Imaging Pathway of a Pediatric Patient with Succinate Dehydrogenase B-Deficient Paraganglioma.

Pheochromocytoma and paraganglioma are rare in children, at only 1 in every 50,000 cases. Even though some cases are sporadic, they have been connected to syndromes such as von Hippel-Lindau, multiple endocrine neoplasia types IIa and IIb, neurofibromatosis type 1, and hereditary pheochromocytoma-paraganglioma syndromes. A genetic mutation causes around 60% of pheochromocytomas and paragangliomas in children under 18. Methods: A 15-y-old child with a 6-y history of back discomfort is presented. The justification for using 2 functional imaging modalities, 68Ga-DOTATATE PET/CT and 123I-meta-iodobenzylguanidine SPECT/CT, is examined in this case study. We reviewed the patients' journey since the first referral for imaging. Results: Delaying the molecular imaging modalities has affected patients' overall diagnosis and applied treatment outcomes. Conclusion: This case study investigates the potential for the earlier use of various diagnostic modalities in conjunction with diagnostic testing to facilitate an earlier diagnosis. However, since this study is based solely on imaging and lacks access to the patient's clinical or family history, factors such as potential inequities in health-care facilities, health literacy, and socioeconomic status are not addressed. It is essential to acknowledge these influences as they contribute to the inequitable access to health-care settings in New Zealand.

Stability Matters: Radiochemical Stability of Therapeutic Radiopharmaceutical 177Lu-PSMA I&T.

Labeling radiopharmaceuticals and testing the quality of the labeled product before injecting it into patients are standard operating procedures in the nuclear medicine department. There is a different shelf life for each labeled product, which determines how long a product can maintain in vitro stability before it needs to be discarded. 177Lu is a radioactive isotope that is increasingly being accepted into the treatment paradigm for palliation of advanced-stage tumors, including metastatic castration-resistant prostate cancer (mCRPC) and neuroendocrine tumors (NETs). In our institution, synthesis of 177Lu with prostate-specific membrane antigen imaging and therapy (PSMA I&T) for palliation of mCRPC is performed on an automated synthesis system. Methods: After each synthesis, the final product quality was evaluated by high-performance liquid chromatography (HPLC) and instant thin-layer chromatography (ITLC) at 3 different time points: 0, 24, and 48 h. Between February 2020 and October 2020, the quality of 35 batches of 177Lu-PSMA I&T was evaluated. Results: The average radiochemical purity of ITLC-silica gel was found to be greater than 99% (99.70% ± 0.05%), and HPLC was greater than 98% (98.60% ± 0.05%). Conclusion: Our findings demonstrate that synthesis of 177Lu-PSMA I&T with an automated synthesis system can remain stable for 48 h after labeling.

Lutetium DOTATATE whole body scans: A novel approach for evaluation of neuroendocrine tumors.

AIM: We undertook a study to evaluate whether Lutetium (Lu) DOTATATE whole body scan is well comparable to Gallium positron emission tomography (PET) / Indium Octreotide, and hence with dosimetric advantage can replace it in the pre-therapy setting. MATERIALS AND METHODS: We undertook a prospective study of a total of 39 patients with metastatic neuroendocrine tumor (age 11-70 years), who underwent Lu-DOTATATE scans within the period August 2009-November 2010. This included 28 males and 11 females. Dose of Lu-DOTATATE injected for diagnostic scanning purpose was 10 mCi i.v. Whole body planar images and single-photon emission computed tomography (SPECT)-CT images were obtained at 4, 24 and 48 hours. The Lu-DOTATATE whole body and SPECT-CT images were compared to contrast CT scans in all patients, and Indium Octreotide and Gallium DOTATATE PET images in nine patients, with reference to detection sensitivity of number of lesions. The pre-therapy scans were also used for dosimetric calculations. Fourteen of these 39 patients further went ahead with Lu-DOTATATE therapy. RESULTS: All 39 patients demonstrated Lu-DOTATATE uptake in the disease sites seen on the contrast CT images. The uptake intensity was well comparable to Indium Octreotide and Gallium DOTATATE PET scans of all nine patients, with equally well-defined lesions. The post-therapy Lu-DOTATATE scans of the 14 patients who underwent therapy demonstrated higher intensity uptake pattern in the same disease sites, suggesting favorable therapeutic effect. The scans were useful in determining dosimetric details for therapeutic purpose and adequate exposure rates to suggest good ablative effect. CONCLUSION: Our preliminary data suggest that Lu-DOTATATE whole body scanning procedure is cost effective and equally sensitive as Gallium DOTATOC/NOC PET scan in pre-therapy setting of neuroendocrine tumors. The additional advantage of dosimetry calculations on this scanning procedure makes it more ideal to tailor therapies with more accuracy.