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L Troncone

Publications and source records attributed to L Troncone.

At least 37 records · Page 2Linked to original sources
PubMed1995

In vitro and in vivo studies with no-carrier added radioiodinated MIBG.

An important drawback of radioiodinated MIBG prepared by isotopic exchange (maximum specific activity: 100 Ci/mmol) is that a considerable amount of carrier is present in the "ready to use" radiopharmaceutical, thus affecting MIBG uptake in the target cells. To improve the therapeutic utility of MIBG an interesting method was developed for the no-carrier-added (n.c.a.) radioiodination of MIBG via a halodesilylation reaction using 3-trimethylsilybenzylguanidine (TMSBG) as precursor. In order to investigate its possible clinical usefulness, n.c.a. [125I]- and [131I]MIBG was prepared according this procedure. HPLC analysis of the labeling mixture showed that the labeling yield reached values greater than 98% within 20 minutes at 70 degrees C. HPLC fraction containing [131I]MIBG was then recovered and tetrahydrofurane was removed under nitrogen stream. Biodistribution studies were performed in BALB/c normal mice and compared with those obtained using [131I]MIBG prepared by isotopic exchange. Preliminary results showed that at 4 hours myocardial uptake was significantly higher than that of c.a. MIBG (20.3 +/- 0.4 %ID/g). Adrenal uptake gradually increased over time; at 24 hours adrenal uptake was almost twofold that a 1 hour. MIBG uptake was also studied in the human neuroblastoma cell line SH-SY5Y which has a specific uptake system for MIBG. The kinetic parameters for MIBG in this line are: km = 0.27 +/- 0.03 microM, Vmax = 39.5 + 1.8 pmol/10(6) cell/10 min. Preliminary data from in vitro binding studies showed that significantly higher levels of specifically incorporated radioactivity can be achieved using n.c.a. [125I]MIBG instead of c.a. [125I]MIBG.

3-Iodobenzylguanidine↗
PubMed1995

Radiolabeled somatostatin analog scintigraphy in medullary thyroid carcinoma and carcinoid tumor.

The aim of this study was to evaluate the effectiveness of a recently developed radiolabelled somatostatin analog (111In-pentetreotide) for the detection and localization of both medullary thyroid carcinoma (MTC) and carcinoid tumors, and to compare the results obtained with the results of 99mTc(V)-DMSA, and radioiodinated MIBG imaging. 111In-pentetreotide scintigraphy was performed in 9 patients with MTC and in 9 patients with carcinoid tumor. Whole body and SPECT studies were performed at 4 and 24 hours post-injection. SMS scintigraphy gave a positive result in 5 out of 7 patients with proven MTC lesions, and in 7 out of 9 patients with known lesions of carcinoid tumor. It gave a negative result in 2 MTC patients with high levels of calcitonin but with no evidence of disease at conventional diagnostic modalities. The scintigraphic results were comparable with those obtained with 99mTc(V)-DMSA in MTC and were superior to those of radioiodinated MIBG in both MTC and carcinoid tumors. When compared with the modifications of calcitonin levels brought about by the acute administration of octreotide ("Octeotride test"), these correlated well in 8 out of 9 patients studied.

3-Iodobenzylguanidine↗
PubMed1994

Nuclear medicine imaging in pediatric oncology.

Nuclear medicine imaging techniques, whether applied in the initial diagnosis or in assessing the response to therapy, are indispensable in the evaluation of malignant diseases that afflict infants and children. The major role of these techniques (bone, 67Ga and 201Tl scintigraphy, imaging with labeled leucocytes, immunoscintigraphy) is that of complementing, in an essential manner, other first choice diagnostic investigations (radiological, bioptic, etc.) such as in evaluating malignant skeletal tumors, soft tissue sarcomas, lymphomas, leukemia and histiocytosis X. Nevertheless, due to their high tissue specificity and/or diagnostic reliability, 99mTc-MDP (or analogues) imaging in the screening of bone metastases, 123/131I-MIBG scintigraphy in the diagnosis and management of neuroblastoma and 131I whole body scan in staging postoperatively differentiated thyroid cancers are proposed as first choice modalities. Well established (131I therapy) or recently developed (131I-MIBG therapy and radioimmunotherapy) therapeutic modalities are available today to be either integrated with or to substitute the conventional treatment of differentiated thyroid carcinoma and neuroblastoma.

