Performance of quantitative measurements in [18F]fluorocholine positron emission tomography/computed tomography for parathyroid imaging (P2TH study).

Objective: [18F]Fluorocholine positron emission tomography/computed tomography (PET/CT) is used frequently in addition to [99mTc]Tc-Sestamibi scintigraphy and ultrasonography for the location of hyperfunctioning parathyroid glands. The aim of this study is to evaluate the performance of quantitative criteria in [18F]fluorocholine PET/CT for localization of hyperfunctioning parathyroid glands. The secondary objective is to highlight a correlation between the detection rate of [18F]fluorocholine PET/CT and serum parathyroid hormone (PTH) level. Materials and methods: In two academic centers, we retrospectively included patients with biological hyperparathyroidism (HPT) and who had [18F]fluorocholine PET/CT. After a visual analysis, to measure the overall performance of [18F]fluorocholine PET/CT, a blind reading was carried out with standardized measurements of maximum standardized uptake value (SUVmax), liver ratio, thyroid ratio, and size ratio. We analyzed the quantitative criteria of [18F]fluorocholine PET/CT compared to the histological results, in particular to identify differences between adenomas and hyperplasias. We compared the performance of each quantitative criterion to the overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of [18F]fluorocholine PET/CT. The detection rate of hyperfunctioning parathyroid glands was calculated in subgroups of serum PTH level. Results: The quantitative criteria in [18F]fluorocholine PET/CT were measured for 120 patients (135 lesions). The areas under the receiver operating characteristic (ROC) curve representing SUVmax and liver ratio were significantly increased. The optimal cut-off values represented by the maximum Youden index was >4.12 for SUVmax and >27.4 for liver ratio. Beyond certain threshold values of SUVmax (>4.12) or liver ratio (>38.1), all the lesions were histologically proven adenomas. SUVmax and liver ratio were significantly higher for adenomas than for hyperplasias and differential diagnosis (p = 0.0085 and p = 0.0002). The positivity of [18F]fluorocholine PET/CT was correlated with PTH level. Detection rates were 55.56, 75.56, and 87.5%, respectively, for serum PTH < 70, 70 to 120, and >120 ng/ml. Conclusion: Semi-quantitative measurements (SUVmax and liver ratio) should be considered as additional tools in interpretation of [18F]fluorocholine PET/CT. These quantitative parameters have lower overall performance but higher specificity than overall visual analysis in identifying an adenoma. Above certain threshold values, all lesions are adenomas. [18F]fluorocholine PET/CT confirms excellent performance for the detection of hyperfunctional parathyroids. For serum PTH levels < 70 ng/ml, the detection rate of [18F]fluorocholine PET/CT is strongly decreased.

Diagnostic Performance of 18F-Choline Positron Emission Tomography/Contrast-Enhanced Computed Tomography in Adenoma Detection in Primary Hyperparathyroidism after Inconclusive Imaging: A Retrospective Study of 215 Patients.

This large, retrospective, single-centre study evaluated the diagnostic performance of 18F-choline positron emission tomography/contrast-enhanced computed tomography (PET/ceCT) in preoperative parathyroid adenoma detection in primary hyperparathyroidism cases after negative/inconclusive ultrasound or other imaging findings. We included patients who underwent surgery and 18F-choline PET/ceCT for inconclusive imaging results between 2015 and 2020. We compared the 18F-choline PET/ceCT results with surgical and histopathological findings and identified the variables influencing the correlation between 18F-choline PET/ceCT and surgical findings. Of 215 enrolled patients, 269 glands (mean lesion size, 10.9 ± 8.0 mm) were analysed. There were 165 unilocular and 50 multilocular lesions; the mean preoperative calcium level was 2.18 ± 0.19 mmol/L. Among 860 estimated lesions, 219 were classified as true positive, 21 as false positive, and 28 as false negative. The per-lesion sensitivity was 88.66%; specificity, 96.57%; positive predictive value, 91.40%; and negative predictive value, 95.39%. The detection and cure rates were 82.0% and 95.0%, respectively. On univariate and multivariate analyses, the maximum standardised uptake value (SUVmax), lesion size, and unilocularity correlated with the pathologic findings of hyperfunctioning glands. 18F-choline PET/ceCT presents favourable diagnostic performance as a second-line imaging method, with SUVmax, lesion size, and unilocularity predicting a high correlation between the 18F-choline PET/ceCT and surgical findings.

