PT - JOURNAL ARTICLE AU - Andreas Kluge AU - Richard Baum AU - Harshad Kulkarni AU - Karin Niepsch AU - Norman Bitterlich AU - Manal Sayeg AU - Ulrike Schorr-Neufing AU - Cees Van Echteld TI - Predictive value of baseline hematology parameters on outcome of <sup>177</sup>Lu-DOTATOC PRRT DP - 2016 May 01 TA - Journal of Nuclear Medicine PG - 1439--1439 VI - 57 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/57/supplement_2/1439.short 4100 - http://jnm.snmjournals.org/content/57/supplement_2/1439.full SO - J Nucl Med2016 May 01; 57 AB - 1439Objectives In external beam radiotherapy it has been well established that improved tissue oxygenation increases therapy efficacy, likely mediated by oxygen derived free radicals. Additionally, emerging evidence suggests immuno-stimulatory effects of radiotherapy through activation of lymphocytes. In peptide receptor radiotherapy (PRRT), the relevance of tissue oxygenation and immuno-stimulation have not been evaluated to date. Therefore, we compared baseline hematology parameters with PRRT efficacy.Methods After baseline hematology and laboratory evaluation, 56 patients with metastasized, progressive and DOTATOC uptake positive neuroendocrine tumors (NET) (50% gastroenteral, 26.8% pancreatic, 23.2% other primaries) were consecutively treated with 177Lu-DOTATOC and analyzed retrospectively. Patients received on average 2.1 (range 1 - 4) cycles of 177Lu-DOTATOC as 7.0 GBq (median) doses at 3-monthly intervals. Efficacy was analyzed based on RECIST and best response was classified as complete response (CR), partial response (PR), stable disease(SD) or progressive disease(PD) in relation to baseline hematology parameters.Results Hematology parameters are presented as mean ± standard deviation. The non-parametric Kruskal-Wallis test was used to detect significant differences. Post-hoc analysis with the least significant method was used to evaluate differences between groups. For all parameters with PKW &lt; 0.01, The PD group was significantly different from all other groups. View this table:Conclusions The significant positive correlations between PRRT outcome and both baseline hemoglobin content and baseline lymphocyte cell count are compatible with a cascade of free radical damage followed by immune activation. As the lymphocyte and neutrophil cell counts result from a differential white blood cell count, it is not surprising that we find an inverse correlation between PRRT outcome and neutrophil cell count. No correlation between PRRT outcome and leukocytes or platelets was found. Our results suggest that optimization of hemoglobin content prior to PRRT may be beneficial for therapy efficacy.