3-Iodobenzylguanidine↗
PubMed1994

[Contribution of nuclear medicine to the diagnosis of silent adrenal masses].

The role of adrenal scintigraphy in the noninvasive characterization of silent adrenal masses was investigated in 40 patients. The mass had been detected by US or CT performed in the evaluation of non-malignant extra-adrenal diseases (25 cases) or during staging or follow-up of a malignant extra-adrenal neoplasm (15 cases). In all cases radio-cholesterol scintigraphy (74 MBq i.v. of 131I-6 beta-iodomethylnorcholesterol in 19 cases; 11 MBq i.v. of 75Se-6 beta-selenomethylnorcholesterol in 21 cases) was performed; in 7 cases also 131I-MIBG scan (18.5-37 MBq i.v.) was carried out. When compared with CT data, radiocholesterol scintigraphy (standard or after suppression with dexamethasone) showed: concordant uptake (increased uptake of radiocholesterol on the side of the adrenal mass) in 24/26 patients with adrenal cortical adenoma; discordant uptake (absent or decreased uptake on the side of the adrenal mass) in 12 patients: 5 with adrenal metastases and 7 with non-adenomatous benign space-occupying lesions (2 ganglioneuromas, 1 post-traumatic hemorrhagic lesion, 3 adrenal cysts, 1 myelolipoma); indeterminate uptake (symmetric bilateral uptake) in 4 patients: 2 with a small adenoma, 1 with adrenal metastasis and 1 with a "false incidentaloma" (hepatic regenerative nodule). The results confirm the utility of radiocholesterol scintigraphy in demonstrating the benignity of adrenal lesions (particularly in identifying adrenocortical adenomas) and assess its place among the procedures used to characterize silent adrenal masses. The possible use of MIBG scintigraphy is also discussed.

Adrenal Gland Diseases↗
PubMed1993

Critical observations on neuroblastoma treatment with 131-I-metaiodobenzylguanidine at diagnosis.

Results of treatment with 131-I-Metaiodobenzylguanidine (131-I-MIBG) in patients with resistant neuroblastoma appear encouraging if one considers that most of the patients had far advanced, intensively pre-treated disease. To further explore the potential role of this new drug in untreated patients, we treated 3 children with stage III neuroblastoma. All three of our cases received 131-I-MIBG at relatively low dose with the complete disappearance of the tumor mass in case 1, whereas in cases 2 and 3 CT scan showed a significant reduction of the tumor mass and, interestingly enough, no evidence of 131-I-MIBG uptake of a tracer dose in the remaining tumor. Particularly, in case 2, the persistence and subsequent progression of part of the tumor mass without 131-I-MIBG uptake after a therapeutic dose of 131-I-MIBG, which apparently destroyed the 131-I-MIBG-positive cell population, clearly suggest heterogeneity at diagnosis, with a dual neuroblastoma cell population, one with 131-I-MIBG uptake and the other without. Besides the biological implications of the 131-I-MIBG uptake heterogeneity in neuroblastoma at diagnosis, our findings suggest that in stage III neuroblastoma patients even a relatively small dose of 131-I-MIBG administered at diagnosis is sufficient to destroy either the primary tumor completely (case 1) or the part of the tumor (case 2 and 3) which shows 131-I-MIBG uptake, without any significant hematologic toxicity. Furthermore, a single course of 131-I-MIBG at the dosage employed does not appear to jeopardize the subsequent use of chemotherapy. In conclusion, if our data are confirmed by further investigation, 131-I-MIBG may be included as a front line drug shortly followed by chemotherapy in future treatment strategies of advanced neuroblastoma without or with minimal bone marrow infiltration.

3-Iodobenzylguanidine↗
PubMed1993

Incidentally discovered adrenal masses: a functional and morphological study.

