Diego De Palma

Relationship between serum thyroglobulin and 18FDG-PET/CT in 131I-negative differentiated thyroid carcinomas.

The purpose of this study was to assess the relationship between [18F]‐fluorodeoxyglucose (18FDG)‐positron emission tomography/CT (18FDG‐PET/CT) and serum thyroglobulin (Tg) in patients with recurrent differentiated thyroid carcinoma (DTC).

Unstimulated high sensitive thyroglobulin measurement predicts outcome of differentiated thyroid carcinoma

Abstract Background: Thyroglobulin (Tg) measurement following thyrotropin (TSH) stimulation is used in the follow-up of patients with differentiated thyroid carcinoma (DTC). However, high-sensitive assays allow accurate measurement of serum Tg even without TSH stimulation. Here, we prospectively evaluated the impact of unstimulated high-sensitive Tg measurement in early and long-term outcome of patients with DTC. Methods: One hundred and ninety five patients affected with DTC were evaluated. Six months after thyroid ablation (i.e., thyroidectomy plus radioiodine) serum Tg was measured during TSH-suppressive thyroxine (T4) treatment (onT4-Tg). Patients with undetectable onT4-Tg and negative neck ultrasound (US) were considered disease free and onT4-Tg was measured every 12 months for a mean follow-up of 6.8 (4.7–8.9) years. Patients with an increase in onT4-Tg underwent specific diagnostic work-up and appropriate treatment if necessary. Results: Four patients showed recurrence at first follow-up visit with a corresponding increase in onT4-Tg concentrations (sensitivity 100%). Three patients had false positive onT4-Tg measurement (specificity 98%) with a spontaneous decrease within 3–6 months in all cases (specificity 100%). Three of 188 patients with undetectable serum onT4-Tg at first follow-up showed recurrence later with an increase in onT4-Tg as the first (n=2) or unique (n=1) sign of relapse (sensitivity 100%). Among 185 disease-free patients in a prolonged follow-up, 12 had a transient increase in onT4-Tg (specificity 91.6%). However, a spontaneous reduction within 3–6 months occurred in all cases (specificity 100%). Conclusions: Undetectable serum onT4-Tg using a high-sensitivity immunoradiometric assay 6 months after thyroid ablation predicts low-risk of DTC recurrence. When onT4-Tg became detectable during follow-up, the evaluation of Tg slope in a 3–6 months period accurately discriminated patients with DTC recurrence from those without recurrence. This helped avoid unnecessary diagnostic or therapeutic procedures. Clin Chem Lab Med 2009;47:1001–4.

Guidelines for lung scintigraphy in children

The purpose of this set of guidelines is to help the nuclear medicine practitioner perform a good quality lung isotope scan. The indications for the test are summarised. The different radiopharmaceuticals used for the ventilation and the perfusion studies, the technique for their administration, the dosimetry, the acquisition of the images, the processing and the display of the images are discussed in detail. The issue of whether a perfusion-only lung scan is sufficient or whether a full ventilation–perfusion study is necessary is also addressed. The document contains a comprehensive list of references and some web site addresses which may be of further assistance.

Guidance Document for Structured Reporting of Diuresis Renography

This Guidance Document for structured reporting of diuresis renography in adults was developed by the International Scientific Committee of Radionuclides in Nephro-urology (ISCORN; http://www.iscorn.org). ISCORN chose diuresis renography for its first structured report Guidance Document because suspected obstruction is the most common reason for referral, most radionuclide renal studies are conducted at institutions that perform fewer than 3 studies per week, and a large percentage of studies are interpreted by physicians with limited training in nuclear medicine. Ten panelists were asked to categorize specific reporting elements as essential, recommended, optional (without sufficient data to support a higher ranking), and unnecessary (does not contribute to scan interpretation or quality assurance). The final document was developed through an iterative series of comments and questionnaires with a majority vote required to place an element in a specific category. The Guidance Document recommends a reporting structure organized into indications, clinical history, study procedure, findings and impression and specifies the elements considered essential or recommended in each category. The Guidance Document is not intended to be restrictive but, rather, to provide a basic structure and rationale so that the diuresis renography report will: (1) communicate the results to the referring physician in a clear and concise manner designed to optimize patient care; (2) contain the essential elements required to evaluate and interpret the study; (3) clearly document the technical components of the study necessary for accountability, quality assurance and reimbursement; and (4) encourage clinical research by facilitating better comparison and extrapolation of results between institutions.

