Slimane Zerdoud

Coregistration of prechemotherapy PET-CT for planning pediatric Hodgkin's disease radiotherapy significantly diminishes interobserver variability of clinical target volume definition.

PURPOSE To assess the interobserver variability in clinical target volume (CTV) definitions when using registered (18)F-labeled deoxyglucose positron emission tomography (FDG-PET-CT) versus side-by-side image sets in pediatric Hodgkins disease (HD). METHODS AND MATERIALS Prechemotherapy FDG-PET-CT scans performed in the treatment position were acquired from 20 children (median age, 14 years old) with HD (stages 2A to 4B) and registered with postchemotherapy planning CT scans. The patients had a median age of 14 years and stages of disease ranging between 2A and 4B. Image sets were coregistered using a semiautomatic coregistration system. The biological target volume was defined on all the coregistered images as a guide to defining the initial site of involvement and to avoid false-positive or negative results. Five radiation oncologists independently defined the CTV for all 20 patients: once using separate FDG-PET-CT images as a guide (not registered) to define CTVa and once using the registered FDG-PET-CT data to define CTVb. The total volumes were compared, as well as their coefficients of variation (COV). To assess the interobserver variability, the percentages of intersection between contours drawn by all observers for each patient were calculated for CTVa and for CTVb. RESULTS The registration of a prechemotherapy FDG-PET-CT scan caused a change in the CTV for all patients. Comparing CTVa with CTVb showed that the mean CTVb increased in 14 patients (range, 0.61%-101.96%) and decreased in 6 patients (range, 2.97%-37.26%). The COV for CTVb significantly decreased for each patient; the mean COVs for CTVa and CTVb were 45% (21%-65%) and 32% (13%-57%), respectively (p = 0.0004). The percentage of intersection among all CTVbs for the five observers increased significantly by 89.77% (1.99%-256.41%) compared to that of CTVa (p = 0.0001). CONCLUSIONS High observer variability can occur during CT-based definition of CTVs for children diagnosed with HD. Registration of FDG-PET and planning CT images resulted in significantly greater consistency of tumor volume definition.

The retrospective binning method improves the consistency of phase binning in respiratory-gated PET/CT

This study assesses the accuracy of prospective phase-gated PET/CT data binning and presents a retrospective data binning method that improves image quality and consistency. Respiratory signals from 17 patients who underwent 4D PET/CT were analysed to evaluate the reproducibility of temporal triggers used for the standard phase-based gating method. Breathing signals were reprocessed to implement retrospective PET data binning. The mean and standard deviation of time lags between automatic triggers provided by the Real-time Position Management (RPM, Varian) gating device and inhalation peaks derived from respiratory curves were computed for each patient. The total number of respiratory cycles available for 4D PET/CT according to the binning mode (prospective versus retrospective) was compared. The maximum standardized uptake value (SUV(max)), biological tumour volume (BTV) and tumour trajectory measures were determined from the PET/CT images of five patients. Compared to retrospective binning (RB), prospective gating approach led to (i) a significant loss in breathing cycles (15%) and (ii) the inconsistency of data binning due to temporal dispersion of triggers (average 396 ms). Consequently, tumour characterization could be impacted. In retrospective mode, SUV(max) was up to 27% higher, where no significant difference appeared in BTV. In addition, prospective mode gave an inconsistent spatial location of the tumour throughout the bins. Improved consistency with breathing patterns and greater motion amplitude of the tumour centroid were observed with retrospective mode. The detection of the tumour motion and trajectory was improved also for small temporal dispersion of triggers. This study shows that the binning mode could have a significant impact on 4D PET images. The consistency of triggers with breathing signals should be checked before clinical use of gated PET/CT images, and our RB method improves 4D PET/CT image quantification.

Quality of Life and Cost-Effectiveness Assessment of Radioiodine Ablation Strategies in Patients With Thyroid Cancer: Results From the Randomized Phase III ESTIMABL Trial

PURPOSE In the ESTIMABL phase III trial, the thyroid ablation rate was equivalent for the two thyroid-stimulating hormone (TSH) stimulation methods (thyroid hormone withdrawal [THW] and recombinant human TSH [rhTSH]) and the two iodine-131 ((131)I) activities (1.1 or 3.7 GBq). The objectives of this article were to present health-related quality-of-life (HRQoL) results and a cost-effectiveness evaluation performed alongside this trial. PATIENTS AND METHODS HRQoL and utility were longitudinally assessed, from random assignment to the follow-up visit at 8 ± 2 months for the 752 patients with thyroid cancer, using the Short Form-36 and the EuroQoL-5D questionnaires, respectively. A cost-effectiveness analysis was performed from the societal perspective in the French context. Resource use (hospitalization for (131)I administration, rhTSH, sick leaves, and transportation) was collected prospectively. We used the net monetary benefit approach and computed cost-effectiveness acceptability curves for both TSH stimulation methods and (131)I activities. Sensitivity analyses of the costs of rhTSH were performed. RESULTS At (131)I administration, THW caused a clinically significant deterioration of HRQoL, whereas HRQoL remained stable with rhTSH. This deterioration was transient with no difference 3 months later. rhTSH was more effective than THW in terms of quality-adjusted life-years (QALYs; +0.013 QALY/patient) but more expensive (+€474/patient). The probability that rhTSH would be cost effective at a €50,000/QALY threshold was 47% in France. The use of 1.1 GBq of (131)I instead of 3.7 GBq reduced per-patient costs by €955 (US

