Nuklearmedizin-nuclear Medicine最新文献

Aim: Our aim was to test the assertion that in terms of rate or severity level, adverse events (AEs) after fine-needle aspiration biopsies (FNABs) of thyroid nodules are unfazed by daily low-dose (100 mg) aspirin (acetylsalicylic acid, ASA) intake.

Methods: We selected 268 patients for study, grouped as ASA-treated (P_ASA, n=78) or control (P_Ctrl, n=190) subjects. Controls received no antithrombotic medication. AE rates and severities were then analyzed based on patient- and nodule-related factors. We also compared group rates of non-diagnostic cytology results.

Results: AEs arising after FNABs (P_ASA, 5%; P_Ctrl, 8%) did not differ significantly by group in rate (p=0.4873) or severity level (p=0.3399). All were classifiable as minor incidents, none warranting any intervention.

Conclusions: The data from the present study suggest, AEs after FNABs of thyroid nodules seldom occur and qualify as minor incidents. Such procedures may be safely conducted in patients taking daily low-dose ASA. There is no evidence to support preemptive therapeutic withdrawal.

PSMA-PET/CT for imaging prostate cancer (PC) has spread worldwide since its clinical introduction in 2011. The majority of experiences have been collected for PSMA-PET-imaging of recurrent PC. Data for primary staging of high-risk PC are highly promising. Meanwhile, a plethora of PSMA-ligands are available for clinical use (e. g. ⁶⁸Ga-PSMA-11, ⁶⁸Ga-PSMA-I&T, ⁶⁸Ga-PSMA-617, ¹⁸F-DCFBC, ¹⁸F-DCFPyL, ¹⁸F-PSMA-1007, ¹⁸F-rhPSMA-7 and ¹⁸F-JK-PSMA-7). However, an official approval is available only for ⁶⁸Ga-PSMA-11 (approved by the US FDA in 2020) and ¹⁸F-DCFPyL (approved by the US FDA in 2021).Recommendations for acquisition times vary from 1-2 h p. i. It has been shown that for the majority of tumour lesions, the contrast in PSMA-PET/CT increases with time. Therefore, additional late imaging can help to clarify unclear findings. PSMA-PET/CT should be performed prior to commencing an androgen deprivation therapy (ADT) since (long term) ADT reduces the visibility of PC lesions. Following injection of PSMA-ligands, hydration and forced diuresis are recommended for PSMA-ligands with primarily excretion via the kidneys in order to increase the visibility of tumour lesions adjacent to the urinary bladder.PSMA-ligands are physiologically taken up in multiple normal organs. For some ¹⁸F-labelled PSMA-ligands, presence of unspecific focal bone uptake has been reported. When using these tracers, focal bone uptake without CT-correlate should be interpreted with great caution. Besides prostate cancer, practically all solid tumors express PSMA in their neovasculature thereby taking up PSMA-ligands, although usually at a lower extent compared to PC. Also multiple benign lesions and inflammatory processes (e. g. lymph nodes) take up PSMA-ligands, also usually at lower extent compared to PC.

Purpose: To compare bone marrow biopsy (BMB) with [18F]-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (PET/CT) imaging in the demonstration of bone marrow involvement in children with Hodgkin's Lymphoma (HL) and to investigate the effectiveness of PET/CT imaging and thus the necessity for BMB at staging.

Methods: Pediatric patients with HL, who underwent both bilateral iliac BMB and PET/CT imaging at disease staging were retrospectively analyzed. In determining bone marrow involvement (BMinv), BMB and/or first/follow-up PET/CT imaging were eligible for review.

Results: Fifty-six patients were included. BMinv was detected by PET/CT imaging in 6/56 (10.7%), whereas the proportion was 3/56 (5.3%) in BMB specimens. Bone marrow biopsies and PET/CT images were concordant in 53/56 (94.6%) patients with BMB specimens missing three cases of BMinv detected by PET/CT. When diagnostic accuracy was calculated, sensitivity, specificity, positive predictive value and negative predictive values for PET/CT were 100%, 100%, 100%, 100%, respectively, and the same values for BMB were 50%, 100%, 100%, 94.3%, respectively.

Conclusions: The results of PET/CT and BMB for staging of pediatric HL patients were compatible, and PET/CT imaging was found to provide high diagnostic performance in determining BMinv. In keeping with earlier research, the current study showed that BMB may not be necessary in every patient at staging, and should be reserved for cases where PET/CT is inconclusive.

Introduction: In breastfeeding women, the indication for scintigraphic imaging is strongly restricted due to potential transition of the radiopharmaceutical to the child via breast milk. The potential activity uptake of the breastfed child depends on the chemical compound of the radio pharmaceutical as well as biokinetics and metabolism in the maternal body.

Methods: In the presented case ^99mTc-MIBI scintigraphy was performed in a breastfeeding woman with sonographically suspicious thyroid nodules. Breastfeeding was interrupted for 30 hours and the breast milk during this period was collected and analysed to determine the excreted activity and the potentially resulting dose to the breastfed child.

Results: Activity concentration in the first breast milk sample (1.83 hours after administration of 500 MBq ^99mTc-MIBI) was 380 Bq/mL, resulting in an absolute activity of 50 kBq for a sample size of 132 mL. Subsequently activity concentration decreased to 6 Bq/mL (29.8 hours p.i.). The calculated effective half-life of the secretion of ^99mTc-MIBI via breast milk was 4.7 hours. The potentially resulting effective dose for the breastfed child was 13.4 µSv (ICRP80: dose coefficient: 0.13 mSv/MBq for ^99mTc).

Conclusion: Time activity curve showed a rapid decrease of the ^99mTc-MIBI activity secreted to the breast milk. More than 90 % of the total secreted activity is attributable to the first 12 hours after administration. Therefore, an interruption of breastfeeding of 24 hours seems to be adequate.