Journal of nuclear medicine technology最新文献

In a prospective clinical trial, [¹⁸F]fluoro-5α-dihydrotestosterone ([¹⁸F]FDHT), the radiolabeled analog of the androgen dihydrotestosterone, was used as a PET/CT imaging agent for in vivo assessment of metastatic androgen receptor-positive breast cancer in postmenopausal women. To our knowledge, this article presents the first report of PET/CT image-based radiation dosimetry of [¹⁸F]FDHT in women. Methods: [¹⁸F]FDHT PET/CT imaging was performed on a cohort of 11 women at baseline before the start of therapy and at 2 additional time points during selective androgen receptor modulator (SARM) therapy for androgen receptor-positive breast cancer. Volumes of interest (VOIs) were placed over the whole body and within source organs seen on the PET/CT images, and the time-integrated activity coefficients of [¹⁸F]FDHT were derived. The time-integrated activity coefficients for the urinary bladder were calculated using the dynamic urinary bladder model in OLINDA/EXM software, with biologic half-life for urinary excretion derived from VOI measurements of the whole body in postvoid PET/CT images. The time-integrated activity coefficients for all other organs were calculated from VOI measurements in the organs and the physical half-life of ¹⁸F. Organ dose and effective dose calculations were then performed using MIRDcalc, version 1.1. Results: At baseline before SARM therapy, the effective dose for [¹⁸F]FDHT in women was calculated as 0.020 ± 0.0005 mSv/MBq, and the urinary bladder was the organ at risk, with an average absorbed dose of 0.074 ± 0.011 mGy/MBq. Statistically significant decreases in liver SUV or uptake of [¹⁸F]FDHT were found at the 2 additional time points on SARM therapy (linear mixed model, P < 0.05). Likewise, absorbed dose to the liver also decreased by a small but statistically significant amount at the 2 additional time points (linear mixed model, P < 0.05). Neighboring abdominal organs of the gallbladder wall, stomach, pancreas, and adrenals also showed statistically significant decreases in absorbed dose (linear mixed model, P < 0.05). The urinary bladder wall remained the organ at risk at all time points. Absorbed dose to the urinary bladder wall did not show statistically significant changes from baseline at any of the time points (linear mixed model, P ≥ 0.05). Effective dose also did not show statistically significant changes from baseline (linear mixed model, P ≥ 0.05). Conclusion: Effective dose for [¹⁸F]FDHT in women before SARM therapy was calculated as 0.020 ± 0.0005 mSv/MBq. The urinary bladder wall was the organ at risk, with an absorbed dose of 0.074 ± 0.011 mGy/MBq.

In September 2020, the Journal of Nuclear Medicine and Technology published a continuing education article, "Breast Cancer: Evaluating Tumor Estrogen Receptor Status with Molecular Imaging to Increase Response to Therapy and Improve Patient Outcomes," that reviewed a promising new PET tracer, 16α-¹⁸F-fluoro-17β-fluoroestradiol (¹⁸F-FES). This tracer had the potential to be a valuable tool for medical oncologists and breast surgeons in noninvasively evaluating the estrogen receptor site status of their patients' recurrent tumor and secondary metastatic lesions. In May 2020, ¹⁸F-FES received Food and Drug Administration approval and began being marketed by Zionexa using the trade name Cerianna and manufactured by PETNET. In May 2021, GE Healthcare acquired Zionexa, and Cerianna and is now being marketed by GE Healthcare and is still being manufactured by PETNET. This article will review the ¹⁸F-FES package insert information and imaging protocol, as well as important guidelines for imaging with ¹⁸F-FES.

The study aim was to evaluate the adaptation of collimators to ¹²³I-N-fluoropropyl-2b-carbomethoxy-3b-(4-iodophenyl)nortropane (¹²³I-FP-CIT) dopamine transporter SPECT (DAT-SPECT) by a high-resolution whole-body SPECT/CT system with a cadmium-zinc-telluride detector (C-SPECT) in terms of image quality, quantitation, diagnostic performance, and acquisition time. Methods: Using a C-SPECT device equipped with a wide-energy, high-resolution collimator and a medium-energy, high-resolution sensitivity (MEHRS) collimator, we evaluated the image quality and quantification of DAT-SPECT for an anthropomorphic striatal phantom. Ordered-subset expectation maximization iterative reconstruction with resolution recovery, scatter, and attenuation correction was used, and the optimal collimator was determined on the basis of the contrast-to-noise ratio (CNR), percentage contrast, and specific binding ratio. The acquisition time that could be reduced using the optimal collimator was determined. The optimal collimator was used to retrospectively evaluate diagnostic accuracy via receiver-operating-characteristic analysis and specific binding ratios for 41 consecutive patients who underwent DAT-SPECT. Results: When the collimators were compared in the phantom verification, the CNR and percentage contrast were significantly higher for the MEHRS collimator than for the wide-energy high-resolution collimator (P < 0.05). There was no significant difference in the CNR between 30 and 15 min of imaging time using the MEHRS collimator. In the clinical study, the areas under the curve for acquisition times of 30 and 15 min were 0.927 and 0.906, respectively, and the diagnostic accuracies of the DAT-SPECT images did not significantly differ between the 2 times. Conclusion: The MEHRS collimator provided the best results for DAT-SPECT with C-SPECT; shorter acquisition times (<15 min) may be possible with injected activity of 167-186 MBq.

The Nuclear Medicine Technology Certification Board performed an impact survey on the coronavirus disease 2019 pandemic to better assess the current state of nuclear medicine practice within the United States, as well as the perceptions and experiences of technologists working during the pandemic. Methods: A web-based automation platform was used to create, collect, and analyze the survey data. Results: The survey revealed many department protocol variations during the pandemic, a decrease in patient volume, and several other concerns and issues. Experiences regarding staffing and wage changes were varied. Conclusion: This research showed significant inconsistencies in practice and stresses to nuclear medicine technology during the pandemic, as well as concerns for the workforce pipeline. NMTCB decided to delay the JTA process and conduct additional research regarding the workforce.