PET/CT imaging in neuroblastoma.

123Iodine-metaiodobenzylguanidine (123I-MIBG) scintigraphy is currently the tracer of choice for neuroblastoma (NB). It has high diagnostic accuracy and prognostic value for the assessment of patients after chemotherapy. A positive 123I-MIBG scan is also used for the basis of targeted radionuclide therapy with 131I-MIBG. I-123 MIBG scan however has some limitations which should be taken into account. Moreover the reasons for false negative MIBG results have not been entirely elucidated. Meticulous correlation with radiological examinations and recognition of the normal distribution pattern of 123I-MIBG in children is vital to obtain optimal results. With its technical superiorities, positron emission tomography/computed tomography (PET/CT) can be successfully introduced into the diagnostic workup of NB. Different PET tracers have been offered for imaging in patients with NB, and the efficacy of this modality has been compared with that of 123I-MIBG scan. Our review aims to analyze the present role of PET/CT imaging and radiopharmaceuticals in NB.

Role of low-cost thyroid follow-up in children treated with radiotherapy for primary tumors at high risk of developing a second thyroid tumor.

AIM: Differentiated thyroid cancer (DTC) is uncommon in childhood and data on its prevalence as a second malignant neoplasm (SNM) after radiotherapy (RT) for malignancies are limited. We evaluated: 1) the incidence DTC in pediatric-oncologic patients treated with RT; 2) the relationship between DTC, RT and the features of the first malignancy; 3) the usefulness of thyroid follow-up in irradiated oncological patients. METHODS: We have followed up 252 patients treated with RT out of 966 oncologic pediatric patients. Thyroid follow-up included TSH level evaluation and neck ultrasonography. In the presence of thyroid nodule/s ≥1 cm and/or with ultrasonography suspicious for malignancy, fine needle aspiration biopsy (FNAB) was performed. When papillary/follicular lesions were detected by cytology, thyroidectomy was performed. If DTC was confirmed, patients underwent radioactive iodine (RAI) treatment. RESULTS: At least one thyroid nodule was detected in 106 irradiated patients (42%): 45 patients underwent FNAB and 27 underwent thyroidectomy. Seventeen DTC (6.7%) were found on histology. A higher incidence of DTC was seen in patients with neuroblastoma (38%) or Wilms' tumor (18%). One third of DTC showed capsule invasion, and one fourth node involvement. Eleven patients, treated with a single RAI treatment, showed undetectable thyroglobulin levels after rh-TSH-stimulation. Five patients underwent at least two RAI treatments: four patients showed complete remission and one patient partial remission. CONCLUSION: A high rate of DTC, often with invasive features, was observed in children treated with RT for primary tumors. This finding underlines the usefulness of thorough low-cost thyroid follow-up in this high-risk population.

Could [18]F-fluorodeoxyglucose PET/CT change the therapeutic management of stage IV thyroid cancer with positive (131)I whole body scan?

AIM: Stage-IV differentiated thyroid cancer (DTC) patients may present elevated serum thyroglobulin (Tg) levels associated with positive [(131)I] whole-body-scan (WBS). Nevertheless some patients in whom WBS does not reveal new sites of disease show increased Tg levels. This finding prompts thorough restaging in order to exclude the presence of metastases unable to concentrate iodine. The aim of our study was to evaluate the impact of [(18)F]FDG-PET/CT in both the assessment of overall extent of the disease and the therapeutic management in a group of stage-IV DTC patients. METHODS: On suspicious of non-iodine concentrating additional metastases, 20 stage-IV DTC patients with increasing Tg levels and stable positive post-therapy WBS were enrolled. Conventional imaging (CI) procedures, including neck ultrasonography, bone-scintigraphy and computed tomography (CT) were performed before [(18)F]FDG-PET/CT. RESULTS: [(18)F]FDG-PET/CT was positive in 16 out of 20 patients (80%). In 9 patients (45%) [(18)F]FDG PET/CT detected a larger number of tumour recurrences/metastatic sites than WBS+CI. [(18)F]FDG PET/CT findings prompted modification of the management of 11 patients (55%), in whom surgery or external radiotherapy were eventually considered more appropriate than radioactive iodine therapy. These further therapies improved the quality of life in several patients but did not change their survival rate. CONCLUSION: Our results showed that [18F]FDG-PET/CT can detect new radioiodine-negative metastases in advanced DTC patients with unchanged positive WBS and increasing Tg levels. [(18)F]FDG-PET/CT may constitute a useful tool in the choice of the best therapeutic strategy in such difficult cases.

MCI patients declining and not-declining at mid-term follow-up: FDG-PET findings.

