title: Favorable Response of Metastatic Merkel Cell Carcinoma to Targeted 177Lu-DOTATATE Therapy: Will PRRT Evolve to Become an Important Approach in Receptor-Positive Cases?
abstract: This report illustrates an excellent partial response of Merkel cell carcinoma with multiple bilobar hepatic metastases to a single cycle of peptide receptor radionuclide therapy (PRRT) with (177)Lu-DOTATATE. This response, coupled with minimal side effects, warrants consideration of this therapy early in the disease course (rather than at an advanced stage after failure of other therapies) if the metastatic lesions exhibit adequate tracer avidity on somatostatin receptor-based imaging. Our patient showed progression of systemic disease after having undergone a second surgery and adjuvant radiotherapy to the head and neck, as well as chemotherapy, and hence was considered a candidate for PRRT. In a pretreatment study, the metastatic lesions demonstrated avidity to both somatostatin receptors and (18)F-FDG. Three months after the first cycle of treatment, when the patient was being evaluated for a second cycle, both imaging parameters showed evidence of a partial response that included nearly complete resolution of the two previously seen lesions. In view of the relatively good tolerability, minimal side effects, and targeted nature of the treatment, PRRT may evolve to become the first-line therapy for metastatic Merkel cell carcinoma and should be examined further in a larger number of patients.
authors.affiliation: Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Hospital Annexe, Mumbai, India drsanb@yahoo.com.
authors.forename: Sandip
authors.initials: S
authors.lastname: Basu
authors.affiliation: Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Hospital Annexe, Mumbai, India.
authors.forename: Rohit
authors.initials: R
authors.lastname: Ranade
mesh_terms: D015266:Carcinoma, Merkel Cell / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D058990:Molecular Targeted Therapy; D009362:Neoplasm Metastasis; D015282:Octreotide / Q000031:analogs & derivatives* / Q000378:metabolism / Q000627:therapeutic use; D009942:Organometallic Compounds / Q000378:metabolism / Q000627:therapeutic use*; D049268:Positron-Emission Tomography; D018000:Receptors, Peptide / Q000378:metabolism*; D012878:Skin Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D016896:Treatment Outcome
chemical_list: D009942:Organometallic Compounds; D018000:Receptors, Peptide; C447941:lutetium Lu 177 dotatate; D015282:Octreotide
keywords: 177Lu-DOTATATE; Merkel cell carcinoma; PRRT; peptide receptor radionuclide therapy