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G Paganelli

Publications and source records attributed to G Paganelli.

At least 73 records · Page 4Linked to original sources
PubMed1999

Sentinel node localization in primary melanoma: learning curve and results.

Ninety primary melanoma patients were studied to investigate the importance of adopting the simultaneous use of patent blue dye (PBD) and lymphoscintigraphy plus gamma detection probe to locate the sentinel node (SN). In total 135 SNs in 105 basins were visualized preoperatively under a gamma camera after lymphoscintigraphy. When a SN was identified intraoperatively, its radioactivity level and colour were verified and documented. Two of the SNs seen on lymphoscintigraphy were not found. Using PBD 78.52% of the SNs were identified; 95.5% were identified using the gamma detection probe. Using both methods together 98.5% of the SNs were detected. Twenty-two patients (24.4%) had pathologically positive SNs. The surgical learning curve was assessed for the two techniques. The learning curve associated with the methodology was important in finding the SN when using PBD associated with lymphoscintigraphy, but not when the gamma detection probe was used; we found a statistically significant reduction in the percentage of stained SNs found using PBD in the initial 14 SNs biopsied compared with the subsequent 121 nodes. This is important as not all institutions have access to a gamma probe. The time required to identify each SN was documented and analysed. The duration of the procedure was significantly shorter for stained SNs than for non-stained SNs, which support the use of both PBD and the gamma probe. In conclusion, SN biopsy should be performed by surgeons and nuclear medicine doctors in co-operation, both methods being adopted simultaneously to reduce the percentage of procedure failures.

Adolescent↗
PubMed1999

Sentinel node localisation: A new prospective in the treatment of nodal melanoma metastases.

Sentinel node (SN) mapping and biopsy is a procedure that accurately stages the regional lymph node (LN) basin. Defined patterns of lymphatic drainage allow intraoperative determination of the first (sentinel) lymph node in the regional basin, and the absence of metastatic disease in the SN accurately reflects the absence of melanoma in the remaining regional nodes. The use of radiocolloid and a hand-held gamma detecting probe (GDP) together with a vital blue dye provides optimal results, and allows for the successful identification of the SN in over 99% of the procedures. Close collaboration between surgeons, nuclear radiologists and pathologists is required to ensure optimal results. Examination of serially sectioned SNs by hematoxylin-eosin staining (H&E), immunohistochemical staining and perhaps in the near future RT-PCR should reduce the number of patients with missed microscopic melanoma in the regional lymph nodes. Furthermore, the survival benefit recently reported in patients with melanoma metastatic to regional nodes using high dose of interferon alpha-2b signals that the surgeons should aggressively examine patients for the presence of occult regional melanoma metastases. Intraoperative SN mapping and SN biopsy are cost-effective procedures that allows accurate identification of regional lymph nodes that contain metastatic melanoma.

Adolescent↗
PubMed1998

Biochemical characterization and crystal structure of a recombinant hen avidin and its acidic mutant expressed in Escherichia coli.

The mature hen avidin encoded by a synthetic cDNA was expressed in Escherichia coli in an insoluble form. After resolubilization, renaturation and purification, a recovery of about 20 mg/l cell culture was obtained. ELISA assays indicated no apparent differences in biotin binding between the natural and recombinant avidins. In addition, an acidic avidin mutant, bearing the substitutions Lys3-->Glu, Lys9--> Glu, Arg26-->Asp and Arg124-->Leu of four exposed basic residues, was produced. The protein, expressed and renatured as wild-type avidin, showed unaltered biotin-binding activity. The acidic pI (approximately 5.5) and lack of aggregation of the mutant allowed easy electrophoretic analysis under non-denaturing conditions of the protein alone and of its complexes with biotin, biotinylated transferrin or peroxidase. Analysis of the sera from sensitized subjects revealed that the avidin mutant has altered antigenicity. Both recombinant avidins were crystallized and the three-dimensional structures solved by molecular replacement and refined to 0.22 nm resolution. The three-dimensional structures of the two recombinant molecules, in the absence of biotin and of glycosylation, are fully comparable with those of the natural hen avidin previously reported.

Animals↗
PubMed1998

Intraoperative localization of the sentinel node in breast cancer: technical aspects of lymphoscintigraphic methods.