Patients with Mild Cognitive Impairment (MCI) not converted to dementia at one to three years follow-up represent a heterogeneous group across studies, by including 'late converters' but also patients without any neurodegenerative disease. We tested the hypothesis that the combination of memory and brain metabolic assessment could identify subgroups of memory decliners (MCI/Decl) and non-decliners (MCI/noDecl) before a long follow-up time is available. From twenty-nine patients with amnestic MCI (aMCI) at baseline, three groups were identified at follow-up: 10 patients who converted to AD (MCI/AD); 10 patients either showing episodic memory worsening or reaching the floor effect on memory and declining in other key tests (MCI/Decl) and 9 patients showing no memory worsening or even improvement (MCI/noDecl). They were compared with a group of fourteen elderly controls (CTR) by means of basal FDG-PET voxel-based analysis (SPM2). Two hypometabolic clusters were found in MCI/AD versus CTR, including the bilateral posterior cingulate cortex, the left parietal precuneus and the left fusiform gyrus. MCI/AD showed also a large hypometabolic region, mainly including the left medium and superior temporal gyri and inferior parietal lobule, when compared to MCI/noDecl. The MCI/Decl showed a hypometabolic region in the left medial temporal lobe versus both CTR (hippocampus) and MCI/noDecl (parahippocampal gyrus and hippocampus). No significant difference was found in the comparison between CTR and MCI/noDecl, neither in the comparison between MCI/Decl and MCI/AD. Thus, non converter MCI patients comprised a sub-group of 'decliners' with AD-like metabolic and cognitive patterns, likely including 'late converters', and a sub-group lacking this pattern, with stable or improving memory function and a brain metabolic picture similar to that in healthy controls. Combining neuropsychological and FDG-PET information could be used for prognostic purposes in aMCI patients at medium-term follow-up.

Low thyroglobulin concentrations after thyroidectomy increase the prognostic value of undetectable thyroglobulin levels on levo-thyroxine suppressive treatment in low-risk differentiated thyroid cancer.

DESIGN: Recombinant human TSH-stimulated thyroglobulin (Tg) levels (rhTSH-Tg) are sufficient for early follow-up of low-risk differentiated thyroid cancer (DTC) patients after thyroidectomy and radioiodine (131I) remnant ablation (RAI). Serum Tg levels at the time of remnant ablation (ablation-Tg) is thought to be related with rhTSH-Tg and may be predictive of recurrent disease. During long-term follow-up, Tg levels on levo-T4 (L-T4) suppressive treatment (suppressive-Tg) is sufficiently sensitive to avoid further evaluations in patients with undetectable rhTSH-Tg. The aim of our study was to verify whether, in a subgroup of low-risk DTC patients, the association of low ablation-Tg levels (<10 microg/l) with undetectable suppressive-Tg concentrations has a sufficient negative predictive value (NPV) for recurrence of disease, leading to avoid rhTSH testing. METHODS: We enrolled 169 low-risk DTC patients treated by thyroidectomy + RAI and undetectable suppressive-Tg at 12-month followup. In all patients, we retrospectively evaluated ablation-Tg and rhTSH-Tg. For all patients, 2-yr follow-up was available. RESULTS: Based on rhTSH-Tg>2 microg/l, relapsing disease was histologically proven in 2 patients. rhTSH-Tg levels between 0.6-2.0 microg/l, with no evidence of disease, was observed in 10 patients (6%). One hundred and fifty-seven patients showed undetectable rhTSH-Tg. The NPV of undetectable suppressive- Tg was 92.8%. The ablation-Tg level was <10 microg/l in 140 patients. In this group, the NPV of undetectable suppressive- Tg was 100%. CONCLUSION: Our data indicate that undetectable suppressive-Tg value, combined with ablation- Tg levels <10 microg/l, may avoid a significant number of high-cost rhTSH-Tg test.

Megatherapy combining I(131) metaiodobenzylguanidine and high-dose chemotherapy with haematopoietic progenitor cell rescue for neuroblastoma.

