PT - JOURNAL ARTICLE AU - Matthew Thorpe AU - Ari Kane AU - Jorge Oldan AU - Salvador Borges-Neto TI - Improved survival in 211 patients with stage IV carcinoid tumor treated with high dose I-131 MIBG is predicted by response at initial follow up and by multiple rounds of I-131 MIBG. DP - 2016 May 01 TA - Journal of Nuclear Medicine PG - 469--469 VI - 57 IP - supplement 2 4099 - http://jnm.snmjournals.org/content/57/supplement_2/469.short 4100 - http://jnm.snmjournals.org/content/57/supplement_2/469.full SO - J Nucl Med2016 May 01; 57 AB - 469Objectives Knowledge of survivorship and progression in carcinoid tumor patients treated with high dose iodine-131-meta-iodobenzylguanidine (MIBG) has been limited by small cohorts and short follow up intervals. We report response and progression-free survival in a cohort of n=211 carcinoid tumor patients treated with palliative 131I-MIBG between 1991 and 2014, mean follow up of 39 months, total of 685 person-years follow-up.Methods Retrospective chart review of a registry of patients receiving median dose 18,500 MBq (500 mCi) 131I-MIBG at an academic tertiary referral center. Imaging response (n=158) was assessed via Response Evaluation Criteria In Solid Tumors (RECIST) version 1.1 where imaging was available (n=76) or by official CT report (n=82) where images were not available for review. Symptomatic response (n=143) was assessed via chart review of clinical encounters with the oncology service. Lab response (n=60) was assessed by a 20% change in 2 consecutive values from baseline in either 5HIAA or chromogranin A. 19% of patients received additional subsequent rounds of 131I-MIBG.Results At first follow up, 71% of patients reported improvement in pre-treatment symptoms, primarily reduction in GI symptoms (diarrhea, nausea or vomiting, 80%), fatigue (40%), flushing (32%), and pain (28%). 33% experienced no symptomatic progression through follow-up; median time to symptomatic progression was 1.4y ± SE 0.3. Initial follow up imaging demonstrated 2% complete response, 18% partial response, 60% stability and 20% progression. 43% of patients showed no post MIBG imaging progression with median time to progression 1.7y ± 0.2. 34% of patients demonstrated lab response and 48% were stable on initial lab follow up. 43% of patients remained without lab progression throughout follow-up, with median time to laboratory progression 2.5y ± 0.5. Overall median survival from time of diagnosis was 6.3y ± 0.5, with 5, 10 and 20 year survival of 59, 31 and 10%. Median survival post diagnosis of metastatic disease was 5y ± 0.5. Survival post treatment was 2.4y ± 0.2. Improved survival was predicted by the following: a) multiple MIBG treatments vs. one treatment (4.0y ± 0.5 vs. 2.0y ± 0.3, p<0.05); b) stable / response vs. progression at first imaging follow up (4.0y ± 0.4 vs. 1.3y ± 0.3, p<0.001); c) symptomatic response vs. non-response to MIBG (4.2y ± 0.4 vs. 1.7y ± 0.6, p<0.001); d) response / stability vs. progression in labs (6.2y ± 1.5 vs. 2.9y ± 1.6, p<0.05).Conclusions Initial imaging, symptomatic and laboratory response to high dose 131I-MIBG predict long term outcomes in a large cohort with stage IV carcinoid tumor. Stratification by these factors may provide clinical advantage in post therapy clinical decision making by oncologists, radiologists and patients. Multiple rounds of MIBG therapy was also associated with prolonged survival, which may also be valuable to inform the management of stage IV carcinoid.