RadioLigand Therapy with [ 177 Lu]Lu-PSMA-617 for Salivary Gland Cancers: Literature Review and First Compassionate Use in France.

Salivary gland cancers are rare tumors comprising a large group of heterogeneous tumors with variable prognosis. Their therapeutic management at a metastatic stage is challenging due to the lack of therapeutic lines and the toxicity of treatments. [ 177 Lu]Lu-PSMA-617 (prostate-specific membrane antigen) is a vectored radioligand therapy (RLT) initially developed to treat castration-resistant metastatic prostate cancer with encouraging results in terms of efficacy and toxicity. Many malignant cells could be treated with [ 177 Lu]Lu-PSMA-617 as long as they express PSMA as a consequence of androgenic pathway activation. RLT may be used when anti-androgen hormonal treatment has failed, particularly in prostate cancer. [ 177 Lu]Lu-PSMA-617 has been proposed in certain salivary gland cancers, though the expression of PSMA is demonstrated by a significant uptake using [ 68 Ga]Ga-PSMA-11 PET scan. This theranostic approach could be a new therapeutic option, warranting prospective investigation in a larger cohort. We review the literature on this subject and offer a clinical illustration of compassionate use in France as a perspective for administering [ 177 Lu]Lu-PSMA-617 in salivary gland cancer.