Despite the use of aggressive chemotherapy, stage 4 high risk neuroblastoma still has very poor prognosis which is estimated at 25%. Metabolic radiotherapy with I(131) MIBG appears a feasible option to enhance the effects of chemotherapy. Seventeen patients having MIBG-positive residual disease received 4.1-11.1 mCi/kg of I(131) MIBG 7-10 days before initiating the high-dose chemotherapy cycle consisting of busulphan 16 mg/kg and melphalan 140 mg/m(2) followed by PBSC infusion. We compared the toxicity in these patients to that seen in 15 control subjects with neuroblastoma who underwent a PBSC transplant without MIBG therapy. We observed greater toxic involvement of the gastrointestinal system in children treated with I(131) MIBG: grade 2 or 3 mucositis developed in 13/17 patients treated with I(131) MIBG and in 9/15 treated without it. Grade 1-2 gastrointestinal toxicity occurred in 12/17 children given MIBG and in 5/15 of the controls. One child receiving I(131) MIBG developed transient interstitial pneumonia. Another child who also received I(131) MIBG after PBSC rescue developed fatal pneumonia after the third course of metabolic radiotherapy. Our experience indicates that MIBG can be included in the high-dose chemotherapy regimens followed by PBSC rescue for children with residual neuroblastoma taking up MIBG. Attention should be paid to avoiding lung complications. Prospective studies are needed to demonstrate the real efficacy of this treatment.

131I-metaiodobenzylguanidine (131I-MIBG) therapy for residual neuroblastoma: a mono-institutional experience with 43 patients.

Incomplete response to therapy may compromise the outcome of children with advanced neuroblastoma. In an attempt to improve tumour response we incorporated 131I-metaiodobenzylguanidine (131I-MIBG) in the treatment regimens of selected stage 3 and stage 4 patients. Between 1986 and 1997, 43 neuroblastoma patients older than 1 year at diagnosis, 13 with stage 3 (group A) and 30 with stage 4 disease (group B) who had completed the first-line protocol without achieving complete response entered in this study. 131I-MIBG dose/course ranged from 2.5 to 5.5 Gbq (median, 3.7). The number of courses ranged from 1 to 5 (median 3) depending on the tumour response and toxicity. The most common acute side-effect was thrombocytopenia. Later side-effects included severe interstitial pneumonia in one patient, acute myeloid leukaemia in two, reduced thyroid reserve in 21. Complete response was documented in one stage 4 patient, partial response in 12 (two stage 3, 10 stage 4), mixed or no response in 25 (ten stage 3, 15 stage 4) and disease progression in five (one stage 3, four stage 4) Twenty-four patients (12/13 stage 3, 12/30 stage 4) are alive at 22-153 months (median, 59) from diagnosis. 131I-MIBG therapy may increase the cure rate of stage 3 and improve the response of stage 4 neuroblastoma patients with residual disease after first-line therapy. A larger number of patients should be treated to confirm these results but logistic problems hamper prospective and coordinated studies. Long-term toxicity can be severe.

99mTc-white cell scanning to detect gut inflammation in children with inflammatory bowel diseases or spondyloarthropathies.

OBJECTIVE: Gut inflammation is a common feature shared by inflammatory bowel diseases (IBD) and the spondyloarthropathies (SpA). The aim of the present study was to compare the reliability of a number of non-invasive investigations for the detection of an inflammatory process of the intestine. METHODS: Forty-two children were studied: (i) patients with a previous diagnosis of IBD (group A); (ii) patients with suspected IBD (group B); and (iii) patients with predominantly rheumatological manifestations associated with gastrointestinal symptoms (group C). All the patients were studied using 99mTechnetium-HMPAO labelled white cell scanning (99mTc-WCS), and abdominal ultrasound (US). In addition the ESR, serum class A immunoglobulins, faecal occult blood (OB) and faecal alpha 1-antitripsin level (F alpha 1-AT) were determined. Colonoscopy plus multiple biopsies and radiological study of the intestine were used as gold standards. RESULTS: 99mTc-WCS showed the highest sensitivity (85%) and specificity (100%) in detecting the presence of gut inflammation. This was followed by ESR and faecal occult blood (63% sensitivity, 44% specificity), F alpha 1-AT (43% sensitivity, 44% specificity) and IgA (42% sensitivity, 88% specificity). Ultrasound was informative in 28% of the active/affected patients, with a specificity of 75%. CONCLUSION: Although ileo-pancolonscopy remains the gold standard for the histological characterisation of gut inflammation, 99mTc-WCS represents the most reliable non-invasive test for its detection.

Radioiodinated meta-iodobenzylguanidine in the diagnosis of childhood neuroblastoma.

