Post-surgical thyroid ablation with low or high radioiodine activities results in similar outcomes in intermediate risk differentiated thyroid cancer patients.

BACKGROUND: In differentiated thyroid cancer (DTC) patients at intermediate risk of recurrences, no evidences are provided regarding the optimal radioactive iodine (RAI) activity to be administered for post-surgical thyroid ablation. METHODS: This study aimed to evaluate the impact of RAI activities on the outcome of 225 DTC patients classified as intermediate risk, treated with low (1110-1850  MBq) or high RAI activities (≥3700  MBq). RESULTS: Six to 18 months after ablation, remission was observed in 60.0% of patients treated with low and in 60.0% of those treated with high RAI activities, biochemical disease was found in 18.8% of patients treated with low and in 14.3% of patients treated with high RAI activities, metastatic disease was found in 21.2% of patients treated with low and in 25.7% of patients treated with high RAI activities (P=0.56). At the last follow-up (low activities, median 4.2 years; high activities, median 6.9 years), remission was observed in 76.5% of patients treated with low and in 72.1% of patients treated with high RAI activities, persistent disease was observed in 18.8% of patients treated with low and in 23.5% of patients treated with high RAI activities, recurrent disease was 2.4% in patients treated with low and 2.1% in patients treated with high RAI activities, deaths occurred in 2.4% of patients treated with low and in 2.1% of patients treated with high RAI activities (P=0.87). CONCLUSION: Our study provides the first evidence that in DTC patients at intermediate risk, high RAI activities at ablation have no major advantage over low activities.

Lack of association between urinary iodine excretion and successful thyroid ablation in thyroid cancer patients.

BACKGROUND: Low-iodine diet is prescribed before (131)I administration in patients with differentiated thyroid cancer, although no study has properly quantified its clinical benefit. OBJECTIVE: Our study aimed to evaluate the association between urinary iodine excretion (UIE) and (131)I ablation by correlating UIE with the rate of successful ablation. PATIENTS: We retrospectively studied 201 differentiated thyroid cancer patients who had received (131)I therapy and posttherapy whole-body scan (WBS) for remnant ablation after either thyroid hormone withdrawal (THW group, n = 125) or recombinant human TSH (rhTSH group, n = 76). The outcome of thyroid ablation was assessed using two different criteria: no visible uptake at control WBS 8-12 months after ablation or no visible uptake plus undetectable stimulated serum thyroglobulin (Tg). RESULTS: According to the criterion of no visible uptake, 84.6% of the patients were successfully ablated, with no significant difference between THW and rhTSH groups. Mean UIE at the time of ablation was 132 +/- 160 microg/liter, not significantly different between patients of the THW and rhTSH groups. There was no significant difference in UIE between ablated or nonablated patients both in the whole group and the rhTSH or THW groups. According to the criterion of no visible uptake plus undetectable stimulated serum Tg (in anti-Tg negative patients) at control WBS 8-12 months after ablation, UIE was not significantly different in ablated and nonablated patients. CONCLUSIONS: Our study indicates that the body iodine content is not an important determinant of thyroid ablation, when preparing the patients with either THW or rhTSH.

A comparison of 1850 (50 mCi) and 3700 MBq (100 mCi) 131-iodine administered doses for recombinant thyrotropin-stimulated postoperative thyroid remnant ablation in differentiated thyroid cancer.

OBJECTIVE: Recently, a multicenter study in differentiated thyroid cancer (DTC) patients showed that 3700 MBq 131-iodine ((131)I) after recombinant human TSH (rhTSH) had a successful thyroid ablation rate similar to that obtained after thyroid hormone withdrawal. We investigated whether 1850 MBq (131)I had a similar successful rate to 3700 MBq in patients prepared with rhTSH. DESIGN: A total of 72 patients with DTC were randomly assigned to receive 1850 (group A, n = 36) or 3700 MBq (group B, n = 36) (131)I after rhTSH. One injection of 0.9 mg rhTSH was administered for 2 consecutive days; (131)I therapy was delivered 24 h after the last injection, followed by a posttherapy whole-body scan. Successful ablation was assessed 6-8 months later. RESULTS: Successful ablation (no visible uptake in the diagnostic whole-body scan after rhTSH stimulation) was achieved in 88.9% of group A and B patients. Basal and rhTSH-stimulated serum thyroglobulin was undetectable (<1 ng/ml) in 78.9% of group A and 66.6% of group B patients (P = 0.46). Similar rates of ablation were obtained in both groups also in patients with node metastases. CONCLUSION: Therapeutic (131)I activities of 1850 MBq are equally effective as 3700 MBq for thyroid ablation in DTC patients prepared with rhTSH, even in the presence of node metastases.

Technetium-99m sestamibi scintigraphy is sensitive and specific for the staging and the follow-up of patients with multiple myeloma: a multicentre study on 397 scans.

We evaluated the additional benefit of Technetium(99)-sestamibi (99mTc-MIBI) scanning in comparison with standard X-ray techniques for multiple myeloma patients either at diagnosis or during follow-up. Between February 2001 and January 2005, 397 whole body scans were acquired. On 229 scans performed at diagnosis, 146 (64%) were positive and 81 cases have discordant X-ray results. The sensitivity of 99mTc-MIBI and X-ray were 77% and 45% respectively. As a result of 99mTc-MIBI, 40% of asymptomatic myeloma patients were up-staged. The positivity of 99mTc-MIBI correlated significantly with all of the most relevant clinical and biological parameters. Multivariate analysis selected only high reactive C protein (P = 0.0005), bone marrow infiltration (P = 0.02) and bone pain (P = 0.002) as factors affecting 99mTc-MIBI pattern. In 22 patients with solitary myeloma, 99mTc-MIBI was positive in 86% of cases and detected more disease sites than X-ray. Among 168 scans performed during follow-up, 99mTc-MIBI presented high specificity in patients showing a complete response (CR; 86%), and correlated with myeloma activity and with response to therapy. At multivariate analysis, a positive pattern correlated with bone marrow infiltration (P = 0.002) and disease status other than CR (P = 0.03). We conclude that 99mTc-MIBI scanning is an additional diagnostic tool with a high specificity for the staging and the follow-up of multiple myeloma patients.

Radiotherapy planning: PET/CT scanner performances in the definition of gross tumour volume and clinical target volume.

PURPOSE: Positron emission tomography is the most advanced scintigraphic imaging technology and can be employed in the planning of radiation therapy (RT). The aim of this study was to evaluate the possible role of fused images (anatomical CT and functional FDG-PET), acquired with a dedicated PET/CT scanner, in delineating gross tumour volume (GTV) and clinical target volume (CTV) in selected patients and thus in facilitating RT planning. METHODS: Twenty-eight patients were examined, 24 with lung cancer (17 non-small cell and seven small cell) and four with non-Hodgkin's lymphoma in the head and neck region. All patients underwent a whole-body PET scan after a CT scan. The CT images provided morphological volumetric information, and in a second step, the corresponding PET images were overlaid to define the effective target volume. The images were exported off-line via an internal network to an RT simulator. RESULTS: Three patient were excluded from the study owing to change in the disease stage subsequent to the PET/CT study. Among the remaining 25 patients, PET significantly altered the GTV or CTV in 11 (44%) . In five of these 11 cases there was a reduction in GTV or CTV, while in six there was an increase in GTV or CTV. CONCLUSION: FDG-PET is a highly sensitive imaging modality that offers better visualisation of local and locoregional tumour extension. This study confirmed that co-registration of CT data and FDG-PET images may lead to significant modifications of RT planning and patient management.