Axillary lymph node dissection is an important part of the surgical treatment of breast cancer as a staging procedure. Recent progressive advances in early detection have led to the treatment of small primary carcinomas; thus, a great number of axillary dissections show completely negative lymph nodes. The sentinel node (SN) concept, developed for melanoma patients, seems to be similarly valid in breast cancer and has the potential to change the standard surgical approach in these patients. To verify the accuracy of lymphoscintigraphic method associated with radioguided biopsy of the sentinel node in a large series of patients, we studied 382 patients with operable breast cancer. Lymphoscintigraphy (LS) was performed the day before surgery; three different-sized ranges of 99mTechnetium-labeled colloid particles were injected either by subdermal or peritumoral administration. Planar scans were registered in anterior and oblique projections, and a cutaneous marker was placed over the skin corresponding to the SN as visualized. SNs were localized and removed during surgery, using a gamma-detecting probe (GDP); total axillary dissection was then performed. In 54 patients, blue dye was also administrated in the tumor bed immediately after excision of the primary. LS identified at least one SN in 377 of 382 cases (98.7%). Axillary SN was localized in 371 cases (97.1%). The overall concordance between SN status and other axillary nodes was 96.8% (359 of 371). Localization of the SN was easier when large-size particles of colloidal albumin were injected in a volume of 0.4 ml. GDP successfully localized SN in 54/54 cases (100%), while blue dye identified SN in 37/54 patients (68.5%). In 33 of 37 cases (89%) the dye and LS identified the same node. LS and GDP-guided surgery provide accurate identification and removal of the SN, particularly when large-size radiolabeled colloids are injected in a small volume.

Axilla↗
PubMed1998

Combined treatment of advanced oropharyngeal cancer with external radiotherapy and three-step radioimmunotherapy.

The prognosis of patients with locally advanced head and neck cancer remains grim due to poor locoregional tumour control. In the attempt to eradicate residual disease, various novel modalities have been tested, among which radioimmunotherapy (RIT) has shown some potential. We present a case of locally advanced oropharyngeal carcinoma successfully treated with a combination of various treatments including surgery, radio-chemotherapy and three-step RIT, with the avidin-biotin pretargeting system. A partial tumour response was achieved after surgery and radio-chemotherapy; persistent disease was documented at computed tomography (CT), ultrasound (US) and immunoscintigraphy (ISG) 10 weeks after the end of chemo-radiotherapy. The good correlation between the tracer localization in the scintigraphic images and residual mass visualized at CT suggested the application of three-step RIT using systemic administration of yttrium-90 (py) biotin. At present, 17 months after RIT, the patient is alive with no evidence of disease as documented by magnetic resonance imaging (MRI) and US. This is the first case of complete clinical remission of a head and neck carcinoma induced by combined treatment including pretargeted RIT with 90Y-biotin.

Aged↗
PubMed1998

Sentinel node localization in cutaneous melanoma: lymphoscintigraphy with colloids and antibody fragments versus blue dye mapping.

In stage I cutaneous melanoma, biopsy of the first tumour-draining lymph node (sentinel node, SN) may replace routine elective lymph node dissection (ELND). The patent blue dye (PBD) technique has been shown to be an original method for the localization of the SN, but its sensitivity is sometimes unsatisfactory, depending on the basin where the SN is located. We compared three methods to locate the SN: intraoperative PBD mapping, lymphoscintigraphy (LS) with an aspecific tracer (colloid) and LS with a specific tracer (monoclonal antibody, MoAb). Fifty patients with cutaneous melanoma were enrolled in this study. The day before surgery LS was performed following an intradermal injection of 55 MBq technetium-99m-labelled HSA colloidal particles (25 patients: group A) or 220 MBq of 99mTc-F(ab')2 MoAb 225.28 S (25 patients: group B) around the site of the primary lesion. In group B an equal amount of tracer was injected, as a control, in the contralateral site. Early and delayed images were acquired with a gamma camera and SN(s) marked on the skin. In all 50 patients the PBD technique was also performed immediately before surgery. When a blue node was identified intraoperatively, its radioactivity level was measured with a gamma probe. In the absence of blue coloration, the probe alone was used to detect the SN. Lymphoscintigraphic visualization of SNs was possible in 50/50 patients (100%), a total of 73 SNs (38 in group A and 35 in group B) were found, distributed in 55 basins. Gamma probe detection (GPD) allowed the identification of SNs in 49/50 patients (98%), and 72 SNs in 54 basins were localized. By contrast, using PBD, SNs were stained only in 40/50 patients (50 SNs in 40 basins). A tumour-positive SN was histologically proven in 13 patients (26%). In group B, no increase uptake was observed in the seven positive SNs (6/25 patients) compared with the contralateral uninvolved nodes. In conclusion this study demonstrates that LS combined with GPD is a safe method for detecting SNs and is more sensitive than the PBD technique. The use of MoAb fragments did not show any advantage over the non-specific tracer.

