Screening in asymptomatic SDHx mutation carriers: added value of ¹8F-FDG PET/CT at initial diagnosis and 1-year follow-up.

PURPOSE: Specific recommendations on screening modalities for paraganglioma (PGL) and phaeochromocytoma (PCC) in asymptomatic SDHx mutation carriers (relatives) are still lacking. We evaluated the added value of (18)F-FDG PET/CT in comparison with morphological imaging at initial diagnosis and 1 year of follow-up in this population. METHODS: The study included 30 consecutive relatives with a proven SDHx mutation who were investigated by (18)F-FDG PET/CT, gadolinium-enhanced magnetic resonance angiography of the head and neck, thoracic/abdominal/pelvic (TAP) contrast-enhanced CT and/or TAP MRI. (123)I-MIBG scintigraphy was performed in 20 subjects and somatostatin receptor scintigraphy (SRS) in 20 subjects. The gold standard was based on pathology or a composite endpoint as defined by any other positive imaging method and persistent tumour on follow-up. Images were considered as false-positive when the lesions were not detected by another imaging method or not confirmed at 1 year. RESULTS: At initial work-up, an imaging abnormality was found in eight subjects (27%). The final diagnosis was true-positive in five subjects (two with abdominal PGL, one with PCC and two with neck PGL) and false-positives in the other three subjects (detected with (18)F-FDG PET/CT in two and TAP MRI in one). At 1 year, an imaging abnormality was found in three subjects of which one was an 8-mm carotid body PGL in a patient with SDHD mutaion and two were considered false-positive. The tumour detection rate was 100% for (18)F-FDG PET/CT and conventional imaging, 80% for SRS and 60% for (123)I-MIBG scintigraphy. Overall, disease was detected in 4% of the subjects at the 1-year follow-up. CONCLUSION: (18)F-FDG PET/CT demonstrated excellent sensitivity but intermediate specificity justifying combined modality imaging in these patients. Given the slow progression of the disease, if (18)F-FDG PET/CT and MRI are normal at baseline, the second imaging work-up should be delayed and an examination that does not expose the patient to radiation should be used.

Occult nodal metastases in T1-T2cN0 oral squamous cell carcinoma: Correlation between sentinel node positivity and completion neck dissection analysis.

OBJECTIVES: Sentinel node procedure (SN) is a standard procedure that has shown its safety and effectiveness for T1/T2 cN0 oral squamous cell carcinoma (OSCC), with completion neck dissection (CND) for patients with positive SN. The aim of this study was to characterize the nodal involvement in a cohort of SN + OSCC. MATERIALS AND METHODS: Patients with T1/T2 cN0 OSCC with positive SN with CND were included in this single-center, prospective cohort study between 2000 and 2013. RESULTS: 54/301 patients had at least one positive SN. In 43/54 (80 %) cases, only the SN(s) were invaded; with only one SN involved (SN+=1) in 36/54 (67 %) cases. No predictive factors of nodal involvement in the CND were found considering the followings: SN micro/macrometastases, primary tumor's depth of invasion (DOI), perineural spread, lymphovascular involvement, primary tumor location, T stage and extranodal extension. The SN micrometastatic involvement (n = 22) was significantly associated with only one SN + CND- (p = 0.017). In the group of patients with unique micrometastatic involvement in the SN (n = 20/54), there was a higher isolated nodal recurrence free time (p = 0.017). CONCLUSION: 80% of T1/T2 cN0 OSCC with positive SN had no other lymph node metastases in the CND, questioning the potential benefits of this procedure. Predictive factors such as the size of the SN metastasis need to be tested to stratify the risk of positive non-SN lymph nodes leading to a personalized treatment, lowering the therapeutic morbidity while maintaining the oncologic safety.

Prediction and diagnosis of bone metastases in well-differentiated gastro-entero-pancreatic endocrine cancer: a prospective comparison of whole body magnetic resonance imaging and somatostatin receptor scintigraphy.