Oncocytic Adenoma of Thyroid Incidentally Detected by 18F-Fluorocholine PET/CT

1,018) but with slightly decreased efficacy (-0.007 QALY/patient). CONCLUSION rhTSH avoids the transient THW-induced deterioration of HRQoL but is unlikely to be cost effective at its current price.

Outcome after ablation in patients with low-risk thyroid cancer (ESTIMABL1): 5-year follow-up results of a randomised, phase 3, equivalence trial

A 58-old-man underwent 18F-fluorocholine PET/CT for restaging of prostate cancer because of a rising level of prostate-specific antigen.18F-fluorocholine showed no significant tracer uptake at the site of the prostatectomy or the pelvic lymph nodes. Incidental high tracer uptake was observed in a 26 × 23 mm left thyroid nodule. A benign tumor of the thyroid (oncocytic adenoma of thyroid) was diagnosed after left loboisthmectomy.

18F-Fluorine-18-l-dihydroxyphenylalanine (18F-DOPA) positive isolated peritoneal carcinomatosis from a MENII-related medullary thyroid carcinoma. About an atypical metastatic site and utility of 18F-FDOPA

BACKGROUND In ESTIMABL1, a randomised phase 3 trial of radioactive iodine (131I) administration after complete surgical resection in patients with low-risk thyroid cancer, 92% of patients had complete thyroid ablation at 6-10 months, defined as a recombinant human thyroid-stimulating hormone (rhTSH)-stimulated serum thyroglobulin concentration of 1 ng/mL or less and normal findings on neck ultrasonography. Equivalence was shown between low-activity (1·1 GBq) and high-activity (3·7 GBq) radioactive iodine and also between the use of rhTSH injections and thyroid hormone withdrawal. Here, we report outcomes after 5 years of follow-up. METHODS This multicentre, randomised, open-label, equivalence trial was done at 24 centres in France. Between March 28, 2007, and Feb 25, 2010, we randomly assigned (1:1:1:1) adults with low-risk differentiated thyroid carcinoma who had undergone total thyroidectomy to one of four strategies, each combining one of two methods of thyrotropin stimulation (rhTSH or thyroid hormone withdrawal) and one of two radioactive iodine activities (1·1 GBq or 3·7 GBq). Randomisation was by computer-generated sequence, with variable block size. Follow-up consisted of a yearly serum thyroglobulin measurement on levothyroxine treatment. Measurement of rhTSH-stimulated thyroglobulin and neck ultrasonography were done at the discretion of the treating physician. No evidence of disease was defined as serum thyroglobulin of 1 ng/mL or less on levothyroxine treatment and normal results on neck ultrasonography, when performed. This study was registered with ClinicalTrials.gov, number NCT00435851. FINDINGS 726 patients (97% of the 752 patients originally randomised) were followed up. At a median follow-up since randomisation of 5·4 years (range 0·5-9·2), 715 (98%) had no evidence of disease. The other 11 had either structural disease (n=4), raised serum thyroglobulin concentration (n=5), or indeterminate findings on neck ultrasonography (n=2). At ablation, six of these patients had received 1·1 GBq radioactive iodine (five after rhTSH and one after withdrawal) and five had received 3·7 GBq (two after rhTSH and three after withdrawal). TSH-stimulated (either after rhTSH injections or thyroid hormone withdrawal according to the treatment group) thyroglobulin concentration measured at the time of ablation was prognostic for structural disease status at ablation, ablation status at 6-10 months, and the final outcome. INTERPRETATION Our findings suggest that disease recurrence was not related to the strategy used for ablation. These data validate the use of 1·1 GBq radioactive iodine after rhTSH for postoperative ablation in patients with low-risk thyroid cancer. FUNDING French National Cancer Institute (INCa), French Ministry of Health, and Sanofi Genzyme.

Comparison of an alternative and existing binning methods to reduce the acquisition duration of 4D PET/CT.

A patient, operated for a medullary thyroid carcinoma (MTC) with a positive RET mutation, showed several peritoneal nodes on a computed tomography (CT), with increased Thyrocalcitonine. A 18F‐Fluorine‐18‐l‐dihydroxyphenylalanine (18‐F‐FDOPA) positron emission tomography (PET/CT) showed isolated tracer uptake on the nodes. A biopsy confirmed that it was from the MTC, with the same RET mutation as in blood.