Adolescent↗
PubMed1998

Biochemical modifications of avidin improve pharmacokinetics and biodistribution, and reduce immunogenicity.

Pretargeting techniques using the avidin-biotin system have shown encouraging results in both diagnostic and therapeutic clinical trials. It has been shown that in cancer therapy the ideal agent to be used for pretargeting should have a plasma half-life longer than avidin and lower immunogenicity than streptavidin in order for these procedures to be applied safely and repeatedly in patients. We prepared a recombinant form of avidin with no carbohydrates and avidins, biochemically modified either by decreasing the positive charges with succinic anhydride or by linking polyethylene glycol (PEG) at three different molar ratios and evaluated their in vivo behaviour after i.p. administration in mice. The succinylation and PEGylation of avidin increased the plasma half-life proportionally to the degree of protein modification. The procedures, however, affected the biotin binding to some extent. The biodistribution studies showed that, for all six time points (ranging from 20 min to 18 h post-injection), the liver and kidney to blood ratios were lower for PEGylated avidins than native, recombinant and succinyl avidin. Recombinant and low PEGylated avidin evoked an immune response in all mice after at least three injections. Native, recombinant and succinyl avidins showed higher serum titres than PEGylated avidins. In conclusion, the conjugation of avidin to PEG chains (n = 7) originates a compound with a suitable blood clearance, low immunogenicity and concurrent low cross-reactivity with avidin.

Animals↗
PubMed1998

[Radiation protection in the use of tracers in radioguided breast surgery].

PURPOSE: Recent techniques in nuclear medicine have permitted to implement new procedures useful in surgery. Among these, the procedures for locating sentinel lymph nodes and nonpalpable breast lesions are of great interest. The protocols for the location of the sentinel lymph node and for the radioguided location of occult lesions developed at the European Institute of Oncology (IEO, Milan) are based on the administration of radiopharmaceuticals labelled with Technetium-99m (99mTc). We evaluated the dosimetric data relative to patients and hospital personnel to assess whether specific radiation protection procedures are needed. MATERIAL AND METHODS: Fifty patients with nonpalpable breast lesions and 50 patients with suspected lymph node involvement were enrolled in this study. All the patients underwent surgery the day after in-loco administration of the radiopharmaceutical (11 MBq of 99mTc). The absorbed dose to the hospital personnel was estimated from the air kerma rate measured by ionization chamber at different distances from the patients at 0 and 16 hours after the radiopharmaceutical administration. In order to evaluate radiation protection for patients, absorbed doses were measured positioning thermoluminescent dosimeters on the patient's skin for about 16 hours. In the operating room, activity was measured on some excised tissues (lymph nodes and tumors) and on surgical instruments. RESULTS: Absorbed doses were very low for the clinical staff also in case of prolonged patient assistance. After 100 cases, the surgeon mean absorbed dose to the hands and mean effective dose were .45 mGy and .09 mGy, respectively. These values correspond to 1% of the annual dose limit to the hands and to 10% of the annual equivalent effective dose recommended for the population (ICRP 60 and law by decree 230/95). The absorbed dose to healthy tissues of the patients were lower than 1 mGy (mean values: contralateral breast: .9 mGy; abdomen .45 mGy). The mean activity detected in the excised tissues was 9 kBq and 900 kBq in the sentinel lymph nodes and in the tumor lesions (injection site), respectively. The activity detected on the surgical instruments, higher on gauzes (< 100 kBq), was negligible. CONCLUSIONS: From the radiation protection point of view, the data support the validity of our protocols. Absorbed doses to the hospital personnel are low and require neither a radiation protection control nor a classification of exposed workers as classes A or B. Special containers for radioactive wastes are necessary in the administration room but not in the operating room, where the levels of possible contamination are negligible.

Breast Neoplasms↗
PubMed1998

Optimized sentinel node scintigraphy in breast cancer.