PURPOSE: Our purpose was to compare the sensitivity of whole body (WB) magnetic resonance imaging (MRI) and somatostatin receptor scintigraphy (SRS) for the diagnosis of bone metastases (BMs) in patients with well-differentiated gastro-entero-pancreatic endocrine cancer (WD-GEP-EC) and to determine predictive factors of BM. PATIENTS AND METHODS: WB-MRI and SRS were prospectively performed in 79 patients with bronchial (11), thymic (five), gastric (two), duodeno-pancreatic (24), ileal (26), colic (one), or unknown primary (10) WD-GEP-EC. RESULTS: A total of 36 patients (46%) had 333 BMs involving 119 skeletal segments. WB-MRI and SRS were equally sensitive for detecting patients with BM (86 vs. 81%; P = 0.56), with 33% of the patients diagnosed with only one procedure. WB-MRI detected more BMs than SRS (80 vs. 57%; P = 0.017). Compared with SRS, WB-MRI detected more spine BMs (96 vs. 45%; P < 0.001) and tended to detect more pelvic and lower limb BMs (P = 0.054 and P = 0.06, respectively). Compared with WB-MRI, SRS detected more skull BMs (100 vs. 0%; P < 0.001) and tended to detect more rib BMs (P = 0.08). Sternal and upper-limb BMs were equally detected with WB-MRI and SRS (P = 0.32 and P = 0.46, respectively). Bone staging with SRS and spine MRI rather than WB-MRI would have detected 92% of the patients with BMs and 83% of all BMs. The extent of liver involvement and bronchial-thymic primary tumors were independent predictive factors for BM. CONCLUSIONS: We recommend bone staging with SRS and spine MRI in all patients with bronchial-thymic or unknown primary WD-GEP-EC. In case of duodeno-pancreatic or ileal primary, bone imaging may be restricted to patients with liver metastases.

Sentinel node biopsy in early oral squamous cell carcinomas: Long-term follow-up and nodal failure analysis.

OBJECTIVES: Evaluate the reliability of sentinel node biopsy (SNB) in T1/T2 cN0 oral squamous cell carcinoma (OSCC), and compare recurrence-free time (RFT) and overall survival (OS) between patients undergoing SNB and neck dissection (ND). PATIENTS AND METHODS: Patients with T1/T2 cN0 OSCC underwent SNB followed by systematic ND in the first cohort and SNB followed by selective ND in case of positive sentinel nodes (SN) in the second cohort. RESULTS: A total of 229 patients were followed (first cohort 50, second cohort 179). SNs were successfully detected in 93.9% (215/229) of cases. Median follow-up was 5.6 years. Recurrence occurred in 38/215 patients, with isolated nodal recurrence in 18/215 patients. At 5 years, the rate of recurrence-free patients was 80.0% and the rate of patients without isolated nodal recurrence was 90.4%. Negative predictive value of SNB was 92.7%. No statistically significant difference was observed between the two groups regarding RFT and OS. In 83% (10/12) of ipsilateral isolated nodal recurrences, primary tumor was located in anterior part of oral cavity. Only 43% (3/7) of SN+ patients with nodal recurrence were eligible for salvage surgery, compared to 91% (10/11) of SN- patients. SNB resulted in fewer complications than ND (8% vs 28%, p < 0.0001). CONCLUSION: SNB is a reliable staging tool for T1/T2 cN0 OSCC, without adverse effect on patient survival and fewer complications. No late recurrences occurred in long-term follow-up. Close follow-up is mandatory for SN+ patients, who are at higher risk of nodal recurrence and have worse prognosis.

Diagnostic and prognostic value of 18-fluorodeoxyglucose positron emission tomography in adrenocortical carcinoma: a prospective comparison with computed tomography.