In the last two years we have examined 17 consecutive patients (11 females and 6 males, 20-66 years old) in whom an unsuspected adrenal mass was discovered by ultrasonography or computed tomography performed for unrelated reasons. Pathological diagnosis was available in 11 cases based on surgical excision in 9 (2 pheochromocytomas of 5 and 12 cm in diameter; 2 ganglioneuromas of 5 and 6 cm; and 5 benign cortical adenomas between 3 and 5 cm), autopsy in 1 (a disseminated malignant pheochromocytoma of 16 cm) and fine-needle biopsy in 1 (a pseudo-adrenal mass of 6 cm, that was a regenerative hepatic nodule). The remaining 6 non histologically diagnosed masses were less than 3 cm in diameter. Endocrine studies showed elevated urinary excretion of catecholamines, vanillylmandelic acid and metanephrines in the pheochromocytomas and borderline high values in ganglioneuromas. A low plasma renin activity was encountered in 2 operated cortical adenomas and 3 non operated incidentalomas. In 2 of the latters aldosterone serum levels were elevated and the final diagnoses respectively were Conn's adenoma and dexamethasone-suppressible hyperaldosteronism with bilateral nodular hyperplasia. An inappropriate cortisol secretion was documented in a cortical adenoma removed. Radio-cholesterol scintiscan showed unilateral or increased uptake on the side of adrenal mass (concordant uptake) in the 5 benign cortical adenomas removed and in 4 non operated incidentalomas. A decreased uptake on the side of the adrenal mass (discordant uptake) was found in the 2 ganglioneuromas while an indeterminate bilateral uptake was found in the 2 remaining non operated incidentalomas and in the pseudo-adrenal mass.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗
PubMed1993

Thyrotoxicosis due to ectopic retrotracheal adenoma treated with radioiodine.

Ectopic thyroid tissue is rarely found in the cervical retrotracheal region and its functional autonomy with suppression of the normal gland can be considered unusual. We report a case of thyrotoxicosis in a patient who had no palpable goitre in the neck but was found to have a solitary toxic thyroid nodule behind the trachea. US and CT scanning confirmed that the nodule was retrotracheal and apparently was not continuous or contiguous with the normal thyroid gland. The toxic adenoma showed avid uptake of iodine-131 (131I), and using thallium-201-chloride (201Tl)-SPECT the normal thyroid gland together with the retrotracheal autonomous nodule was demonstrated. The patient underwent radiometabolic therapy with 666 MBq of 131I and a 131I scan performed 6 months later showed only the previously suppressed normal thyroid gland.

Adult↗
PubMed1991

Autonomously functioning thyroid adenoma in a seven year old boy.

Hyperfunctioning thyroid adenoma is an extremely rare disorder in childhood. A case of a seven year old boy is reported. Clinical and laboratory findings were similar to those seen in adults. Recovery of thyroid function was prompt after ablative surgery and no substitutive therapy was required.

Adenoma↗
PubMed1990

Role of immunoscintigraphy in clinical assessment of gastrointestinal tumors.

From June 1986 until April 1989 31 patients with gastrointestinal tumors were studied at follow-up for recurrences by immunoscintigraphy (IS) using F(ab)2 fragments of monoclonal antibodies anti CEA and anti CA 19-9. IS was employed to confirm the presence of metastases already found (group A) and to verify metastases suspected following physical and instrumental examinations and/or increases in CEA and/or CA 19-9 (group B). Thirty-four IS findings have been evaluated to date: 19 in group A, with 18 true positive and 1 false negative results; 15 in group B. In these patients there were 12 cases of pathologic high fixation: 6 were confirmed using standard examinations after a median follow-up of 1 month (range 1-12); 6 cases had no metastatic evolution at the suspected site after a follow-up of 5-28 months. In 3 cases IS was negative, these patients are disease free at 13, 14 and 24 months. In group B, 5 of 8 abdominal intense fixations were early diagnoses of local or peritoneal recurrences. The overall accuracy was 79.4% and it was not affected by circulating CEA levels; sensitivity was 96%. IS can be considered useful as a primary diagnostic examination in the follow-up of patients with suspected abdominal metastases.

Adult↗
PubMed1990

Thyroid carcinoma mimicking a toxic adenoma.

A young woman with a thyroid papillary carcinoma behaving as an autonomously hyperfunctioning nodule is described. Only 17 similar patients have been seen in the past 25 years. It is emphasized that hyperthyroidism does not exclude malignant disease in hot nodules. This possibility suggests that all thyroid nodules, either cold or hot, require careful management. Therefore, in "at risk" cases, surgery could be the most useful treatment.

Adenoma↗
PubMed1990

The diagnostic and therapeutic utility of radioiodinated metaiodobenzylguanidine (MIBG). 5 years of experience.

