Top-Down versus Bottom-Up Approach in Children Presenting with Urinary Tract Infection: Comparative Effectiveness Analysis Using RIVUR and CUTIE Data.

PURPOSE: The initial imaging approach to children with urinary tract infection (UTI) is controversial. Along with renal/bladder ultrasound, some advocate voiding cystourethrogram (VCUG), ie a bottom-up approach, while others advocate dimercaptosuccinic acid (DMSA) scan, ie a top-down approach. Comparison of these approaches is challenging. In the RIVUR/CUTIE trials, however, all subjects underwent both VCUG and DMSA scan. Our objective was to perform a comparative effectiveness analysis of the bottom-up vs top-down approach. MATERIALS AND METHODS: We simulated 1,000 hypothetical sets of 500 children using RIVUR/CUTIE data. In the top-down approach, patients underwent initial DMSA scan, and only those with renal scarring underwent VCUG. In the bottom-up approach, the initial study was VCUG. We assumed all children with vesicoureteral reflux (VUR) received continuous antibiotic prophylaxis (CAP). Outcomes included recurrent UTI, number of VCUGs and CAP exposure. We assumed a 25% VUR prevalence in children with initial UTI with sensitivity analysis using 40% VUR prevalence. RESULTS: Median age of the original RIVUR/CUTIE cohort was 12 months. First DMSA scan was performed at a median of 8.2 weeks (IQR 5-11.8) after the index UTI. In the simulated cohort, slightly higher yet statistically significantly recurrent UTI was associated with the top-down compared with the bottom-up approach (24.4% vs 18.0%, p=0.045). On the other hand, the bottom-up approach resulted in more VCUG (100% vs 2.4%, p <0.001). Top-down resulted in fewer CAP-exposed patients (25% vs 0.4%, p <0.001) and lower overall CAP exposure (5 vs 162 days/person, p <0.001). Sensitivity analysis was performed with 40% VUR prevalence with similar results. CONCLUSIONS: The top-down approach was associated with slightly higher recurrent UTI. Compared to the bottom-up approach, it significantly reduced the need for VCUG and CAP.

[Management of hemodialysis patient subject to medical-nuclear investigation].

In recent years imaging techniques that use radionuclides have become more and more clinically relevant as they can provide functional information for specific anatomical districts. This has also involved nephrology, where radionuclides are used to study patients with different degrees of renal function failure up to terminal uremia. Although chronic kidney disease, and dialysis in particular, may affect the distribution and the elimination of radiopharmaceuticals, to date there are no consistent data on the risks associated with their use in this clinical context. In addition to the lack of data on the safety of radio-exposure in dialysis patients, there is also a shortage of information concerning the risk for healthcare staff involved in conducting the dialysis sessions performed after a nuclear test. This study, performed on 29 uremic patients who underwent hemodialysis immediately after a scintigraphic examination, assessed the extent of radio-contamination of the staff and of hemodialysis devices such as monitor, kits and dialysate. The data collected has been used to quantify the radiological risk in dialysis after the exposure to the most common radionuclides.

Full report on a survey of adverse reactions to radiopharmaceuticals from 1975 to 2017 in Japan.