OBJECTIVE: Patients with adrenocortical cancer are submitted to multiple imaging procedures for diagnosis of recurrence and staging. The aim of this prospective study was to evaluate the diagnostic and prognostic values of fluorodeoxyglucose (FDG) using a combined positron emission tomography and computed tomography (PET/CT) modality, compared with thoracoabdominopelvic computed tomography (TAP-CT). METHODS: Twenty-eight consecutive patients with adrenocortical cancer referred from November 2003 to December 2004 to the Institut Gustave Roussy were included. Mean time between PET/CT and TAP-CT was 16 d. Independent readers analyzed images of each modality. The gold standard was progression on follow-up TAP-CT or pathology. RESULTS: A total of 269 lesions in 57 organs were depicted in 22 patients. The sensitivities for the detection of distinct lesions and the diagnosis of metastatic organs were 90 and 93% for PET/CT and 88 and 82% for TAP-CT, respectively. Twelve percent of the lesions were seen on PET/CT only and 10% on TAP-CT only. Eighteen percent of the metastatic organs were diagnosed with PET/CT only and 7% with TAP-CT only. Thirty-eight percent of the local relapses were seen only with PET/CT. PET/CT depicted three false-positive lesions. Treatment modalities were modified by PET/CT findings in five cases among which one was falsely positive. Tumor size and mitotic rate were significantly associated with FDG uptake. The intensity of FDG uptake (maximum standardized uptake value > 10) and the volume of FDG uptake (>150 ml) were significant prognostic factors for survival. CONCLUSIONS: We show that FDG-PET/CT is complementary to TAP-CT and of special interest in the diagnosis of local relapses.

Long-term outcome of 444 patients with distant metastases from papillary and follicular thyroid carcinoma: benefits and limits of radioiodine therapy.

AIM: The goal of this study was to estimate the cumulative activity of (131)I to be administered to patients with distant metastases from thyroid carcinoma. METHODS: A total of 444 patients were treated from 1953-1994 for distant metastases from papillary and follicular thyroid carcinoma: 223 had lung metastases only, 115 had bone metastases only, 82 had both lung and bone metastases, and 24 had metastases at other sites. Treatment consisted of the administration of 3.7 GBq (100 mCi) (131)I after withdrawal of thyroid hormone treatment, every 3-9 months during the first 2 yr and then once a year until the disappearance of any metastatic uptake. Thyroxine treatment was given at suppressive doses between (131)I treatment courses. RESULTS: Negative imaging studies (negative total body (131)I scans and conventional radiographs) were attained in 43% of the 295 patients with (131)I uptake; more frequently in those who were younger, had well-differentiated tumors, and had a limited extent of disease. Most negative studies (96%) were obtained after the administration of 3.7-22 GBq (100-600 mCi). Almost half of negative studies were obtained more than 5 yr after the initiation of the treatment of metastases. Among patients who achieved a negative study, only 7% experienced a subsequent tumor recurrence. Overall survival at 10 yr after initiation of (131)I treatment was 92% in patients who achieved a negative study and 19% in those who did not. CONCLUSION: (131)I treatment is highly effective in younger patients with (131)I uptake and with small metastases. They should be treated until the disappearance of any uptake or until a cumulative activity of 22 GBq has been administered. In the other patients, other treatment modalities should be used when tumor progression has been documented.

[Role and perspectives of sentinel node biopsy in head and neck tumors]. / Place et perspectives du ganglion sentinelle dans les tumeurs des voies aérodigestives supérieures.

PURPOSE: To evaluate the accuracy of sentinel node biopsy for assessing the neck status for those patients with squamous cell carcinoma T1T2N0 of oral cavity. PATIENTS AND METHODS: 55 patients were included in a prospective study between 2000 and 2003. 53 underwent a sentinel node biopsy (SNB) followed by an elective neck dissection (END). Pathological examination with stepped serial sectioning and immunohistochemistry of sentinel node (SN) has been compared with routine pathology examination of remaining END nodes. RESULTS: 12 patients had a positive SN. No false negative was found. Patient follow up on, at less of 3 years, did not show any node recurrence for those patients with negative SN. After that study, 44 patients had a SNB without END. 7 patients had a positive SN. Follow up showed a node recurrence for 3 patients. In two of these, pathological reexamination showed a micrometastase in SN. SN failure rate is less than 3% for those 99 patients. CONCLUSION: SNB is a liable procedure. Failure rate is the same as in END. We plan to use this procedure in orophyngeal tumors where it could be possible to reduce irradiation fields and treatment sequels for those patients with negative SN.