Guidelines for paediatric bone scanning with 99mTc-labelled radiopharmaceuticals and 18F-fluoride.

The purpose of these guidelines is to offer nuclear medicine teams a framework that could prove helpful in daily practice. The guidelines include information related to the indications, acquisition, processing and interpretation of bone scans in children, focusing primarily on 99mTc-labelled diphosphonate scintigraphy, and also recommendations with regard to the emerging use of PET with 18F-fluoride.

Inter-observer reproducibility in reporting on renal drainage in children with hydronephrosis: a large collaborative study

PurposeThe goal of this study was to evaluate the inter-observer reproducibility in reporting on renal drainage obtained during 99mTc MAG3 renography in children, when already processed data are offered to the observers.MethodsBecause web site facilities were used for communication, 57 observers from five continents participated in the study. Twenty-three renograms, including furosemide stimulation and posterect postmicturition views, covering various patterns of drainage, were submitted to the observers. Images, curves and quantitative parameters were provided. Good or almost good drainage, partial drainage and poor or no drainage were the three possible responses for each kidney.ResultsAn important bias was observed among the observers, some of them more systematically reporting the drainage as being good, while others had a general tendency to consider the drainage as poor. This resulted in rather poor inter-observer reproducibility, as for more than half of the kidneys, less than 80% of the observers agreed on one of the three responses. Analysis of the individual cases identified some obvious causes of discrepancy: the absence of a clear limit between partial and good or almost good drainage, the fact of including or neglecting the effect of micturition and change of patient’s position, the underestimation of drainage in the case of a flat renographic curve, and the difficulties of interpretation in the case of a small, not well functioning kidney.ConclusionThere is an urgent need for better standardisation in estimating the quality of drainage.

Different imaging strategies in febrile urinary tract infection in childhood. What, when, why?

Urinary tract infections (UTIs) are a common problem in childhood. During the last decade, published papers led to a deep revision in the use and usefulness of imaging tools in children with febrile UTIs. This new body of knowledge was partially endorsed by the guidelines published in 2007 by the UK’s National Institute for Clinical Excellence and in 2011 by the American Academy of Pediatrics. Nevertheless, new data continuously arise and the scientific debate always revives. Recommendations of published guidelines and strengths and weaknesses of the available biochemical and imaging tools are here critically analysed for giving to the reader a complete, up-to-date and flexible overview on this hot topic.

Interobserver reproducibility in reporting on renal cortical scintigraphy in children: A large collaborative study

ObjectiveTo evaluate the interobserver reproducibility in reporting on technetium-99m (99mTc) dimercaptosuccinic acid (DMSA) scan in children. MethodsSixty 99mTc-DMSA scans, issued from three centres, were distributed by e-mail to nuclear medicine physicians from the five continents interested in paediatric nuclear medicine. Observers had to choose, for each kidney, among four answers: normal, abnormal, equivocal or poor quality. An additional question was the location of the lesion if any: upper part, mid part, lower part. The responses had to be returned by e-mail. ResultsSixty-one observers, with an experience of approximately five or more 99mTc-DMSA/month, contributed to the study. Median agreement was 93%. The agreement was less than 80% in 29 kidneys (24%) but only in 13% (16 kidneys) was there disagreement between normality and abnormality, the remaining cases being related to ‘equivocal’ responses. Disagreement was mainly related to the following patterns: (i) normal variants: pear-shaped kidney, hypoactive poles contrasting with important parenchymal mass, triangular kidney, unusual shape of the columns of Bertin; (ii) congenital abnormalities: hydronephrosis, normal duplex kidney; (iii) small defects. ConclusionInterobserver reproducibility can be considered as good among a wide number of observers from the five continents. Disagreement among observers could be reduced by taking the normal variants into account.

