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Multicentre Studies
Published in Michael Ljungberg, Handbook of Nuclear Medicine and Molecular Imaging for Physicists, 2022
Terez Sera, Ronald Boellaard, Andres Kaalep, Michael Ljungberg
A series of national QC studies were performed to evaluate clinical renal scintigraphy studies. Because this study involved the imaging of a rapid redistribution of activity in the body, it was extremely difficult to create a physical phantom that mimicked blood flow through the kidneys into the bladder in a realistic manner. An alternative method is to create a pharmacokinetic model that mimics 99mTc-MAG3 and then simulates dynamic imaging. For this, the pharmacokinetic model developed by Brolin and colleagues [54] was referred to. Because the model maintained the total activity, the Poisson noise level added after the simulations in certain regions of the image was correct. Figure 27.5 shows simulated renography projections of six time points for a camera with perfect spatial resolution and a camera with realistic attenuation and scatter effects as well as collimator resolution with Poisson noise added.
Breast Imaging with Radiolabeled Peptides
Published in Raymond Taillefer, Iraj Khalkhali, Alan D. Waxman, Hans J. Biersack, Radionuclide Imaging of the Breast, 2021
Eric P. Krenning, Marion de Jong, Roelf Valkema, Casper H.J. van Eijck
Planar and SPECT studies are preferably performed 24 hours after injection of the radiopharmaceutical. Planar studies after 24 and 48 hours can be carried out with the same protocol. Repeat scintigraphy after 48 hours is especially indicated when 24-hour scintigraphy shows accumulation in the abdomen, which may also represent radioactive bowel content.
Thyroid cancer
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Gitta Madani, Polly S Richards
The main role of scintigraphy is in the assessment of whole gland or nodule function. Thyroid scintigraphy is only used in the work-up of thyroid nodules, in patients with biochemical evidence of hyperthyroidism and low thyroid-stimulating hormone (TSH). 99mTechnetium (99mTc) pertechnetate is used as the baseline imaging study to evaluate the anatomical location and trapping function of thyroid nodules; it has no role to play in the detection of metastatic or recurrent disease and only occasionally is taken up by metastatic cervical nodes.123Iodine (123I) is also used to evaluate the function of thyroid nodules. It may be performed after 99mTc pertechnetate if the result is equivocal. 123I is used to detect metastatic disease postoperatively. 131I plays a major role in the treatment and follow-up of patients with thyroid cancer.
Progress in large field-of-view interventional planar scintigraphy and SPECT imaging
Published in Expert Review of Medical Devices, 2022
Martijn M.A. Dietze, Hugo W.A.M de Jong
Large field-of-view interventional imaging could aid such intra-arterial radionuclide therapy procedures in two ways. First, similar to radioembolization, direct feedback on the radiopharmaceutical injection is obtained using dynamic planar scintigraphy. This allows the physician to change the injection position should an incorrect distribution be observed. Ideally, planar scintigraphic imaging would simultaneously be coupled to anatomical images, such as the x-ray images acquired from a CBCT scanner. And second, nuclear image guidance can be performed for dosimetric purposes. With planar scintigraphy and SPECT, it can be studied at which point the uptake of radiopharmaceutical in a tumor saturates. Such image guidance hence allows to maximize the dose or ensure a minimal effective dose that is being administered to the tumor. With quantitative SPECT imaging, the absolute doses to the tissues can furthermore be calculated and monitored during the procedure.
Single-session high-intensity focused ultrasound (HIFU) ablation for benign thyroid nodules: a systematic review
Published in Expert Review of Medical Devices, 2020
Eleftherios Spartalis, Sotirios P. Karagiannis, Nikolaos Plakopitis, Maria Anna Theodori, Dimosthenis Chrysikos, Stavroula A. Paschou, Georgios Boutzios, Dimitrios Schizas, Michael Spartalis, Theodore Troupis, Nikolaos Nikiteas
Among the independent factors of treatment success, one worth highlighting is the appearance of HEMs on the US, which represent microbubbles and cavities generated by thermal tissue ablation via focused US energy [22]. According to Lang et al [22], the appearance of HEMs on at least one occasion post-ablation correlated to a remarkably increased likelihood of treatment success; the proportion of HEMs is not significant. Lower Body Mass Index (BMI) and the application of greater power increase the chance of HEM appearance [22]. Besides, scintigraphy can be utilized to assess the ablation outcome [32]. Korkusuz et al reported a 99mTc-pertechnetate uptake reduction for hot or indifferent nodules and a 99mTc-MIBI uptake reduction for cold nodules one day after treatment [32]. Radioisotope uptake reduction was negatively correlated with nodule volume. Although these findings were of low significance, they show the promising role of scintigraphy as an evaluation modality for treatment success. Furthermore, measuring anti-Tg levels on the fourth day after intervention could contribute in determining the efficacy of ablation in anti-Tg-positive patients (anti-Tg > 99 mL) [33], as a percentage of anti-Tg drop (%) on the fourth day post-treatment significantly correlated with VRR at 6 months and treatment success. On the other hand, the extent of serum Tg rise (%) did not significantly correlate with VRR at 6 months and ablation success, regardless of patients’ anti-Tg status [33,34], thus excluding it as a potential factor for predicting nodule shrinkage.
Comparative studies on the potential use of 177Lu-based radiopharmaceuticals for the palliative therapy of bone metastases
Published in International Journal of Radiation Biology, 2020
Hesham M. H. Zakaly, Mostafa Y. A. Mostafa, Darya Deryabina, Michael Zhukovsky
The absorbed dose in bone tissue for different types of cancer using the same drug will be different. The difference is due to the different proportions of osteoblastic and osteolytic activity in the lesions, bone density, blood flow in the tumor, the presence of intra-tumor necrosis or hypoxia and the number and size of metastatic lesions. It is noted that the absorbed dose in the bone marrow of patients with prostate cancer is much higher than with breast cancer (A. Wilky 2013). Therefore, it is particularly important to conduct scintigraphy during treatment to monitor the distribution of the drug and to correct the dosage of the radiopharmaceutical. At the moment, activity can only be corrected at the initial stage of therapy in order to vary the activity of the drug depending on the weight of the patient. To obtain optimal efficacy in relation to the drug 153Sm-EDTMP’s toxicity, injection activity was adjusted for a specific patient as 37 MBq/kg weight. Finally, from the obtained results and in comparison, with others, 177Lu-EDTMP and 177Lu-MDP are presented as the recommended radiopharmaceuticals for bone metastases.