OBJECTIVE: This pharmacovigilance-based survey was aimed at determining the prevalence of, and association between, radiopharmaceuticals and adverse reactions to radiopharmaceuticals from 1975 to 2017 in Japan. METHODS: The Subcommittee for Safety Issues of Radiopharmaceuticals of the Japan Radioisotope Association's Medical Science and Pharmaceutical Committee mailed a form for reporting adverse reactions to radiopharmaceuticals to all institutes performing nuclear medicine examinations in Japan. This investigation included adverse reactions to diagnostic radiopharmaceuticals labeled with both single-photon- and positron-emitting radionuclides and therapeutic sodium iodide labeled with 131I. Each institute returned the reporting form to the subcommittee each time an adverse reaction occurred. RESULTS: Replies were obtained from 75% of the institutions. In total, 1099 adverse reactions were reported from 46,645,580 radiopharmaceutical administrations, giving a prevalence of 2.4 adverse reactions per 100,000 administrations (95% confidence interval 2.2-2.5). Adverse reactions were most frequently observed for 131I-iodomethylnorcholesterol (230.1/105 administrations), followed by 131I-HSA (76.3/105 administrations), 131I-sodium iodohippurate (31.2/105 administrations), and 99mTc-DTPA (12.0/105 administrations). Comparison of adverse reactions between before and after 1997 revealed that prevalence dropped from 3.7/105 administrations (95% confidence interval 3.5-4.1) to 1.5/105 administrations (95% confidence interval 1.4-1.6). During the study period, vasovagal reactions accounted for 50.3% of adverse reactions, fever for 7.5%, allergic reactions for 25.7%, and other for 16.5%; 3.7% of all adverse reactions were considered severe but none were lethal. A definite, probable, possible, less likely, and uncertain causal relationship with radiopharmaceuticals was observed in 13.1%, 33.7%, 39.9%, 6.2%, and 7.1% of adverse reactions, respectively. CONCLUSIONS: These results suggest that nuclear medicine staff must be aware of the possibility of adverse reactions from radiopharmaceuticals, despite their rarity.

Barriers and pathways to informed consent for ionising radiation imaging examinations: A qualitative study.

INTRODUCTION: Informed consent for ionising radiation medical imaging examinations represents a recent change to medical imaging practice. This practice has not had a definitive and authoritative integration into clinical practice, and lack of direction has caused many health care professionals to be unsure of an appropriate consent methodology. Consent practices have been undertaken inconsistently and sometimes poorly. This research sought to investigate what barriers exist to meaningful informed consent, and what pathways are suggested to overcome these barriers. These views are then discussed in the context of practical health care consent practices. METHODS: A semi-structured interview explored the views of radiographers and radiologists on the practice of disclosing the ionising radiation risk of a clinical medical imaging examination. Qualitative data was analysed using a nominal method of quantitative transformation. Responses were reviewed, and a set of definitive themes constructed. Participants considered the influences, logistics and barriers to the informed consent process. Participants were then asked what pathways might be developed that would improve the process. RESULTS: Twenty-one (21) radiographer participants and nine (9) radiologists were interviewed. The barriers to consent identified issues of time constraints, lack of a unified message, and patient presentations. Pathways suggested included limiting the scope of the consent practice, sharing the consent responsibility, and formulation of definitive consent guidelines. CONCLUSION: A unified, definitive series of guidelines for informed consent for ionising radiation examinations would alleviate many of the identified barriers. Having the consent process consistently begin with the referring doctor would facilitate more meaningful consent.

Intensive Imaging Surveillance of Survivors of Breast Cancer May Increase Risk of Radiation-induced Malignancy.

BACKGROUND: Current clinical guidelines recommend mammography as the only imaging method for surveillance in asymptomatic survivors of early breast cancer (EBC). However, non-recommended tests are commonly used. We estimated the imaging radiation-induced malignancies (IRIM) risks in survivors of EBC undergoing different imaging surveillance models. MATERIALS AND METHODS: We built 5 theoretical models of imaging surveillance, from annual mammography only (model 1) to increasingly imaging-intensive approaches, including computed tomography (CT) scan, positron emission tomography-CT, bone scan, and multigated acquisition scan (models 2 through 5). Using the National Cancer Institute's Radiation Risk Assessment Tool, we compared the excess lifetime attributable cancer risk (LAR) for hypothetical survivors of EBC starting surveillance at the ages of 30, 60, or 75 years and ending at 81 years. RESULTS: For all age groups analyzed, there is a statistically significant increase in LAR when comparing model 1 with more intensive models. As an example, in a patient beginning surveillance at the age of 60 years, there is a 28.5-fold increase in the IRIM risk when comparing mammography only versus a schedule with mammography plus CT scan of chest-abdomen and bone scan. We found no differences when comparing models 2 through 5. LAR is higher when surveillance starts at a younger age, although the age effect was only statistically significant in model 1. CONCLUSION: Non-recommended imaging during EBC surveillance can be associated with a significant increase in LAR. In addition to the lack of survival benefit, additional tests may have significant IRIM risks and should be avoided.