Long-term use of liposomal nebulized amikacin and tedizolid for the treatment of disseminated nocardiosis after allogeneic hematopoietic stem cell transplantation.

Nocardiosis is a life-threatening opportunistic infection in immunocompromised patients. Herein, we present successful adjunctive use of liposomal nebulized amikacin and tedizolid in a recipient of allogeneic hematopoietic stem cell transplantation infected with Nocardia nova complex who presented multiple complications to conventional therapeutic options.

99mTc-white blood cell SPECT/CT to assess diabetic foot osteomyelitis remission: contribution of semi-quantitative scoring system.

AIMS: We previously reported that 99mTc-White blood cell (WBC) single-photon emission computed tomography (SPECT/CT) could be a useful tool to assess diabetic foot osteomyelitis (DFO) remission and guide the duration of antibiotic treatment. The aim of the present study was to evaluate the performance and reproducibility of two analysis methods to diagnose DFO remission using 99mTc-WBC-SPECT/CT. METHODS: 99mTc-WBC-SPECT/CT performed for patients with DFO at the end of antibiotic treatment were retrospectively read by two nuclear physicians (one senior and one junior). Assessment by conventional visual analysis and by the use of a semi-quantitative scoring system, the composite score index (CSI), was performed. The performance and reproducibility of methods were compared between the two nuclear physicians. Successful treatment of DFO was defined by the absence of DFO relapse at the same site within 1 year. RESULTS: A total of 68 patients with 74 DFO were included. Three were excluded from the analysis due to the low quality of SPECT/CT; among the 71 DFO analyzed, 11 (15.5%) had a relapse during follow-up. Performances of 99mTc-WBC-SPECT/CT to predict DFO remission with conventional visual assessment were significantly lower for junior than for senior nuclear physician with moderate inter-rater agreement (Kappa: 0.417). Performances with the use of CSI were similar between the two readers with good inter-rater agreement (Kappa: 0.756). CONCLUSION: The study found that conventional visual assessment of 99mTc-WBC-SPECT/CT to assess DFO remission requires experience, and supported that CSI could be useful for junior nuclear physician to discriminate residual infections and inflammatory post-treatment uptake.

Compatibility of [99mTc]Tc-EDDA/HYNIC-TOC and [68Ga] Ga-DOTA-TOC in a syringe for intravenous administration.

OBJECTIVE: Drug quality in medical devices is not evaluated during the marketing authorization of radiopharmaceuticals. Therefore, the extemporaneous change of packaging made for preparation of patient unit doses in a syringe is the responsibility of radiopharmacists. The present study aimed to determine the impact of packaging and storage in a polypropylene syringe on the quality of hydrophilic drugs [Tc]Tc-EDDA/HYNIC-TOC (Tektrotyd) and [Ga]Ga-DOTA-TOC (Somakit-TOC). METHODS: Appearance, pH, radiochemical purity, sterility, and endotoxin tests were performed according the current European Pharmacopoeia. Subvisible and visible particles tests of the European Pharmacopoeia were adapted due to limited preparation volume (<25 ml). Sorption tests were performed according to the literature. RESULTS: After 2 h storage in a syringe, drug sorption of Tektrotyd and Somakit-TOC was of less than 2.5% and similar to other Tc-radiopharmaceuticals (range: from 1.1 ± 0.5% to 4.2 ± 0.6%). For Tektrotyd, this sorption phenomenon was positively influenced by the drug concentration and a short contact with the medical device (4.8 ± 0.2% up to 5 s vs. 2.3 ± 0.2%, n = 4; P < 0.001). For Somakit-TOC, the duration of contact with syringe had no impact (1.6 ± 0.2% up to 5 s vs. 1.7 ± 0.6%; P = 1.000). No drug radiolysis or alteration of microbiological aspects were observed. No impurity from a 3-piece-syringe was observed according to drug aspect, pH, and subvisible and visible particles, which remained within specification of the current European Pharmacopoeia. CONCLUSION: This study found that drug sorption to packaging was compatible with clinical use and absence of drug alteration of Tektrotyd and Somakit-TOC after repackaging in a syringe in polypropylene and prolonged storage during 2 h.

Application of white blood cell SPECT/CT to predict remission after a 6 or 12 week course of antibiotic treatment for diabetic foot osteomyelitis.