In a group of 97 patients aged from 6 months to 12 years, all with suspected or proven neural crest tumours, metaiodobenzylguanidine (MIBG) scintigraphy was performed at the time of diagnosis and, in some instances, after induction chemotherapy. All the patients underwent a tumour biopsy with cytological and histological analysis, in addition to imaging examinations such as X-rays, ultrasound, computed tomography and magnetic resonance, within a short period before or after scintigraphy. In 82 of 97 cases MIBG was effective in detecting the primary tumour, hence the technique's sensitivity was 84%. A significant different of sensitivity between [131I]MIBG and [123I]MIBG was not demonstrated. As regards metastatic locations, MIBG scans revealed one or more bone metastases in 12 cases, bone marrow involvement (assumed to be present when diffuse and symmetric uptake in the spine, pelvis and possibly other skeletal sites were visualized) in 9 cases, and focal liver metastases or hepatomegaly in 4 cases. Probably owing to the restrictive diagnostic criterion adopted or to the early phase of the bone marrow involvement, the last was found by biopsy but missed by MIBG in 25 cases. The overall sensitivity in detecting metastases was low (48%), but it was much higher if only bone metastases were considered (81%). Twenty-nine patients who had positive scans at diagnosis were checked following 1-2 courses of induction chemotherapy (IC). MIBG scans remained positive in 22 primary tumours, while 7 primary masses were no longer detected. Out of 12 cases showing metastases at diagnosis, two cases with liver lesions became normal and in one case some, but not all, of the bone lesions were not detectable; 4 cases remained abnormal, while in 5 cases bone marrow involvement was not confirmed. Three cases were confirmed to be true negatives; in 4 other cases bone marrow involved not showing at diagnosis was revealed and confirmed by biopsy; 3 cases in which bone marrow involvement was not revealed by MIBG at diagnosis, had normal MIBG and biopsy results after IC; finally, 2 false negative bone marrow cases and 5 true negative cases at diagnosis remained unchanged, but were not checked by biopsy. Performing total body MIBG scintigraphy in childhood neuroblastoma at diagnosis is useful: 1) to predict the nature of the masses detected by other imaging techniques, when biopsy has not yet been performed; 2) for more accurate tumour staging, in addition to standard imaging investigations, MDP scintigraphy and bone marrow aspiration biopsy, thanks to its ability to detect metastatic lesions; 3) to anticipate the decrease in sensitivity of the technique in detecting both the primary mass and the metastases following induction chemotherapy.

Place of meta-[131I]iodobenzylguanidine in the treatment of neuroblastoma: the Genoa experience.

The aim of this paper is to focus on our previous experience with the treatment of Group 3 and 4 neuroblastoma patients and on the therapeutic use of [131I]MIBG, to better define the role of this radioactive drug in the treatment of neuroblastoma (NB). Analysis of the studies on Group 3 patients treated with chemotherapy and surgery showed that the progression-free survival (PFS) increased from 45% for patients treated before 1985 to 63% for patients treated in the period of 1985-1989 and to 78% for patients treated after 1989. [131I]MIBG administered in 17 Group 3 patients who did not achieve a radical excision of the primary resulted in 7 partial response (PR) and 5 minor response (MR), with 10 cases of long term survival. Results in Group 4 patients confirmed the good prognosis in the subset of children aged 6-12 months at diagnosis (PFS 86% at 5 years). In patients aged > 12 months at diagnosis intensive induction chemotherapy induced a higher response rate of 69% and PFS was 26% at 5 years. [131I]MIBG administered in advanced stage 4 patients induced a response in 50% of the cases (2 complete response [CR], 13 PR and 2 MR out of 34 children) and 8 children treated for residual primary (4 cases) or residual bone metastases (4 cases) are long term survivors. We conclude that [131I]MIBG is the treatment of choice in Group 3 patient with a residual primary tumor and could contribute to consolidate the response obtained in Group 4 patients.

Predicting severe ischemic events after uncomplicated myocardial infarction by exercise testing and rest and exercise radionuclide ventriculography.

BACKGROUND: In 183 patients with uncomplicated myocardial infarction, exercise-induced angina, ST segment depression, decrease in ejection fraction, or inadequate increase in systolic blood pressure and low exercise tolerance were significantly associated with 4-year incidence of hard ischemic events. METHODS AND RESULTS: Only the onset of both ST segment depression and a decrease in left ventricular ejection fraction with exercise was an independent predictor. ST segment depression and decrease in left ventricular ejection fraction had low sensitivity (61% and 70%) and specificity (56% and 51%) for hard ischemic events, but specificity increased to 78% when both were present. During medical therapy, 22 of 53 patients with both ST segment depression and a decrease in left ventricular ejection fraction with exercise had an ischemic event (i.e., 48.1% 4-year probability on Kaplan-Meier analysis vs 19.2% in the remaining 130 patients [p < 0.0005]). CONCLUSIONS: Even if no single variable, derived from exercise testing, is a highly sensitive and specific predictor, specificity increases to a clinically relevant level by combining ST segment depression and a decrease in left ventricular ejection fraction with exercise, and in this way patients with recent infarction may be selected for coronary arteriography.