The SNMMI and EANM practice guideline for renal scintigraphy in adults.

PURPOSE: The Society of Nuclear Medicine and Molecular Imaging (SNMMI) is an international scientific and professional organization founded in 1954 to promote the science, technology, and practical application of nuclear medicine. The European Association of Nuclear Medicine (EANM) is a professional nonprofit medical association that facilitates communication worldwide between individuals pursuing clinical and research excellence in nuclear medicine. The EANM was founded in 1985. SNMMI and EANM members are physicians, technologists, and scientists specializing in the research and practice of nuclear medicine. METHODS: The SNMMI and EANM will periodically define new guidelines for nuclear medicine practice to help advance the science of nuclear medicine and to improve the quality of service to patients throughout the world. Existing practice guidelines will be reviewed for revision or renewal, as appropriate, on their fifth anniversary, or sooner, if indicated. CONCLUSION: Each practice guideline, representing a policy statement by the SNMMI/EANM, has undergone a thorough consensus process in which it has been subjected to extensive review. The SNMMI and EANM recognize that the safe and effective use of diagnostic nuclear medicine imaging requires specific training, skills, and techniques, as described in each document. Reproduction or modification of the published practice guideline by entities not providing these services is not authorized.

The effect of radionuclide solution volume on the detection rate of salivary aspiration in the radionuclide salivagram: A STROBE-compliant retrospective study.

Despite the possibility that the methodological difference of this salivagram may influence the results for detection rate, there has been no study on the effect of the solution volume on detection rate. Moreover, to date, since the introduction of the nucleotide salivagram, there has been a tendency that a constant solution volume and nucleotide dose is not used in studies. Therefore, the aim of this study is to investigate the effect of solution volume on the detection rate of a salivagram in patients with brain lesion, and to determine the optimal solution volume of salivagram. We retrospectively reviewed clinical data and solution volume of radionuclide used in the salivagram of 77 patients with dysphagia, and the patients were divided into 2 groups according to the solution volume of the radionuclide (Group A-0.1 mL vs Group B-0.5 mL). Although, there was no significant difference between 2 groups in clinical data, there was a statistically significant difference in the detection rate of salivary aspiration between the 2 groups (3.3% vs 19.1%). Even a small difference of the solution volume of radionuclide in salivagram can affect the detection rate of salivary aspiration in patients with brain lesion. Further study with various solution volumes of radionuclide is warranted to determine the optimal solution volume of the radionuclide salivagram.

[The choice of diagnostic modality for acute pulmonary embolism].

The diagnosis of pulmonary embolism (PE) relies on clinical assessment, D-dimer test and diagnostic imaging. Modern CT pulmonary angiography (CTPA), ventilation/perfusion  single-photon emission computed tomography (SPECT) and SPECT/CT are rather equal in terms of sensitivity, specificity and inconclusive results for the diagnosis of PE, outper-forming planar lung scintigraphy. Furthermore, SPECT/CT and CTPA can both provide important information regarding differential diagnoses. Thus, the choice of primary diag-nostic modality relies on local expertise, availability and special circumstances like radiation dose, contraindications and the clinical urgency.

What about sentinel lymph node biopsy for early breast cancer during pregnancy?

