The new EANM paediatric dosage card

Ultrafast cadmium-zinc-telluride-based renal single-photon emission computed tomography: clinical validation

BACKGROUND

One of the main limitations of 99mtechnetium-dimercaptosuccinic acid (DMSA) scan is the long acquisition time.

OBJECTIVE

To evaluate the feasibility of short DMSA scan acquisition times using a cadmium-zinc-telluride-based single-photon emission computed tomography (SPECT) system in children.

MATERIALS AND METHODS

The data of 27 children (median age: 4 years; 16 girls) who underwent DMSA SPECT were retrospectively analyzed. Both planar and SPECT DMSA were performed. SPECT images were analyzed using coronal-simulated planar two-dimensional images. A reduction in SPECT acquisition time was simulated to provide 4 series (SPECT-15 min, SPECT-10 min, SPECT-5 min and SPECT-2.5 min). A direct comparison of the planar and SPECT series was performed, including semi-quantification reproducibility, image quality (mean quality score on a scale of 0 to 2) and inter- and intra-observer reproducibility of the scintigraphic patterns.

RESULTS

The overall image quality score (± standard deviation) was 1.3 (± 0.6) for the planar data set, 1.6 (± 0.5) for the SPECT-15 min data set, 1.4 (± 0.5) for the SPECT-10 min data set, 1.0 (± 0.5) for the SPECT-5 min data set and 0.6 (± 0.6) for the SPECT-2.5 min data set. Median Kappa coefficients for inter-observer agreement between planar and SPECT images were greater than 0.83 for all series and all readers except one reader for the SPECT-2.5 min series (median Kappa coefficient = 0.77).

CONCLUSION

Shortening SPECT acquisitions to 5 min is feasible with minimal impact on images in terms of quality and reproducibility.

Technical feasibility, radiation dosimetry and clinical use of 18F-sodium fluoride (NaF) in evaluation of metastatic bone disease in pediatric population

PURPOSE

The role of ¹⁸F-fluoride (¹⁸F-NaF) PET-CT for the detection of bone metastases in adults is well established and is considered superior to conventional bone scintigraphy. However, data pertaining use of ¹⁸F-NaF PET-CT in pediatric oncology is relatively sparse. The aim of the present study is to retrospectively analyze and share a single-center experience of ¹⁸F-NaF PET-CT in pediatric population and to provide preliminary information regarding imaging technique, feasibility of this modality in young patients and radiation dosimetry measurements in pediatric oncology cases.

MATERIALS AND METHODS

Twenty-four pediatric patients (mean age 8.0 ± 3.9) were included in the study for retrospective analysis. All patients were referred for primary staging or restaging for potential osseous metastatic disease and PET-CT scan was performed by injecting 2.2 MBq/kg (0.06 mCi/kg) of ¹⁸F-NaF.

RESULTS

Nine patients were imaged for primary staging and in all cases increase osteoblastic activity was seen in the primary tumor and of these, metastatic bone disease was identified in 2/9 patients. In the restaging group comprising 15/24 patients, metastatic deposits were identified in 3/15 whilst no disease was seen in the remaining 12 patients. Patients were injected a mean dose of 90.35 ± 22.9 MBq with an estimated mean effective absorbed doses of 2.98 ± 0.75 mSv for ¹⁸F-NaF and 3.37 ± 2.4 mSv for CT alone. Mean cumulative effective dose of ¹⁸F-NaF PET-CT scan was 5.11 ± 2.7 mSv.

CONCLUSIONS

¹⁸F-NaF PET-CT may be a feasible alternative to ^99mTc MDP for radionuclide bone scintigraphy in the evaluation of pediatric bone pathology. Due to its better pharmacokinetics, there is potential that osseous staging can be achieved with relatively low doses and with a similar radiation burden as with ^99mTc-MDP imaging.

Interobserver agreement on cortical tracer transit in 99mTc-MAG3 renography applied to congenital hydronephrosis

OBJECTIVE

This study aims to evaluate interobserver agreement on visual analysis of technetium-99m mercaptoacetyltriglycine (Tc-MAG3) renal tissue transit used for the evaluation of antenatal hydronephrosis.

MATERIALS AND METHODS

Thirty-eight Tc-MAG3 diuretic renograms were retrospectively collected between 1 and 31 December 2015. The 1-min reframed images were presented to four nuclear medicine consultants and to two nuclear medicine residents, one in the first year of the training program and the others in their fourth and final year. These observers were asked to classify the radiotracer cortical transit (normal/delayed) based solely on visual assessment of the images. For the interobserver agreement, modified Fleiss' kappa (κ) analysis for multiple raters was carried out. For both groups, percentages of agreement were also calculated.

RESULTS

A total of 69 kidneys were evaluated. All four nuclear medicine consultants agreed on the classification of 88.4% of the kidneys. When the agreement of at least three of the four observers was considered, the percentage of agreement reached 98.6%. The two nuclear medicine residents agreed on the classification of 69.6% of the kidneys. The modified Fleiss' κ-value was 0.88 (95% confidence interval: 0.79-0.95) for the group of nuclear medicine consultants, indicating almost perfect agreement. For the residents, it was 0.39 (95% confidence interval: 0.16-0.59), suggesting fair agreement.

CONCLUSION

Our results seem to indicate that there is an almost perfect agreement in the qualitative identification of delayed cortical transit among physicians with experience at observing renographic images.

Quantitative sacroiliac scintigraphy for pediatric patients: comparison of two methods

OBJECTIVE

Quantitative bone scintigraphy is a useful method to diagnose sacroiliitis. However, there is significant overlap between healthy and pathological sacroiliac index (SI) values for adult patients, while there are no such sufficient data for children. This study was aimed mainly to assess normal SI values in different age groups of pediatric patients using 2 different quantitative methods.

MATERIALS AND METHODS

Normally reported bone scans of 79 children were retrospectively reviewed. Two different methods were used for quantitation. For the first method, sacrum was used as a background site while L5 vertebra was used instead for the second method. Right/left SI values of both methods were compared with each other in relation with gender and different age groups, as group 1 (1-5 years), group 2 (6-10 years), group 3 (11-15 years) and group 4 (16-18 years). Additional comparison was made with a group of young-adult population of 21-30 years old as group 5 to assess the effect of age.

RESULTS

Gender-based comparison yielded significantly higher SI for females for the first method, while no significant difference existed for the second one. Significant increase in SI with both methods was found as age increased. Significantly lower SI was found from the second method, when similar age groups like group 1-2 or group 2-3 were compared with each other, while no such difference existed for the first method. For each individual patient from any age group, method-based comparison resulted in a significantly different SI with both methods.

CONCLUSIONS

In pediatric population, SI tends to increase as age increases. Quantitation method using sacrum as background yields significantly higher SI for female gender. Alternative use of L5 as background site for quantitation performs well in children. Since two methods resulted in significantly different SI, individualized cut-off values for each age group for any method are practically warranted.

Guidelines for standard and diuretic renogram in children

Special consideration needs to be given to children who undergo dynamic renography. The Paediatric Committee of the European Association of Nuclear Medicine has updated the previous guidelines. Details are provided on how to manage the child, the equipment, and the acquisition and processing protocols. The pitfalls, difficulties and controversies that are encountered are also discussed, as well as the interpretation of the results.

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 (99m)Tc-labelled diphosphonate scintigraphy, and also recommendations with regard to the emerging use of PET with (18)F-fluoride.