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. © 1999 Cancer Research Campaig

Divergent determinants of 18F-NaF uptake and visible calcium deposition in large arteries: relationship with Framingham risk score.

Abstract To compare regional vascular distribution and biological determinants of visible calcium load, as assessed by computed tomography, as well as of molecular calcium deposition as assessed by (18)F-NaF positron emission tomography. Eighty oncologic patients undergoing (18)F-NaF PET/CT scan were included in the study. Cardiovascular-risk stratification was performed according to a simplified version of the Framingham model [including age, diabetes, smoking, systolic blood pressure and body mass index (BMI)]. Arterial (18)F-NaF uptake was measured by drawing regions of interest comprising the arteries on each slice of the transaxial PET/CT and normalized to blood (18)F-NaF activity to obtain the arterial target-to-background ratio (TBR). The degree of arterial calcification (AC) was measured using a software program providing Agatston-like scores. Differences in mean values and regression analysis were tested. Predictors of AC and TBR were evaluated by univariate and multivariate analysis. p value of 0.05 was considered statistically significant. No correlation was documented between regional calcium load and regional TBR in any of the studied arterial segments. Visible calcium deposition was found to be dependent upon age while it was not influenced by all the remaining determinants of cardiovascular risk. By contrast, (18)F-NaF uptake was significantly correlated with all descriptors of cardiovascular risk, with the exception of BMI. Vascular (18)F-NaF uptake displays a different regional distribution, as well as different biological predictors, when compared to macroscopic AC. The tight dependency of tracer retention upon ongoing biological determinants of vascular damage suggests that this tool might provide an unexplored window on plaque pathophysiology

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

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

Comparison of 18F-dopa PET/CT and 123I-MIBG scintigraphy in stage 3 and 4 neuroblastoma: a pilot study.

PURPOSE: (18)F-Dopa positron emission tomography (PET)/CT has proved a valuable tool for the assessment of neuroendocrine tumours. So far no data are available on (18)F-dopa utilization in neuroblastoma (NB). Our aim was to evaluate the role of (18)F-dopa PET/CT in NB and compare its diagnostic value with that of (123)I-metaiodobenzylguanidine (MIBG) scintigraphy in patients affected by stage 3-4 NB. METHODS: We prospectively evaluated 28 paired (123)I-MIBG and (18)F-dopa PET/CT scans in 19 patients: 4 at the time of the NB diagnosis and 15 when NB relapse was suspected. For both imaging modalities we performed a scan-based and a lesion-based analysis and calculated sensitivity, specificity and accuracy. The standard of reference was based on clinical, imaging and histological data. RESULTS: NB localizations were confirmed in 17 of 19 patients. (18)F-Dopa PET/CT and (123)I-MIBG scintigraphy properly detected disease in 16 (94%) and 11 (65%), respectively. On scan-based analysis, (18)F-dopa PET/CT showed a sensitivity and accuracy of 95 and 96%, respectively, while (123)I-MIBG scanning showed a sensitivity and accuracy of 68 and 64%, respectively (p < 0.05). No significant difference in terms of specificity was found. In 9 of 28 paired scans (32%) PET/CT results influenced the patient management. We identified 156 NB localizations, 141 of which were correctly detected by (18)F-dopa PET/CT and 88 by MIBG. On lesion-based analysis, (18)F-dopa PET/CT showed a sensitivity and accuracy of 90% whereas (123)I-MIBG scintigraphy showed a sensitivity and accuracy of 56 and 57%, respectively (p < 0.001). No significant difference in terms of specificity was found. CONCLUSION: In our NB population (18)F-dopa PET/CT displayed higher overall accuracy than (123)I-MIBG scintigraphy. Consequently, we suggest (18)F-dopa PET/CT as a new opportunity for NB assessment