Semiquantitative evaluation of regional cerebral flow by means of SPECT with 99mTc-hexamethyl-propylene amine oxime in hypertensive patients under treatment.

Cerebral SPECT with 99mTc-HM-PAO allows a semiquantitative evaluation of regional cerebral blood flow (rCBF). Using this method we studied 25 patients affected by slight-to-moderate degree hypertension, in effective pharmacological treatment, and a control group of normotensives. On the cross-sections symmetrical ROIs were traced at the level of the cerebral lobes and the cerebellum. From the counts obtained on the ROIs the rCBF values were calculated in percentage units with Lassen's algorithm. We found no significant differences between the rCBF values of the two groups. In 5 hypertensive patients, however, focal areas of hypoperfusion were evidenced. These patients did not differ from the other hypertensives by pressure levels or other risk factors. Neurological, tomographic and flowmeter examinations of the supraaortic arteries proved to be normal. It is possible that SPECT with 99mTc-HM-PAO identifies a subgroup of hypertensives at risk of future cerebrovascular pathology despite the setting up of an effective antihypertensive therapy.

[131I]metaiodobenzylguanidine therapy in advanced neuroblastoma.

Forty-two children with advanced neuroblastoma who either failed with first-line therapy or relapsed after achieving a complete remission, were considered for treatment with [131I]metaiodobenzylguanidine (131I-MIBG). We subdivided 42 cases into 5 groups, in accordance with the stage of disease at diagnosis, response to first-line therapy and relapse. A total of 99 courses of 131I-MIBG were administered with doses ranging from 2.8 to 6.0 GBq. One child received six courses, 3 four courses, 18 three courses, 6 two courses and 15 one course of 131I-MIBG. The total delivered dose in single measurable lesions ranged from 286 to 1691 cGy with an uptake factor ranging from 3% to 10%. We obtained a major response in primary tumors, and a long-term response was observed in 5 cases, lasting more than 2 years without further chemotherapy.

[Functional evaluation of gastric and jejunal transplant after esophagectomy]. / Valutazione funzionale dell'impianto gastrico e digiunale dopo esofagectomia.

Increased survival rates after esophagectomy for cancer and the significant development of forms of therapy alternate to surgical treatment, today compel surgeons to devote far more attention to the methods will pursue in reconstructing the alimentary tract after removal of the esophagus. Nine patients with esophago-gastro-plasty and 6 with esophago-jejuno-plasty, after esophagectomy for cancer, experienced a study of esophageal function. The study consisted of extended esophago-gastro-intestinal manometry, performed both while at digestive rest after a semi-solid meal, and of scintigraphy, performed to investigate gastric emptying. 24-hours esophago-gastric pH-metry was also executed, along with basal and stimulated acidity metering in, patients with gastroplasty. The fundamental alterations, from the manometric point of view in esophago-gastro-plasty, are the absence of phase III of the IMMC interdigestively and in the absence of a motor response when ingesting the meal. Scintigraphically this coincides with a fundamental alteration of gastric tubule emptying. On the contrary, in jejunoplasty the jejunal loop retains adequate motility, both during the interdigestive phase and following a meal. Such strikingly diverse motor behavior explains the higher quality of life of patients with jejunoplasty versus patients in whom the stomach is used to substitute for the esophagus.

Treatment of advanced neuroblastoma with I-131 meta-iodobenzylguanidine.

From February 1986 to December 1988, 31 children with advanced pretreated neuroblastoma were treated with 131-I meta-Iodobenzylguanidine (131-MIBG). Thirteen children had been resistant to first-line therapy, three had suffered a local relapse, and fourteen had suffered a disseminated relapse without over bone marrow infiltration. One child was treated initially because of resistance to first-line therapy, and subsequently for a local relapse. A total of 72 courses of 131-MIBG was administered, with doses ranging from 2.8 to 6.0 GBq (median, 3.7 GBq). One child received five courses, two four courses, 13 three courses, four two courses, and 12 one course of 131-MIBG. The most common toxic effect was thrombocytopenia, with a platelet level of less than 50,000/cmm occurring after 19 of 60 evaluable courses. A leukocyte count less than 1000/cmm was seen only once. There were six major responses (two complete) lasting 4 to 9 months, and two minor responses lasting longer than 38 and 44 months. Responses were seen more commonly in children whose only lesion was a residual primary tumor and in children who had not been pretreated who experienced disseminated relapse. Further studies of the role of 131-I meta-Iodobenzylguanidine in treatment of neuroblastoma are needed.