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ObjectivesIn the context of a supply disruption of mebrofenin (Cholediam)-based kits for radiolabelling with technetium-99m [99mTc], the medicine agencies allowed the importation of a back-up radiopharmaceutical diagnostic agent, etifenin (Techida), to ensure continuous management of patients with hepatobiliary disorders in nuclear medicine departments. There are still issues regarding the measurement of radiochemical purity (RCP) with these kits based on the European Pharmacopoeia and the Summary of Product Characteristics (SPC). This study aims to identify and to optimise, in a clinical context, the most suitable thin layer chromatography (TLC) method for the determination of the RCP in terms of speed of response and reliability for [99mTc]Tc-mebrofenin and [99mTc]Tc-etifenin.Methods[99mTc]Tc-etifenin (n=4) and [99mTc]Tc-mebrofenin (n=5) were individually controlled using six different TLC methods and one high-performance liquid chromatography (HPLC) method for impurity identification ([99mTc](TcO2)nand Na[99mTc]TcO4), RCP (%) and duration of analysis (min). Two TLC methods were selected according to the recommendations of the Pharmacopoeia and SPC, two others were exactly the same but with a heating step, and the other two corresponded to a mix between the methods of the SPC and the Pharmacopoeia that were chosen to optimise RCP determination parameters.ResultsRadio-HPLC analysis allowed effective separation of [99mTc]Tc-etifenin and [99mTc]Tc-mebrofenin with a retention time of 8.05±0.02 min and 8.94±0.07 min, respectively, from Na[99mTc]TcO4(retention time 2.76±0.03 min). HPLC showed an absence of Na[99mTc]TcO4for [99mTc]Tc-mebrofenin and 0.2% for [99mTc]Tc-etifenin. Among the TLC methods, we identified the most suitable method which ensures the most compliant RCP (98.3±0.9%) in a time of 31.5±1.1 min. Also, it allowed a time saving of 15 min compared with the methods proposed by the Pharmacopoeia and the SPCs.ConclusionWe propose a TLC method that accelerates quality control by an average of 15 min while guaranteeing a reliable RCP.

ObjectivesTechnetium-99m mercapto-acetyl-triglycine ([99mTc]Tc-MAG3) is a radiopharmaceutical diagnostic agent used in nuclear medicine intended for the exploration of nephrological and urological disorders. Patient safety and reliability of this imaging procedure especially depend on the radiochemical purity (RCP) of the [99mTc]Tc-MAG3 preparation. Recently, the Summary of Product Characteristics (SPC) of NephroMAG, a kit dedicated to [99mTc]Tc-MAG3 preparation, proposed a two-strip thin layer chromatography (TLC) based quality control (QC) method. Also, Straub et alrecently proposed another TLC based QC method. We sought to evaluate the transferability of these QC methods in our hospital radiopharmacy and compared them to our currently employed TLC method and radio-HPLC (high-pressure liquid chromatography) to select the most appropriate in the context of hospital radiopharmacy.MethodsTen consecutive [99mTc]Tc-MAG3 preparations were controlled using: HPLC combined with a radiodetector (radio-HPLC), a single strip TLC method (method 1) in current use in our centre, a two-strip TLC method described in the SPC (method SPC) and a two-strip TLC method (method 2) described by Straub et al. Quantitative results for the four tested QC methods were measured and compared in terms of RCP (%), sodium pertechnetate ([99mTc]TcO4−) (%) and duration of analysis (min).ResultsRCP was significantly different between method SPC and radio-HPLC (p<0.001) and method 2 (p<0.001). Also, the percentage of [99mTc]TcO4−was statistically different between the radio-HPLC and the method SPC (p<0.001), but not with the method 1 and method 2 group (p>0.05). The duration of analysis (min) was significantly different between the four QC procedures (p<0.001) with method 2 and method SPC being the quickest.ConclusionsOur study showed it is possible to transfer and select a quick and reliable QC method for the preparation of NephroMAG kits in our centre. We therefore advise the widespread use of the method from Straub et alin hospital radiopharmacies.

