The evolving role of targeted radioligand therapy in small cell and non-small cell lung cancer: a systematic review

Background: Targeted radioligand therapy (TRT) is an emerging theranostic modality in oncology. While well established in neuroendocrine and prostate cancers, its role in small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) remains investigational. This systematic review summarizes current evidence evaluating TRT in lung cancer. Methods: A Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)-guided systematic review of PubMed, Embase, and Scopus (2000–November 2025) was conducted. Original studies evaluating TRT in SCLC or NSCLC were included. Primary outcomes were tumor response, disease-control rate, and treatment-related toxicity. Secondary outcomes included progression-free survival, overall survival, and dosimetry. Risk of bias was assessed using the Risk Of Bias In Non-randomized Studies—of Interventions (ROBINS-I) tool. Results: From 2,453 records, 15 studies were included, reporting 358 lung cancer patients, of whom 105 received TRT. Disease-control rates reached up to 78% in mixed NSCLC/SCLC cohorts. In SCLC, somatostatin receptor-targeted peptide receptor radionuclide therapy demonstrated heterogeneous disease control (0–50%), with 177LuLu-labeled agents showing more favorable outcomes than 90YY-based therapy. The most favorable outcomes were a median progression-free survival of 11.9 months and an overall survival of 16 months in responders. In NSCLC, fibroblast activation protein (FAP)-targeted agents such as 177LuLu-FAP-2286 demonstrated partial metabolic responses, including a 44.4% response rate and 78% disease control in a mixed cohort. Severe toxicities were infrequent. Discussion: TRT is a promising but experimental option for advanced lung cancer. Early efficacy signals exist for strong somatostatin receptor (SSTR)-targeted therapy in SCLC and FAP-targeted therapy in NSCLC, but evidence remains limited. Prospective trials with standardized protocols and dosimetry are needed to define TRT’s role in lung cancer treatment.