Tumor localization in patients by radiolabeled monoclonal antibodies against colon carcinoma.

A radiolabeled monoclonal antibody (MAb) that has been shown to react specifically in vitro and ex vivo to human colorectal carcinoma and to inhibit growth of human carcinomas grafted in nude mice was administered to 52 colorectal carcinoma patients and 15 patients with other types of cancer. Of 63 colorectal carcinoma tumor sites studied, 34 showed significant accumulation of antibody by external photoscanning and tomoscintigraphy, whereas none of the 20 sites of other cancer types gave positive results. One-third of the patients received F(ab')2 fragments of the MAb, which gave a slightly higher percentage (61%) of positive results than did intact MAbs (51%). A few patients scheduled for tumor resection were given injections simultaneously of 131I-labeled MAb and 125I-labeled normal immunoglobulin G. Antibody concentration in resected tumors was 3.6 to 6.3 times higher than the average antibody concentration in adjacent normal tissues (1.5, 3.4, and 9.4 as compared with normal mucosa, serosa, and fat, respectively), and the specificity indices, calculated by differential radioactivity analysis, ranged from 2.1 to 5.1. The results show the potential value and limitations of this particular MAb for tumor detection by immunoscintigraphy.

Positive anticalcitonin immunoscintigraphy in patients with medullary thyroid carcinoma.

A cocktail of three monoclonal F(ab')2 fragments against three distinct epitopes of calcitonin or PDN 21 was labelled with either 111In or 131I. These F(ab')2 fragments, a control 125I-F(ab')2 fragment and 99mTc-pertechnetate were injected into four patients suffering from medullary thyroid carcinoma. Scintigraphy data were processed by energy factor analysis for an optimal separation of images corresponding to each isotope. The best tumor detection was obtained 1-3 days after injection of the 111In-F(ab')2 cocktail which clearly labeled the thyroid tumors in the four patients (smallest tumor detected, 0.6 cm) as well as lymph node and bone metastases. In the liver, positive detection was only successful with the 131I-labeled cocktail. These results were confirmed by counting rates of resected specimens which provided average specificity indices ranging from 3.3 to 13.1. Anticalcitonin antibodies could be particularly useful for immunoscintigraphy detection of residual or recurrent medullary thyroid carcinoma in patients with elevated calcitonin serum level.

Octreotide scintigraphy in patients with differentiated thyroid carcinoma: contribution for patients with negative radioiodine scan.

Somatostatin receptor scintigraphy (SRS) was evaluated in 25 differentiated thyroid carcinoma (DTC) patients. All DTC patients had elevated thyroglobulin levels. A total body scan (TBS) was performed 4 and 24 h after injection of indium-111-DTPA-Phe-octreotide. Group 1 included 16 patients with negative 131I TBS; group 2 had 9 patients with positive 131I TBS. SRS results were compared to the results of conventional imaging methods in group 1 and to 131I TBS in group 2. 131I TBS was performed after administration of a therapeutic dose of 131I in all patients except one. SRS was positive in 20 of 25 (80%) patients. In group 1, SRS was positive in 12 of 16 patients; in the 3 patients with no previously known tumor site, SRS visualized one abnormal neck focus of uptake in two. In the other 13 patients, SRS disclosed unknown mediastinal foci in 2, but visualized less organ involvements and a smaller number of tumor sites than conventional imaging methods. In group 2, SRS was positive in 8 of 9 patients and visualized an identical (7 patients) or a smaller number (1 patient) of involved organs than 131I TBS; in 2 patients, SRS allowed the discovery of 1 abdominal and 1 bone tumor site. We suggest than SRS should guide imaging modalities in DTC patients with negative 131I TBS and be an alternative to 131I TBS in DTC patients unable to withdraw T4 treatment.