Clinical outcomes 1 year after empiric : real life experience and predictive factors of functional response131: real life experience and predictive factors of functional responsei therapy for hyperthyroid disorders: real life experience and predictive factors of functional response

PURPOSE Respiratory motion is a source of artifacts that reduce image quality in PET. Four dimensional (4D) PET/CT is one approach to overcome this problem. Existing techniques to limiting the effects of respiratory motions are based on prospective phase binning which requires a long acquisition duration (15-25 min). This time is uncomfortable for the patients and limits the clinical exploitation of 4D PET/CT. In this work, the authors evaluated an existing method and an alternative retrospective binning method to reduce the acquisition duration of 4D PET/CT. METHODS The authors studied an existing mixed-amplitude binning (MAB) method and an alternative binning method by mixed-phases (MPhB). Before implementing MPhB, they analyzed the regularity of the breathing patterns in patients. They studied the breathing signal drift and missing CT slices that could be challenging for implementing MAB. They compared the performance of MAB and MPhB with current binning methods to measure the maximum uptake, internal volume, and maximal range of tumor motion. RESULTS MPhB can be implemented depending on an optimal phase (in average, the exhalation peak phase -4.1% of the entire breathing cycle duration). Signal drift of patients was in average 35% relative to the breathing amplitude. Even after correcting this drift, MAB was feasible in 4D CT for only 64% of patients. No significant differences appeared between the different binning methods to measure the maximum uptake, internal volume, and maximal range of tumor motion. The authors also determined the inaccuracies of MAB and MPhB to measure the maximum amplitude of tumor motion with three bins (less than 3 mm for movement inferior to 12 mm, up to 6.4 mm for a 21 mm movement). CONCLUSIONS The authors proposed an alternative binning method by mixed-phase binning that halves the acquisition duration of 4D PET/CT. Mixed-amplitude binning was challenging because of signal drift and missing CT slices. They showed that more than three bins were necessary for a more accurate measurement of the maximum amplitude of the tumor motion. However, the current 4D-CT technology limits the increase of the number of bins in 4D PET/CT because of missing CT slices. One can reconstruct 4D PET images with more bins but without attenuation/scatter correction.

Development of Photoonycholysis with Vandetanib Therapy.

Radioiodine is a therapeutic option in Europe for Graves’ disease (GD) and toxic multinodular goiter (MNG). Purpose To compare empiric and calculated 131I activities using 2013 EANM recommendations. To look for predictive factors of therapeutic response to an empiric activity of 131I. To assess clinical situations favoring calculated treatment modalities. Patients and methods Prospective monocentric study of clinical outcomes at 1 year follow-up in 86 patients with GD and MNG who received empiric 131I therapeutic activities (348–939 MBq). Differences between empiric and calculated activities were confronted to clinical outcomes. Physicians were not aware of the calculated activity at the time of prescription. Results One year after treatment, 9% (5/57) of GD patients and 7% (2/29) of MNG patients were still in a hyperthyroid state. Thyroid volume was reduced by 67% for GD and by 50% for MNG. In GD, empiric 131I activities were higher than calculated ones (564±131 vs. 316±319 MBq, P<0.001) in 93% (53/57) of patients. Pretherapeutic thyroid volume (>26 ml for GD; >40 ml for MNG) was associated with persistent hyperthyroidism. Conclusion Empirically administered 131I for GD and MNG was associated with very high efficacy in thyroid function control and no side effects. Thyroid volume reduction did not preclude treatment efficacy. Activity calculation could be a useful method for treating patients with GD and thyroid volumes higher than 26 ml or patients with MNG and thyroid volumes higher than 40 ml. A selective approach based on pretherapeutic thyroid volume and radioiodine biokinetics might improve treatment success.

Local recurrence of pheochromocytoma in multiple endocrine neoplasia type 2A: a diagnostic and therapeutic challenge

Vandetanib therapy is a novel once-daily oral multitargeted tyrosine kinase inhibitor, which is currently used in advanced or metastatic medullary thyroid cancer. Skin toxicities are among the most prevalent adverse events reported with this targeted therapy (e.g. acne-like rash, hand-foot skin reaction, hair changes, and paronychia). In addition, photosensitivity reactions may affect more than one third of treated patients. We report here 2 patients developing photosensitivity reactions with vandetanib therapy, including photoonycholysis. Our patients presented a wide range of phototoxic reactions with exaggerated sunburn reactions solely located to photoexposed areas or hyperpigmentation with visible blue dots. More importantly, both patients concomitantly developed nail changes consistent with type 1 photoonycholysis, which had never been reported so far neither with vandetanib therapy nor with other anticancer-targeted therapies. In addition, histopathologic findings and reflectance confocal microscopy imaging performed in one patient suffering from photodistributed skin hyperpigmentation both strengthen the likelihood of a postinflammatory mechanism. Clinicians should be aware of these underestimated but very characteristic photoinduced adverse events, which can lead to treatment interruption and require very strict photoprotective measures in treated patients.