Radioiodine therapy using oral administration of Iodine-131 (131I) is a widespread employed strategy for the treatment of hyperthyroidism and thyroid cancer. Such a therapy requires well-trained staff, equipment and procedures regarding radiation safety. The aims of this work are to report an incidental experience of radioprotection with a 370 MBq sodium [131I] iodide capsule, which arose following vomiting one minute after the oral administration in a nuclear medicine department and assessment of capsule leakage in a stomach like environment by in vitro experiment. Measurements of the radiation dose rate at the different steps of the decontamination procedure were performed and management of the situation described. Dose rate in vomit was 113 µSv/h [directional dose equivalent H’(0.07)] after capsule withdrawal and was decreased by 10 times after the first decontamination attempt. To evaluate the 131I release following administration to the patient, an in vitro experiment was designed to recap capsules degradation in a stomach like environment including acidic solution (pH 1) and temperature at 35–37°c. A significant release of 131I (<6%) was observed in the first 2 min of the in vitro experiment. Sodium [131I] iodide capsules disruption occurred at 150 s for capsule 1 and 133 s for capsule 2. Incidental contamination with 131I in the clinics is of important concern in nuclear medicine and precautions that allow optimization and pertinent management of the situation should be known by the nuclear medicine and radioprotection community.

The TEKCIS technetium-99m (99mTc) generator was designed to allow dry column shipment and automatized conception. A high 99mTc radioactive concentration is required in a subset of radiopharmacy procedures. Fractionated elution can be a useful tool to meet this requirement, especially when current elution is close to the generator expiration date. The aim of our study was to assess TEKCIS generator elution kinetics and to determine the optimal fractionated elution time to fit with procedures requiring the highest 99mTc radioactive concentration in clinical use. After duplicate elution at several predetermined elution times, the volume and activity of each eluate were measured. Two optimal time points were selected to perform fractionated elution and repeatability (n=34 and 33) assessed on TEKCIS generators calibrated at 6 or 8 GBq. The complete eluate volume (5 ml) was collected after 60 s of elution. A logarithmic equation was established between eluate volume (v, ml) from elapsed elution time (t, s): v=1.8335ln(t)−2.5965. Using the reciprocal equation, elution times required to obtain some commonly eluted volumes were calculated. Fractionated elutions during 15 and 20 s were selected and an average elution volume from 2.74 to 3.27 ml was collected, with an average elution yield of approximately 90 and 100%, respectively. Our work provides a simple and reliable methodology for the use of fractionated elution with the new TEKCIS generator.

ABSTRACTDuring the last decade, growing efforts have focused on human papillomavirus (HPV) detection using liquid hybridization, conventional PCR, and real-time PCR-based methods to increase the overall proportion of patients participating in cervical cancer screening procedures. We proposed a new general HPV DNA real-time PCR on the Mx4000 (Stratagene) and LightCycler (Roche Diagnostics) systems usable for both cervical scrape specimens and urine samples. A linear range was obtained from 5 DNA copies to 8 log10DNA copies/ml, and intra- and interassay variations were between 1.8 and 4%. Cervical carcinoma and HPV DNA screening was performed in 333 individual women referred for gynecological examination at the university hospitals of Angers and Brest and enrolled in the PapU study. Among cervical specimens (n= 333), 45% were positive for HPV DNA, with a mean viral load at 5.00 log/ml (± 1.73). Among urine samples (n= 177), 37% were positive with a significant 50-fold-lower mean viral load (3.77 ± 1.32 log/ml; P< 0.0001). Kappa agreement for HPV DNA between cervical and urine specimens was excellent (93%). Thus, we developed a highly sensitive and quantitative general HPV DNA real-time PCR method that allows mass screening of patients with HPV infection. The ongoing longitudinal and prospective multicenter PapU study should give us the opportunity to validate this method adapted to HPV DNA screening in urine samples in a larger population.