Relationship between thyrotropin stimulation and radioiodine uptake in lung metastases of differentiated thyroid carcinoma.

To examine whether the injection of bovine TSH (bTSH) produces maximal radioactive iodine uptake (RAIU) in lung metastases in patients with differentiated thyroid cancer, 10 patients were studied 12 times. In 10 of these studies, an initial RAIU measurement was performed immediately after 3 injections of 10 IU bTSH given immediately after T3 withdrawal. Another RAIU measurement was performed 7-19 days after T3 withdrawal. Uptake increased in all patients even when it was clearly detectable immediately after bTSH stimulation. Thus, 3 days of bTSH stimulation in these patients did not lead to maximal 131I uptake, and it could only be reached after prolonged endogenous TSH stimulation. bTSH was not injected in the 2 other patients, in whom 6 RAIU measurements were carried out. Radioiodine uptake increased with time in both patients. It appears that both the level of endogenous TSH and the length of stimulation play a determining role in RAIU. This might explain why 3 days of bTSH stimulation are insufficient to elicit maximal 131I uptake.

Use of m-[131I]iodobenzylguanidine in the treatment of malignant pheochromocytoma.

The efficacy and safety of m-[131I]iodobenzylguanidine ([131I]MIBG) were assessed in 15 patients with malignant pheochromocytomas in a nonrandomized, single arm trial, in which patients were treated with [131I]MIBG (SA, 740 megabequerel/mg) every 3 months. Seven of these patients had bone and soft tissue metastases, 4 had only soft metastases, and 4 had only bone metastases. The follow-up period ranged from 6-54 months; the number of doses ranged from 2-11, with 2.9 (78.4 mCi) to 9.25 gigabequerel (GBq) (250 mCi)/administration and a cumulative activity from 11.1-85.90 GBq (300-2322 mCi). The absorbed cumulative dose in tumors ranged from 12-155 Gy. A beneficial effect of the treatment was observed in 9 patients (60%). No complete remission of the disease was observed. Seven patients died during the study, among whom 4 never responded to the treatment. Seven had hormonal responses (4 complete and 3 partial), with a duration ranging from 5-48 months. Among these patients, 4 relapsed, and 3 died within 3 months. Five patients had partial tumoral responses mainly located in soft tissues and for a duration ranging from 29-54 months. All patients with a hormonal response had objective improvement in clinical status and blood pressure. There was no clear-cut relationship between the cumulative dose and the responses. The main side-effect observed in 1 patient with widespread bone metastases after three doses (12.9 GBq) was a pancytopenia, which resolved after treatment was discontinued. This study suggests that repeated [131I]MIBG treatment could be effective in patients with advanced malignant pheochromocytoma.

Long-term results of treatment of 283 patients with lung and bone metastases from differentiated thyroid carcinoma.

We assessed the results of treatment in 283 patients with lung or bone metastases from differentiated thyroid carcinoma who were followed for up to 40 yr (median, 44 months) after the discovery of the metastases. The survival rates from the time of discovery of the metastases were 53% at 5 yr, 38% at 10 yr, and 30% at 15 yr; 156 patients died. Multivariate analysis revealed that only 4 variables had an independent prognostic significance for survival. They were extensive metastases, older age at discovery of the metastases, absence of radioiodine uptake by the metastases, and moderately differentiated follicular cell type. The site of metastases (lung or bone) was not a prognostic factor for survival after treatment of metastatic disease. Remission was achieved in 79 patients after metastases were found. The only predictive factor for 5-yr disease-free survival after treatment of metastases was the initial extent of disease. Our results suggest that the aim of management should be to detect and treat metastases in patients with thyroid cancer as early as possible.

Prognostic factors in patients with liver metastases from colorectal carcinoma treated with discontinuous intra-arterial hepatic chemotherapy.