The authors' experience of more than 5 years in the diagnostic and therapeutic use of radioiodinated MIBG in neural crest tumors is reported. 123I/131I-MIBG scintigraphy was performed in 158 patients: 75 suspected (24 proven) pheochromocytomas (pheos), 43 neuroblastomas (NB), 20 medullary thyroid carcinomas (MTC), 6 ganglioneuromas, 5 carcinoids and 1 insulinoma. Eight cases of tumors not originating from the neural crest were also investigated. The diagnostic sensitivity of the method was above 90% both in pheos and NB (primary tumors and bone metastases). The examination was less effective in localizing MTC (sensitivity = 64.4% in primary or residual/recurrent tumors). The scintigraphic outcome was negative in ganglioneuromas, carcinoids and insulinoma. Specificity was very high (greater than 95%), and no false positive results were found in tumors not deriving from the neural crest. 131I-MIBG treatment was administered to four patients with malignant pheo, nine with NB and four with MTC. Therapy resulted in a complete response in one pheo, two NB and one MTC treated after surgery or at diagnosis (one NB); it gave partial response and prolonged remission in five advanced cases (one pheo, two NB and two MTC); it resulted in temporary stabilization of the disease in one pheo and two NBs; it was ineffective in four cases.

3-Iodobenzylguanidine↗
PubMed1989

131I-metaiodobenzylguanidine in the treatment of neuroblastoma at diagnosis.

Radioactive metaiodobenzylguanidine (131I-MIBG) is taken up specifically by neuroblastoma cells and appears to represent a new treatment modality in patients with advanced neuroblastoma. Taking into account the fact that all patients so far treated were heavily pretreated and resistant to chemotherapy, the results obtained appear encouraging. In order to explore further the potential role of this new drug in untreated patients, we treated with 131I-MIBG a child with stage III neuroblastoma at diagnosis. We observed the complete disappearance of a large abdominal tumor mass after a relatively low dosage of 131I-MIBG, with minimal hematologic toxicity. No further treatment was given and, at present, the patient is alive with no evidence of disease 18 months from diagnosis. This child represents, to our knowledge, the only case of neuroblastoma thus far treated at diagnosis and the excellent response obtained suggests the need for further investigations of this therapy in untreated patients.

3-Iodobenzylguanidine↗
PubMed1989

Diagnostic and therapeutic potential of new radiopharmaceutical agents in medullary thyroid carcinoma.

Recently developed radiopharmaceuticals have been proposed for imaging medullary thyroid carcinoma (MTC) with some having therapeutic potential. This study compares the imaging results obtained with radioiodinated meta-iodo-benzylguanidine (MIBG), 99mTc (V) DMSA, and 131I F(ab')2 anti-carcinoembryonic antigen (anti-CEA) in a group of MTC patients. In 23 patients 131I MIBG imaging showed a high specificity (no false-positive results) but a less satisfactory sensitivity (50%). In 12 patients 99mTc (V) DMSA revealed a better sensitivity (77%) but a lower specificity (three false-positive results). Positive results were obtained in two of three patients studied with 131I F(ab')2 anti-CEA. These data suggest that the highly sensitive 99mTc (V) DMSA should be considered as a first choice procedure followed by the highly specific radioiodinated MIBG to confirm the initial results. Since radioiodinated MIBG imaging may have therapeutic usefulness, 131I MIBG was evaluated in an integrated treatment protocol in four cases of proven MTC. The preliminary results obtained were encouraging.

3-Iodobenzylguanidine↗
PubMed1988

The possible use of radioiodinated metaiodobenzylguanidine (MIBG) in medullary thyroid carcinoma.

The value of radioiodinated metaiodobenzylguanidine (MIBG) in imaging thyroid medullary carcinoma (MTC) was investigated (18 studies) in 12 patients with proven MTC. Calcitonin (CT), carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) were also determined. The patients were divided into two groups. Group I comprised 7 patients who had relapsed; two of them were also studied before total thyroidectomy. In the 2 cases studied before total thyroidectomy 123/131I-MIBG imaged the primary tumor (partially) and the residual tumor involved lobe. The residual/recurrent tumor present in 4 and some of the remote metastases in 3 out of 5 were detected. Group II includes 5 patients studied postoperatively with no evidence of disease. A residual tumor in one of the 2 patients without evidence of disease on the basis of conventional diagnostic modalities but with elevated tumor markers was visualized; the outcome was correctly negative in 3. One patient underwent treatment with 131I-MIBG. A total dose of 27.1 GBq (733 mCi) was given. Relief of pain and partial regression of the lesions was achieved.

3-Iodobenzylguanidine↗