PT - JOURNAL ARTICLE AU - Machaba Sathekge AU - Otto Knoesen AU - Frank Bruchertseifer AU - Florette Reyneke AU - Clemens Kratochwil AU - Thabo Lengana AU - Frederik Giesel AU - Ismaheel Lawal AU - Gill BOSHOMANE AU - Mariza Vorster AU - Alfred Morgenstern TI - <strong>Initial experience with <sup>225</sup>Ac-PSMA-617 in patients with advanced-stage prostate cancer</strong> DP - 2018 May 01 TA - Journal of Nuclear Medicine PG - 528--528 VI - 59 IP - supplement 1 4099 - http://jnm.snmjournals.org/content/59/supplement_1/528.short 4100 - http://jnm.snmjournals.org/content/59/supplement_1/528.full SO - J Nucl Med2018 May 01; 59 AB - 528Objectives: To date, targeted α-therapy with 225Ac-PSMA-617 although still preliminary, has demonstrated strong potential to significantly benefit advanced-stage prostate cancer patients. Here we report our initial experience with 225Ac-PSMA-617 in a developing country, as one of the first groups to provide this therapy. Methods: Eligible patients with confirmed advanced-stage prostate cancer were recruited and treated with standardized activities of 8 MBq 225Ac-PSMA-617 in two month intervals. In case of favorable responses activities were decreased to 6 MBq or 4 MBq in subsequent cycles to minimize toxicity. Baseline imaging and follow-up were performed with 68Ga-PSMA-11 PET/CT prior to the next treatment cycle. Interim treatment response evaluation was based on the radiologic response, tumor marker and functional results. Results: Twenty-five patients with a mean age of 66 years were treated. A treatment activity of 8 MBq exhibited moderate toxicity with grade I-II of xerostomia in 28% of patients and induced significant antitumor response in these high-tumor-burden patients. Remarkable antitumor activity by means of objective radiologic response or tumor marker decline was observed in 85% evaluable patients. Our short-term results also demonstrate a favourable hematological and renal toxicity profile and quality of life improvements. Conclusion: Standard treatment with 8 MBq 225Ac-PSMA617 every two months seems to be clinically safe with biochemical response and imaging response in around 85% of patients along with xerostomia in 28% of patients as the notable side effect. A larger multicenter trial is needed to confirm our preliminary results which are currently limited by short follow-up and small sample size.