48 patients with colorectal cancer metastatic to the liver were implanted with a subcutaneous access system allowing hepatic intra-arterial perfusion. Regional chemotherapy used 5-fluorouracil, while 17 patients also received low-dose mitomycin at the beginning of the study. Responses to the treatment occurred in 29 patients (60%) and median survival was 14.4 months. Toxicity included gastroduodenal erosions in 12.5% of the patients, leucopenia in 20.8%, catheter thrombosis in 42% and arterial thrombosis in 50%. 2 patients died of digestive haemorrhage probably related to treatment. When individually analysed, four factors were found to significantly affect survival: presence of hepatomegaly (defined as palpable liver edge exceeding the right costal margin by more than 5 cm) (P = 0.006), percentage of hepatic replacement superior to 50% (P = 0.003), more than four metastases (P = 0.025) and hypovascularised metastases at radionuclide liver scan with 99m technetium-labelled macroaggregate albumin (MAA) (P = 0.04). The effect of the four variables on the observed survival time was analysed using a Cox regression model. Two variables were found to have simultaneously influenced survival. Presence of hepatomegaly emerged as the more significant (P = 0.0001), the other being hypovascularised metastases at 99mTc-MAA.

Phase I and pharmacological study of intra-arterial hepatic administration of pirarubicin in patients with advanced hepatic metastases.

Intra-arterial hepatic (i.a.h.) administration of the doxorubicin analogue pirarubicin was evaluated in a phase I trial, based on preclinical studies that showed an advantage of pirarubicin over doxorubicin after locoregional hepatic administration. Pirarubicin was given to 9 patients with metastatic liver disease with intrapatient dose escalation. Of the 58 cycles evaluable for tolerance, no hepatobiliary or vascular toxicity was observed. The dose-limiting toxicity was granulocytopenia: the maximum administered doses ranged from 50 to 120 mg/m2, suggesting variable rates of pirarubicin hepatic extraction between patients. Pharmacokinetic data obtained in 7 patients, in which a direct comparison of intravenous (i.v.) and i.a.h. administration was possible, indicated a median i.v./i.a.h. ratio of 7.4 for the maximal plasma concentration, and a median ratio of 4 for the area under the plasma concentrations versus time curves, suggesting a high pirarubicin hepatic extraction. An unexpectedly high response rate was observed: two complete (colorectal carcinoma) and two partial responses. These data demonstrate that i.a.h. pirarubicin not only produced high locoregional concentrations and reduced systemic exposure, but can also achieve responses in metastatic liver disease of colorectal origin.

Potential contribution of 131I-labelled monoclonal anti-CEA antibodies in the treatment of liver metastases from colorectal carcinomas: pretherapeutic study with dose recovery in resected tissues.

20 patients with liver metastases from colorectal carcinoma undergoing laparotomy received 15-60 mg intravenously, either intact or fragments of, anti-carcinoembryonic antigen (anti-CEA) monoclonal antibodies labelled with 0.55-1.48 GBq (15-40 mCi) of 131I, 3-8 days prior to operation. The uptake measured per gram of metastases ranged from 0.33 to 6.6 x 10(-3%) of injected dose. Tumour to liver uptake ratios ranged from 2 to 33. The radiation dose, estimated in 6 patients (3 of each group), for an extrapolated dose of 3.7 GBq (100 mCi) of 131I ranged from 0.3 to 0.8 Gy in normal liver or spleen (an acceptable estimate for bone marrow radiation dose) and from 3.4 to 8.2 Gy to the hepatic metastases, indicating that probably other therapeutic modalities should be associated with radioimmunotherapy.

Immunoscintigraphy of Hodgkin's disease: in vivo use of radiolabelled monoclonal antibodies derived from Hodgkin cell lines.