Pregnancy-associated breast cancer is rare, but this clinical situation arises in 1/10,000-1/3000 pregnancies. In patients presenting an early-stage breast tumor devoid of clinically pathological lymph node, sentinel lymph node (SLN) biopsy has not yet been validated as a routine procedure for pregnant women due to the lack of data in the literature. The blue dye injection is not recommended because of 2% theoretical risk of anaphylactic shock. Several studies have shown that Tc99m injection at conventional dose between 12.1 and 18.5MBq exposed the fetus to an irradiation between 0.011 and 0.0245mSv much below the 50mSv recommended threshold. As evidenced by lymphoscintigraphy scans, the dose of injected Tc99m is localized at the injection site and in the SLN. According to the literature, the SLN technique does not seem to impact the fetal or obstetrical prognosis. Studies involving larger cohorts are required to confirm these data and to indicate this technique in pregnant women. Considering the benefit for the patient and the low risk incurred on both fetal and obstetrical levels, it appears reasonable to discuss the indication of SLN on a case-by-case basis in multidisciplinary oncologic meetings.

Safety and feasibility of breast lesion localization using magnetic seeds (Magseed): a multi-centre, open-label cohort study.

PURPOSE: Wire localization has several disadvantages, notably wire migration and difficulty scheduling the procedure close to surgery. Radioactive seed localization overcomes these disadvantages, but implementation is limited due to radiation safety requirements. Magnetic seeds potentially offer the logistical benefits and transcutaneous detection equivalence of a radioactive seed, with easier implementation. This study was designed to evaluate the feasibility and safety of using magnetic seeds for breast lesion localization. METHODS: A two-centre open-label cohort study to assess the feasibility and safety of magnetic seed (Magseed) localization of breast lesions. Magseeds were placed under radiological guidance into women having total mastectomy surgery. The primary outcome measure was seed migration distance. Secondary outcome measures included accuracy of placement, ease of transcutaneous detection, seed integrity and safety. RESULTS: Twenty-nine Magseeds were placed into the breasts of 28 patients under ultrasound guidance. There was no migration of the seeds between placement and surgery. Twenty-seven seeds were placed directly in the target lesion with the other seeds being 2 and 3 mm away. All seeds were detectable transcutaneously in all breast sizes and at all depths. There were no complications or safety issues. CONCLUSIONS: Magnetic seeds are a feasible and safe method of breast lesion localization. They can be accurately placed, demonstrate no migration in this feasibility study and are detectable in all sizes and depths of breast tissue. Now that safety and feasibility have been demonstrated, further clinical studies are required to evaluate the seed's effectiveness in wide local excision surgery.

Lung uptake during 99mTc-hydroxymethylene diphosphonate scintigraphy in patient with TTR cardiac amyloidosis: An underestimated phenomenon.

BACKGROUND: Full body scintigraphy using bone tracers plays an important role in defining the type of amyloidosis and in diagnosing the heart involvement (cardiac amyloidosis, CA). No study has been conducted to explore lung retention (LR) in CA and its correlation to heart retention (HR).We evaluated LR in patients undergoing 99mTc-HMDP scintigraphy during evaluation for suspected CA. METHODS AND RESULTS: We enrolled 93 suspected CA patients. Patients underwent a complete diagnostic work up. After diagnostic process 82 patients resulted affected by certain CA (20 AL and 62 TTR), while 11 subjects showed left ventricular hypertrophy (LVH) not caused by CA. 99mTc-HMDP cardiac uptake was evaluated using the Perugini visual score while the modified Janssen score was used for LR estimation (grade 0 no uptake, grade 1 less than ribs, grade 2 more than ribs). RESULTS: 99mTc-HMDP LR was observed in 1/20 AL patient (5%), while 36/62 (58%) TTR patients showed LR with 29 grade 1 (47%) and 7 grade 2 (11%). No LR was observed in patients with LVH and no CA. LR was not evident in patients without HR, present in 1/3 (33%) of the patients with Perugini 1 HR and 11/24 (46%) and 26/36 (72%) of the patients showing respectively a Perugini 2 and a Perugini 3. CONCLUSION: 99mTc-HMDP scintigraphy shows LR in about 60% of TTR subjects, related to the grade of HR. In AL amyloidosis LR is less frequent than in TTR amyloidosis suggesting an aetiological tropism that seems comparable to the already known TTR related cardiac tropism.