PET/CT in paediatric oncology: clinical usefulness and dosimetric concerns

Childhood cancer, always particularly distressing, appears to be on the increase. The last quarter of the last century saw an approximately 25% rise in the incidence of diagnoses of malignancies (all forms) in children in the Western world (USA and Europe), the figure rising from around 12 per 100,000 in 1975 to 15 per 100,000 in 2,000. This corresponds to an average annual increase of approximately 1% for the whole period. Among the major types of childhood cancer, leukaemias and cancers of the central nervous system account for more than half of all new cases. Around a third of childhood cancers are leukaemias, the most common type being acute lymphoblastic leukaemia. The most common solid tumours in children are brain tumours (e.g. gliomas and medulloblastomas), while other solid cancers (e.g. neuroblastomas, Wilms tumours, and sarcomas such as rhabdomyosarcoma and osteosarcoma) are less common [2]. Due to significant advances in treatment, however, the same 25-year period also saw substantial improvements in survival, with 5-year survival rates for all childhood cancers (combined) rising from around 55–60% to around 75–80% percent, the average annual increase for the whole period being approximately 5%. Of course, the data vary around these values in relation to age, gender, geography and type of cancer. In short, in the face of a growing incidence of childhood cancer cases, therapeutic advances seem to be failing to make inroads. But, in this scenario, there emerges a question: could application of today’s most advanced molecular imaging techniques help to boost the effectiveness of childhood cancer diagnosis and treatment? This is clearly a hypothesis worth addressing, but given that these techniques, such as positron emission tomography (PET), used alone or in combination with x-ray computed tomography (CT), are based on use of ionising radiation, it is also one that immediately raises the problem of potential radiation burden, known to be a much more critical issue in children than in adults. Indeed, because of concerns over radiation exposure, but also problems linked to long scan acquisition times and the need for sedation in young children, imaging studies in children tend to be restricted to patients in whom the study is absolutely crucial for the diagnosis, treatment planning and follow-up, when other modalities have failed to provide conclusive information. “Focus on...” abridgements aim to highlight papers published within the past year and draw extensively on the texts and summaries of the articles referenced. Less recent citations are also included when deemed useful to provide background information on the topic reviewed.

SNMMI and EANM guidelines for diuretic renography in children

Dear Sir, I read the interesting letter by De Man K al. [1]. It is true that there are discrepancies between the SNMMI [2 ]a nd EANM [3] guidelines for diuretic renography in children. Both we and our North American colleagues are aware ofthisproblem, and the SNMMI and EANM paediatric committees began to discuss harmonisation a couple of years ago, starting with the injected activities. The goal of having common guidelines for all procedures is drawing closer to realisation with every day that passes; indeed, we expect to begin publishing common updated guidelines next year. Coming to letter, I would like to comment on the background to the guidelines and to address differences in respect of hydration and catheterisation. First, it must be underlined that the SNMMI guidelines (whose newest reference date is 2006) are more technically driven (and were published in the J Nucl Med Technol), whilst the EANM guidelines are more evidence based/evidence oriented; this probably reflects differences in working organisation. The preference of the SNMMI for intravenous hydration and catheterisation is very likely related to their desire for reproducible mathematical analysis of the drainage pattern. A large body of literature now demonstrates that, even in a highly standardised setting, the positive diagnosis of obstruction is impossible with a single diuretic renogram and can be achieved only during integrated instrumental follow-up. This is why the EANM guidelines suggest the lowest degree of invasiveness (oral hydration and no catheterisation) and the necessity for (and reliability of) the post-micturition acquisition and calculation of output efficiency/normalised residual activity. In conclusion, on behalf of the EANM Paediatric Committee, we still recommend use of our guidelines, in conjunction with continuing clinical cooperation with the referring urologist, which is indispensable.