AIMS/HYPOTHESIS: Diabetic foot osteomyelitis is a major risk factor for amputation. Medical treatment allows remission in 53-82% of cases. However, the optimal duration of antibiotic therapy remains controversial as a validated marker of osteomyelitis remission is lacking. The aim of this cohort study was to assess prospectively the remission rate of diabetic foot osteomyelitis medically treated using white blood cell (WBC)-single-photon emission computed tomography (SPECT)/computed tomography (CT) as a predictive marker of remission. METHODS: Individuals with diabetic foot osteomyelitis that was non-surgically treated between April 2014 and December 2015 were included. All participants were treated with antibiotics alone. WBC-SPECT/CT was performed at 6 weeks and antibiotic treatment discontinued if the clinical signs of soft-tissue infection had resolved and there was no abnormal uptake of labelled WBCs. Treatment was otherwise continued for a total of 12 weeks and then discontinued. For these individuals, another WBC-SPECT/CT was performed at 12 weeks. Remission was defined as the absence of recurrence of osteomyelitis at the same location at 1 year. RESULTS: Forty-five individuals were included; overall remission rate was 84% at 1 year. A 6 week course of antibiotics was used in 23 participants, 22 of whom were in remission at 1 year (96%); a 12 week course was used for 22 participants, 16 of whom were in remission at 1 year (73%). Sensitivity of WBC-SPECT/CT at 12 weeks was 100%, specificity 56%, positive predictive value 46% and negative predictive value 100%. CONCLUSIONS/INTERPRETATION: The study suggests that WBC-SPECT/CT could predict remission at the end of antibiotic treatment. TRIAL REGISTRATION: ClinicalTrials.gov NCT02927678.

The role of radionuclide imaging in the surgical management of primary hyperparathyroidism.

Primary hyperparathyroidism is a frequent and potentially debilitating endocrine disorder for which surgery is the only curative treatment. The modalities of parathyroid surgery have changed over the last 2 decades, as conventional bilateral neck exploration is no longer the only surgical approach. Parathyroid scintigraphy plays a major role in defining the surgical strategy, given its ability to orient a targeted (focused) parathyroidectomy and to recognize ectopic locations or multiglandular disease. This review, which represents a collaborative effort between nuclear physicians, endocrinologists, and endocrine surgeons, emphasizes the importance of performing imaging before any surgery for primary hyperparathyroidism, even in the case of conventional bilateral neck exploration. We discuss the advantages and drawbacks of targeted parathyroidectomy and the performance of various scintigraphic protocols to guide limited surgery. We also discuss the optimal strategy to localize the offending gland before reoperation for persistent or recurrent hyperparathyroidism. Finally, we describe the potential applications of novel PET tracers, with special emphasis on (18)F-fluorocholine.

Atypical femoral head osteonecrosis: a case report.

We report the case of a 65-year-old man presented with polymyalgia rheumatica. After a week on corticosteroid (40 mg/d), pain was relieved rapidly. Bone scan, requested to precisely localize osteoarticular lesions, showed high uptake in the external aspect of the head of left femur. In the clinical setting, bone scan and MRI appearances are suggestive of osteonecrosis, probably of recent onset. The final diagnosis of atypical necrosis of the femoral head, most probably secondary to corticoid therapy, was thus established.

Is scintigraphic double-track appearance a sign of severe acute episodes of ulcerative colitis?

AIM: In comparison to endoscopy, clinical and biological criteria are less predictive of severity in attacks of ulcerative colitis (UC). Our aim was to assess the value of the double-track scintigraphic appearance in the assessment of the severity of acute UC by comparing it to endoscopic criteria. PATIENTS AND METHODS: We reviewed medical records of 52 patients hospitalized for an acute attack of UC, who had undergone within 48 hours of presentation both a technetium 99m hexamethyl propylene amine oxime (99mTc-HMPAO) granulocyte scintigraphy and endoscopic examination (colonoscopy: n=20; rectosigmoidoscopy: n=32). RESULTS: Taking into account the colonic segments examined together with both methods in the same patient or results obtained with colonoscopies, there was an excellent agreement between the double-track scintigraphic appearance and endoscopic criteria of severity. CONCLUSION: In patients with previously diagnosed UC, 99mTc-HMPAO granulocyte scintigraphy when available may replace endoscopic examination to assess the severity of attacks.