PSMA-targeted imaging and radioligand therapy of advanced adenoid cystic carcinomas and other salivary gland carcinomas

Ziel/Aim: Adenoid cystic carcinomas (ACCs) and similar glandular tumors, while rare, are challenging malignancies often originating in the salivary glands, though they can also appear in other tissues, such as the breast, respiratory tract, or Bartholin glands. ACCs and other salivary gland carcinomas (SGCs) frequently exhibit high levels of PSMA expression, which has spurred interest in PSMA-targeted radioligand therapy (RLT) as a potential treatment. This study assessed the utility of PSMA PET imaging and the efficacy of PSMA RLT in patients with ACCs/SGCs.

Methodik/Methods: This study included ten patients with histologically confirmed ACC or SGC who underwent PSMA PET imaging and were scored using the PROMISE criteria. PET imaging was performed 75 min (± 15 min) after injection of [¹⁸F]PSMA-1007. Semiquantitative assessment of tracer uptake in PET was performed as follows: For tumor lesions SUVmax and SUVmean (using a 50% max. threshold) were measured on baseline PET scans. To reduce over-representation, a maximum of 5 lesions per organ site were analyzed in patients with multifocal or disseminated disease. Patients with a PROMISE score of≥2 were considered candidates for RLT. Of these, four patients received a total of nine RLT cycles, with a total amount of 68 GBq of [177Lu]-PSMA-I&T.

Ergebnisse/Results: PSMA expression scores for the ten patients were as follows: 0 (n=2), 1 (n=2), 2 (n=5), and 3 (n=1). Seven patients exhibited bone metastases, with a mean SUVmax of 12.3 (SD±3.1); seven had lung metastases (mean SUVmax: 5.8, SD±4.0); two had liver metastases (mean SUVmax: 9.6, SD±4.5); and three had lymph node metastases (mean SUVmax: 8.8, SD±2.3). Among the four patients who underwent RLT, three were evaluable for response: two exhibited progressive disease (PD), while one achieved stable disease (SD) after four cycles, with a progression-free survival (PFS) of 13 months.

Schlussfolgerungen/Conclusions: PSMA RLT was well-tolerated and demonstrated potential as a treatment option for patients with ACCs/SGCs. In this cohort, one patient achieved disease control for over one year. However, further research in larger studies is needed to enhance patient selection criteria and optimize outcomes.

Publikationsverlauf

Artikel online veröffentlicht:
12. März 2025