INTRODUCTION: Axillary lymph node dissection (ALND) represents an important staging procedure in the surgical treatment of breast cancer. However, it may result necessary in tumors of little dimensions because of low percentage of metastatic axillary lymph node (ALN). If a non invasive technique predicted the status of ALN, ALND procedures could be avoided. We carried out this study i) to establish the best technique to perform the lymphoscintigraphy for detecting the sentinel node in breast cancer and ii) to determine whether a clear sentinel node reliably predicts a disease free axilla. METHODS: 215 patients were submitted to the lymphoscintigraphy before surgery. Three different colloidal radiotracers with particle size ranging between < 50 and 1000 nm were injected sudermically or peritumorally. Early and late images were recorded in anterior and oblique projections and the SN was marked on the skin and biopsied using a gamma detection probe (GDP) during surgery. RESULTS: The SN was identified in 210/215 cases (97.6%). The SN accurately predicted axillary ALN status in 204/210 (97.1%) patients in whom a sentinel node was identified and in all the cases (45 patients) with tumor < 1.5 cm in diameter. In 38/101 cases with metastatic axillary nodes (37.7%) the only positive node was the SN. CONCLUSIONS: Lymphoscintigraphy can easily locate the SN in breast cancer. SN detection resulted easier when large size microcolloids were used. Subdermally administration appeared the best way of injection for palpable lesions. Breast cancer patients without clinical involvement of the axilla should undergo SN biopsy routinely and this may allow sparing complete axillary dissection when the SN is free of disease.

Antimony↗
PubMed1998

Lymphoscintigraphy and radioguided biopsy of the sentinel axillary node in breast cancer.

UNLABELLED: Lymphoscintigraphy associated with radioguided biopsy of the sentinel node (SN) is well established in clinical practice for melanoma. In breast cancer, the SN concept is similarly valid, and lymphoscintigraphy is a useful method for localizing the axillary SN. The aim of this study was to optimize the lymphoscintigraphy technique in association with a gamma ray detecting probe (GDP) for identifying and removing the SN in breast cancer patients. METHODS: Two-hundred fifty patients with operable breast tumor underwent lymphoscintigraphy before surgery. Three different size ranges of 99mTc-labeled colloid particles (<50, <80 and 200-1000 nm) were used, with either subdermal (above tumor) or peritumoral injection. Early and late scintigraphic images were obtained in anterior and oblique projections, and the skin projection of the detected SN was marked. Sentinel nodes were identified and removed with the aid of the GDP during breast surgery; they were tagged separately. Complete axillary dissection followed. In 40 patients, a blue dye was also administered in addition to subdermal radiolabeled colloid to compare blue dye mapping with lymphoscintigraphy localization. RESULTS: Lymphoscintigraphy successfully revealed lymphatic drainage in 245 of 250 patients (98%). The axillary SN was identified in 240 patients (96%). SN biopsy correctly predicted axillary node status in 234 of 240 patients (97.5%). Lymphoscintigraphy and GDP detected the SN most easily and consistently when 200-1000 nm colloid was administered subdermally in an injection volume of 0.4 ml. Blue dye mapping was successful in 30 of 40 patients (75%). In 26 of these patients, the dye and lymphoscintigraphy identified the same node; in 4 cases different nodes were identified. None of these four patients had axillary disease. CONCLUSION: Lymphoscintigraphy is a simple procedure that is well tolerated by patients. Sentinel node identification is more reliable when large-size radiolabeled colloids are injected in a relatively small injection volume (0.4 ml). Use of a GDP greatly facilitates precise pinpointing and rapid removal of the SN.

Antimony↗
PubMed1997

Sentinel-node biopsy to avoid axillary dissection in breast cancer with clinically negative lymph-nodes.

