of the circulating radioactivity cleared in two days.

Abdominal Neoplasms↗
PubMedDate not supplied

Radioimmunoguided surgery: clinical experience with different monoclonal antibodies and methods.

The intraoperative detection of tumors by means of a gamma-ray detector that recognized radiolabelled monoclonal antibodies (MoAbs) on tumour cell surfaces has been shown to be feasible and clinically useful. The technology is called the Radioimmunoguided Surgery (RIGS) system. We have been working with this system for five years and in this paper we report our experience using different radiolabelled MoAbs and methods in terms of clinical utility in patients with primary or recurrent colorectal cancer. In the first part of the experience we injected with the MoAb B72.3 a group of 66 patients with primary (36) or recurrent (30) cancer introducing for 7 out of 66 a variation of the method to try to overcome some limits of the original procedure. With the new method, based on the avidin-biotin binding, it is possible to use anti-Cea MoAbs and to reduce the preoperative waiting time, injecting biotinylated MoAbs and avidin. In the second part of the experience, a second group of 15 patients with primary (12) and recurrent (3) cancer was injected with biotinylated MoAbs FO23C5 (anti-Cea) while in a third group of 16 patients, 6 with primary and 10 with recurrent cancer a cocktail of antibodies was used. During surgery a probe (NEOPROBE) was used to count obvious tumor, surrounding normal tissue and to scan the abdomen for areas of increased radioactivity. In the first group of patients tumour was localized by probe in 18/36 (50%) cases of primary cancer and in 24 out of 30 recurrences (80%). In the second group tumour was localized in 8/12 (67%) primary cancers and in 2 out of 3 (67%) recurrences. In the last group primary tumours were localized in 5/6 (83%) patients and recurrent cancer in 7/10 (70%). The method altered the surgical procedure in 2 out of 36 primary tumours (6%) and in 8 out of 30 recurrences (27%) injected with the B72.3. In the group of 15 patients injected with the anti-Cea the method changed the surgical strategy in 2/12 (16%) primaries and in 1 out of 3 recurrences. We had no real clinical utility in the primary cancers injected with cocktails but in 4 out of 10 (40%) patients with recurrent cancer it was possible to localize occult metastatic tissue. In conclusion, the sensitivity of the different MoAbs is similar in the groups even though it is noted that B72.3 seems to be more indicated in recurrent cancers and the FO23C5 in primary tumors.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Monoclonal↗
PubMedDate not supplied

Repeated hepatectomy for colorectal metastasis.

Between January 1981 and December 1995, 12 patients, who previously underwent hepatic resection for colorectal metastases, were selected for a second liver resection for isolated liver recurrence. Mean interval between first and second resection was 16 months. Eight patients had solitary and 4 multiple metastasis. Two major hepatectomies and 11 wedge resections were performed. Mean follow-up was 37 months. No mortality and 33% morbidity was observed. Three and 5-year actuarial survival rates were 71% and 42%, while disease-free survival was 30%. No patient, primary tumour, or metastases' characteristics were significantly associated to survival. Surgical resection is the only therapy that could offer reasonable chance of long term survival and, in selected case, of cure. A careful patients' selection as well as an accurate surgical technique are essential to reduce post operative mortality and morbidity.

Adult↗
PubMedDate not supplied

Pre-operative chemoembolization of hepatocellular carcinoma in cirrhotic patients.

BACKGROUND/AIMS: The aim of the study was to evaluate clinical and pathological effects of transcatheter arterial chemoembolization (TACE) before surgical resection for hepatocellular carcinoma (HCC) in cirrhosis (55 patients); results were compared with a group of 45 patients undergoing surgical resection without TACE. METHODOLOGY: From March 1989 to December 1997, 55 cirrhotic patients, affected by surgically resectable HCC not larger than 5 cm with unifocal or bifocal tumor lesions, underwent TACE pre-operatively. RESULTS: Massive necrosis was observed in 26%, necrosis > 50% in 38% of lesions. Neoplastic cells were found in 47% of cases within the capsule or in the pericapsular tissue. Satellite nodules showed a low rate of necrosis. Mortality and morbidity in the pre-operative TACE group were 1.8% and 29%, respectively, and 4.4% and 33%, respectively, in the control group. One-, 3- and 5-year patient survival rates were 87%, 70% and 39%, respectively, versus 79%, 38% and 19%, respectively (p<0.02), in the control group. Disease-free survival was 40% and 28% at 3 years and 5 years with pre-operative TACE versus 20% and 11% (p<0.05). CONCLUSIONS: Pre-operative TACE can be performed with low morbidity. TACE can necrotize the main lesion and temporarily arrest portal diffusion of neoplastic cells by acting on microvascular infiltration. No evident effect on satellites and pericapsular neoplastic foci was observed. The long-term patients and disease-free survival rates were improved upon.

Aged↗