Introduction:

Xerostomia is a well-known complication after iodine-131 (¹³¹I) therapy for thyroid carcinoma. It is currently insufficiently understood how the dose and biodistribution of ¹³¹I relates to salivary gland toxicity, and whether this is consistent for all salivary glands within a single patient. Prostate-specific membrane antigen (PSMA) positron emission tomography/computed tomography (PET/CT) was recently introduced as a new tool to evaluate the relative loss of vital acinar cells in individual salivary glands. We aimed to assess gland-specific salivary gland toxicity after ¹³¹I-therapy using PSMA PET/CT.

Methods:

Five patients with differentiated thyroid cancer underwent [⁶⁸Ga]Ga-PSMA-11 PET/CT to evaluate their eligibility for peptide radioligand therapy with [¹⁷⁷Lu]Lu-PSMA-617. Uptake patterns in salivary glands were evaluated visually and quantitatively as an indicator of vital acinar cell loss after prior ¹³¹I-therapy.

Results:

Four of 5 patients demonstrated significant lowered uptake in at least one salivary gland, after receiving at least 2 ¹³¹I-treatments. Asymmetric loss of vital acinar cells occurred by gland type (parotid/submandibular) and location (right/left). The other salivary glands in these patients and all salivary glands in the fifth patient showed normal uptake, demonstrating high intrapatient and interpatient variability.

Conclusions:

¹³¹I-therapy can induce salivary gland toxicity with high inter- but also high intrapatient variation among separate gland locations, which can be assessed with PSMA PET/CT. This new technique offers potential to guide further development and evaluation of protective measures in patients receiving ¹³¹I-therapy.

中文翻译：

---

PSMA PET / CT可以从碘131治疗中识别出患者唾液腺毒性的变异。

介绍：

口腔干燥症是碘131（¹³¹ I）治疗甲状腺癌后的众所周知的并发症。目前尚不充分了解¹³¹ I的剂量和生物分布与唾液腺毒性之间的关系，以及对于单个患者中所有唾液腺是否一致。最近引入了前列腺特异性膜抗原（PSMA）正电子发射断层扫描/计算机断层扫描（PET / CT）作为评估个体唾液腺中重要腺泡细胞相对损失的新工具。我们旨在评估使用PSMA PET / CT进行¹³¹ I治疗后特定腺体唾液腺的毒性。

方法：

对5例分化型甲状腺癌患者进行了[ ⁶⁸ Ga] Ga-PSMA-11 PET / CT，以评估他们接受[ ¹⁷⁷ Lu] Lu-PSMA-617进行肽放射配体治疗的资格。视觉和定量评估唾液腺的摄取模式，作为先前¹³¹ I治疗后重要腺泡细胞损失的指标。

结果：

5名患者中有4^名在接受至少2 ¹³¹ I治疗后，至少一个唾液腺的摄取明显降低。腺泡类型（腮腺/下颌下颌）和位置（右/左）引起重要腺泡细胞的不对称损失。这些患者的其他唾液腺和第五位患者的所有唾液腺均显示正常摄取，表明患者内和患者间差异很大。

结论：

¹³¹ I治疗可以诱发唾液腺毒性，在不同的腺体部位之间存在较高的患者间差异，而且患者内部差异很大，可以使用PSMA PET / CT进行评估。这项新技术为指导接受¹³¹ I治疗的患者的进一步开发和评估保护措施提供了潜力。