Predicting Hematologic Toxicity After [177Lu]Lu-DOTA-TATE Therapy in Patients with Neuroendocrine Tumors Using Clinical and PET Imaging Parameters: A Two-center Study

Purpose Hematologic toxicity is the most common adverse effect leading to treatment delay or early discontinuation of [¹⁷⁷Lu]Lu-DOTA-TATE peptide receptor radionuclide therapy (PRRT). We evaluated baseline clinical, laboratory, and quantitative somatostatin receptor (SSTR)-PET parameters as predictors of hematologic toxicity in gastroenteropancreatic neuroendocrine tumors (GEP-NETs), focusing on whether imaging adds value beyond routinely available clinical and laboratory data. Methods In this two-center retrospective study, 96 patients treated with 1–4 cycles of [¹⁷⁷Lu]Lu-DOTA-TATE PRRT were analyzed. Hematologic toxicity was defined as CTCAE grade aggravation from baseline using nadir complete blood count (CBC) values. Baseline clinical, hematologic, and [⁶⁸Ga]Ga-DOTA-TOC PET parameters were evaluated using univariable analyses, followed by multivariable logistic regression for grade ≥ 3 hematologic toxicity. Results Grade ≥ 3 hematologic toxicity affecting at least one hematologic parameter occurred in 20 patients (20.8%). Poorer baseline hematologic status, reflected by higher baseline hematologic grades and lower corresponding blood values, was associated with grade ≥ 3 toxicity. Greater prior PRRT exposure was also associated with increased grade ≥ 3 toxicity. In multivariable analysis, higher baseline platelet grade (OR, 6.64; 95% CI, 1.72–30.36; P = 0.0091) and a greater number of prior PRRT cycles (OR, 1.38; 95% CI, 1.03–1.86; P = 0.030) remained independently associated with grade ≥ 3 hematologic toxicity. Baseline PET parameters showed no consistent associations with hematologic toxicity. Conclusion Baseline hematologic status and prior PRRT exposure may help identify patients at increased risk of severe hematologic toxicity, whereas the baseline SSTR-PET parameters evaluated did not provide additional predictive value beyond clinical and hematologic data.