The Hodgkin associated monoclonal antibody (Mab) HRS-1 reacts with Hodgkin and Reed-Sternberg cells (HR-S) in all HD subtypes. HRS-1 Mab was labelled with radioiodine and injected into 10 patients for immunoscintigraphy (IS). Seven patients were injected with HRS-1 Mab radiolabelled with 131I and three patients were injected with HRS-1 Mab labelled with 123I. A control anti-alpha-fetoprotein (anti-AFP) Mab was radiolabelled with another iodine isotope and was injected simultaneously in five cases. Six out of eight patients with proven HD had a true positive scan (nodal, splenic and bony involvement). Imaging was equivocal or failed in the two other patients. In the last two patients IS imaging was truly negative due to the absence of residual HD in one patient and to an erroneous histological diagnosis of HD in another patient. These results, although preliminary, demonstrate that IS with radioiodine-labelled HRS-1 Mab is feasible and may prove to be informative in the staging of HD.

Refining interpretation of MIBG scans in children.

UNLABELLED: In pediatrics, the distribution of radioiodinated metaiodobenzylguanidine (MIBG) has been studied primarily in neuroblastoma. However, normal patterns in children show a number of particularities and pitfalls related to the context of pediatric oncology which must be identified. METHODS: We report on 28 equivocal scans in 24 children. In all cases, two experienced observers judged the scans to be equivocal and the definite interpretations were confirmed by follow-up. RESULTS: Difficulties in interpreting the scans were observed at the level of the thorax (15 patients), the abdomen (5 patients), the head (4 patients) or elsewhere (4 patients). The final interpretation of the scans was attributed to an unusual physiological pattern linked to age (9 patients), tumoral context (17 patients) or artifacts (2 patients). CONCLUSIONS: A number of important physiological areas of uptake in soft tissues can lead to false-positive interpretations of normal scans, such as the physiological upper thoracic uptake which has never been previously described. Numerous technical and physiological possibilities exist and those pitfalls must be ruled out. A precise knowledge of these technical difficulties and physiological variants can reduce the number of equivocal MIBG scans.

Indium-111-pentetreotide scintigraphy in children with neuroblast-derived tumors.

UNLABELLED: The somatostatin analog 111In-pentetreotide was evaluated in 11 children with sympathetic embryonic cell-derived tumors. METHODS: Six neuroblastomas, four ganglioneuroblastomas and one ganglioneuroma (benign) were imaged 4 and 24 hr after injection of 111In-pentetreotide (5 MBq/kg) and 24 hr after administration of 123I-metaiodobenzylguanidine (MIBG) (3.7 MBq/kg). RESULTS: Primary tumor was detected with both tracers in four of the five patients studied before surgery (one Stage III neuroblastoma, one Stage IV neuroblastoma, one Stage IVs neuroblastoma, one ganglioneuroblastoma), but the ganglioneuroma was not localized. Detection of bone marrow metastases was clearly better with 111In-pentetreotide in two patients, similar or slightly better with MIBG in six and (true) negative with both procedures in three. The positivity rate of 111In-pentetreotide for imaging of metastases was higher in undifferentiated malignant tumors (six neuroblastomas: two very positive, three positive, one true-negative) than in histologically well-differentiated tumors (four ganglioneuroblastomas: three weakly positive, one true-negative). All patients with positive 111In-pentetreotide imaging results had elevated urinary catecholamine levels, and the two most 111In-pentetreotide-positive metastases were found in neuroblastomas from children with an aneuploid primary tumor. The 111In-pentetreotide and MIBG results were only partly correlated with bone marrow status, as assessed by immunocytological and histological studies at the time of scanning. CONCLUSION: Abnormalities detected in 111In-pentetreotide uptake were slightly different from those seen with MIBG as a first-line routine method in neuroblast-derived tumors. However, some MIBG as a first-line routine method in neuroblast-derived tumors. However, some MIBG-negative tumor sites were detected by 111In-pentetreotide in patients with neuroblastomas. Thus, 111In-pentetreotide could provide novel information on the biology and prognosis of tumors whose clinical significance remains to be defined.