Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Apr 11;29(5):241.
doi: 10.1007/s00784-025-06300-w.

Radioactivity levels in the saliva of patients undergoing targeted radioligand therapy with [177Lu]Lu-PSMA-I&T and [177Lu]Lu-DOTA-TOC

Christian Schedeit  1 , Nasir Gözlügöl  2 , Radi Saiyed Alsheikh  2 , Mohamed Shelan  3 , Robert Seifert  2 , Federico Caobelli  2 , Urs Borner  4 , Tateyuki Iizuka  1 , Benoît Schaller  1 , Axel Rominger  2 , Paul Cumming  2   5 , Ali Afshar-Oromieh  6 , Konstantinos G Zeimpekis  2
Affiliations

Radioactivity levels in the saliva of patients undergoing targeted radioligand therapy with [177Lu]Lu-PSMA-I&T and [177Lu]Lu-DOTA-TOC

Christian Schedeit et al. Clin Oral Investig. .

Abstract

Objectives: The number of patients receiving radioligand therapy (RLT) has risen sharply in recent years. This raises concerns about possible risks to dental healthcare workers due to their exposure to the patients and their saliva. We therefore set about to measure the salivary radioactivity in patients undergoing 177Lu-RLT.

Materials and methods: We recruited in-house RLT patients receiving [177Lu]Lu -DOTA-TOC (n = 6) or [177Lu]Lu-PSMA-I&T (n = 14). We measured the radioactivity concentrations in 1 ml saliva samples collected before and 0.5, 2, 4, 21, 27, and 45 h post application of the radioligands, with additional samples collected at 51 and 69 h for [177Lu]Lu-PSMA-I&T patients. The biological half-life (BHL) and area under the curve (AUC) were calculated for the radioactivity of the saliva for both cohorts.

Results: Both cohorts exhibited increases in salivary radioactivity, attaining peaks at 2 h p.i. of [177Lu]Lu-DOTA-TOC and 4 h p.i. of [177Lu]Lu-PSMA-I&T, and presenting with a significant decrease until the patients discharge. The median peak concentration for [177Lu]Lu-PSMA-I&T was four-fold higher than for the [177Lu]Lu-DOTA-TOC group. For PSMA-patients, the BHL was 14 h and the mean AUC was 895 kBqh/ml. For DOTA-TOC patients, these values were 8.5 h and 96 kBqh/ml, respectively.

Conclusion: Salivary radioactivity peaks earlier and at lower levels in [177Lu]Lu-DOTA-TOC patients compared to [177Lu]Lu-PSMA-I&T, which shows longer retention and ten times higher radioactivity turnover in saliva. However, radiation exposure to medical staff by the patents saliva can be considered minimal.

Clinical relevance: Salivary radioactivity of patients undergoing 177Lu-RLT poses minimal risk to oral healthcare workers.

Keywords: 177Lu-PSMA; MRONJ; PSMA; Prostate cancer; Radionuclide therapy; Saliva.

PubMed Disclaimer

Conflict of interest statement

Declarations. Disclosure: No potential conflict of interest relevant to this article was reported. Competing interests: The authors declare no competing interests.

Figures

Fig. 1
Fig. 1
Median salivary radioactivity concentrations (log10 kBq/ml) with corresponding interquartile range (IQR) bars, shown in logarithmic scale as a function of time post-application (p.a.) of [177Lu]Lu-DOTA-TOC (n = 6; orange curve) and [177Lu]Lu-PSMA-I&T (n = 14; blue curve)
Fig. 2
Fig. 2
Planar imaging of representative patients during RLT with (A) [177Lu]Lu-DOTA-TOC and (B) [177Lu]Lu-PSMA-I&T at 24 h post-application. The arrows indicate the non-uptake and uptake of the radiopharmaceutical in the salivary glands, respectively
See this image and copyright information in PMC

Similar articles

See all similar articles

References

    1. Fizazi K et al (2023) Health-related quality of life and pain outcomes with [(177)Lu]Lu-PSMA-617 plus standard of care versus standard of care in patients with metastatic castration-resistant prostate cancer (VISION): a multicentre, open-label, randomised, phase 3 trial. Lancet Oncol 24(6):597–610 - PMC - PubMed
    1. Parghane RV, Basu S (2023) PSMA-targeted radioligand therapy in prostate cancer: current status and future prospects. Expert Rev Anticancer Ther 23(9):959–975 - PubMed
    1. Kwekkeboom DJ et al (2010) Somatostatin-receptor-based imaging and therapy of gastroenteropancreatic neuroendocrine tumors. Endocr Relat Cancer 17(1):R53–73 - PubMed
    1. Khan S et al (2011) Quality of life in 265 patients with gastroenteropancreatic or bronchial neuroendocrine tumors treated with [177Lu-DOTA0,Tyr3]octreotate. J Nucl Med 52(9):1361–1368 - PubMed
    1. Bergsma H et al (2012) Peptide receptor radionuclide therapy (PRRT) for GEP-NETs. Best Pract Res Clin Gastroenterol 26(6):867–881 - PubMed