BACKGROUND: Axillary lymph-node dissection is an important staging procedure in the surgical treatment of breast cancer. However, early diagnosis has led to increasing numbers of dissections in which axillary nodes are free of disease. This raises questions about the need for the procedure. We carried out a study to assess, first, whether a single axillary lymph node (sentinel node) initially receives malignant cells from a breast carcinoma and, second, whether a clear sentinel node reliably forecasts a disease-free axilla. METHODS: In a consecutive series of 163 women with operable breast carcinoma, we injected microcolloidal particles of human serum albumin labelled with technetium-99m. This tracer was injected subdermally, close to the tumour site, on the day before surgery, and scintigraphic images of the axilla and breast were taken 10 min, 30 min, and 3 h later. A mark was placed on the skin over the site of the radioactive node (sentinel node). During breast surgery, a hand-held gamma-ray detector probe was used to locate the sentinel node, and make possible its separate removal via a small axillary incision. Complete axillary lymphadenectomy was then done. The sentinel node was tagged separately from other nodes. Permanent sections of all removed nodes were prepared for pathological examination. FINDINGS: From the sentinel node, we could accurately predict axillary lymph-node status in 156 (97.5%) of the 160 patients in whom a sentinel node was identified, and in all cases (45 patients) with tumours less than 1.5 cm in diameter. In 32 (38%) of the 85 cases with metastatic axillary nodes, the only positive node was the sentinel node. INTERPRETATION: In the large majority of patients with breast cancer, lymphoscintigraphy and gamma-probe-guided surgery can be used to locate the sentinel node in the axilla, and thereby provide important information about the status of axillary nodes. Patients without clinical involvement of the axilla should undergo sentinel-node biopsy routinely, and may be spared complete axillary dissection when the sentinel node is disease-free.

Adult↗
PubMed1997

Tumor cell targeting with antibody-avidin complexes and biotinylated tumor necrosis factor alpha.

Tumor pretargeting with biotinylated antibodies and avidin, followed by a delayed delivery of radioactive-labeled biotin, is currently used for in vivo diagnosis and therapy in cancer patients. Herein, we describe the use of a three-step antibody/avidin targeting approach to increase the local concentration and the persistence of biotinylated human tumor necrosis factor alpha (bio-TNF) on a mouse tumor. Mouse RMA lymphoma cells were transfected with the Thy 1.1 allele (RMA-Thy 1.1) to generate a unique tumor-associated antigen. In vitro pretargeting of RMA-Thy 1.1 cells with the biotinylated anti-Thy 1.1 monoclonal antibody 19E12 (bio-19E12) and NeutrAvidin increased the amount of bio-TNF that bound to the cell (10-20 times in comparison with non-pretargeted cells), as well as its half-life on the surface (>30 times). Furthermore, cell pretargeting reduced by more than 2 orders of magnitude the LD50 of bio-TNF in a cytolytic assay with actinomycin D. Finally, RMA-Thy 1.1 cells, pretreated in vitro with bio-TNF according to the three-step procedure and injected into syngeneic C57/BL6 mice, were less tumorigenic than controls. These results indicate that the three-step targeting approach markedly increases the amount and the persistence of bio-TNF on the cell surface and that cell-bound bio-TNF can trigger cytolytic effects in vitro and antitumor effects in vivo. Tumor pretargeting with biotinylated antibodies and avidin could be a novel strategy for increasing the therapeutic index of TNF.

Animals↗
PubMed1997

Combination of monoclonal antibodies for radioimmunoguided surgery.

The use of a cocktail of monoclonal antibodies in intraoperative radioimmunodetection of colorectal tumour has been evaluated in 14 patients. Eight patients had primary and six recurrent colorectal cancer. Three different monoclonal antibodies were used included B72.3, recognizing TAG72 antigen, FO23C3 and FO23C5 directed against two epitopes of CEA. The antibodies were labeled with 125I. During surgery the radioactive emission of tumour and normal tissue was evaluated by a gamma detecting probe. Ten patients showed positive intraoperative results and in particular 6 (75%) of the 8 patients with primary tumour and 4 (67%) of the 6 patients with recurrence, with a mean tumour to normal tissue ratio of 2.2. Intraoperative radioimmunodetection was instrumental in modifying the therapeutic approach in two patients with recurrent cancer but in none of the patients with a primary presentation. Immunohistochemical analysis, to evaluate TAG72 and CEA antigen expression, was performed in 13 cases. CEA antigen was expressed in 8/13 cases and TAG72 in 5/13. Thus the sensitivity was 38.5% and 61.5% with B72.3 and anti-CEA monoclonal antibodies respectively, while in combination the sensitivity was 71.4%. The use of a cocktail of different antibodies improved the sensitivity of intraoperative radioimmunodetection of colorectal tumours, when compared with a single antibody injection. This approach might improve the clinical use of radioimmunodetection.

Adult↗