Long-term survival and toxicity in patients with neuroendocrine tumors treated with 177 Lu-octreotate peptide radionuclide therapy.

BACKGROUND: Peptide receptor radionuclide therapy (PRRT) has shown favorable results in neuroendocrine tumors (NETs). Long-term safety and efficacy data for 177 Lu-octreotate PRRT, particularly in combination with chemotherapy, is lacking. METHODS: The authors conducted a retrospective review of the long-term toxicity and survival outcomes of 104 patients with advanced NETs treated on 4 phase 2 clinical trials with Lutetium-177-octreotate (177 Lu-octreotate) PRRT, mostly in combination with chemotherapy. Median follow-up was 68 months, which represents the longest follow-up study of 177 Lu-octreotate PRRT for NETs to date. RESULTS: Median progression-free survival (PFS) was 37 months, and median overall survival (OS) was 71 months. Five- and 10-year OS were 62% and 29%, and 5- and 10-year PFS were 36% and 21%, respectively, demonstrating 177 Lu-octreotate can provide durable responses. PRRT was well tolerated with 1.9% of patients developing chronic renal impairment and 1% of patients developing long-term thrombocytopenia. Interestingly, there was a relatively high rate of myelodysplasia (MDS)/leukemia (6.7%), possibly attributable to the longer follow-up (with all except 1 case occurring more than 4 years after PRRT treatment) or to the addition of concurrent chemotherapy. CONCLUSIONS: Lutetium-177-Octreotate PRRT remains an efficacious and well tolerated treatment in long-term follow-up. For clinicians deciding on the timing of PRRT for individual patients, the 6.7% long-term risk of MDS/leukemia needs to be balanced against the 21% PFS at 10 years.

Outpatient 131I-rituximab radioimmunotherapy for non-Hodgkin lymphoma: a study in safety.

PURPOSE: This study aimed to establish the safety of outpatient 131I-rituximab radioimmunotherapy by measuring the radiation exposure of hospital staff, carers, and members of the public and by estimating the environmental impact of radioactive urinary excretion. METHODS: Two hundred consecutive outpatients treated with 131I-rituximab radioimmunotherapy of non-Hodgkin lymphoma (NHL) with therapeutic activities between 1 and 4.5 GBq (mean, 2.3 GBq; or between 27 and 121 mCi; mean, 62 mCi) predicated on a prescribed whole-body radiation-absorbed dose of 0.75 Gy were studied. Their 279 family members/carers and 432 visitors wore thermoluminescent dosimeter badges for the week during which the patients were confined to their home after treatment. RESULTS: All 200 patients received 131I-rituximab activities according to the prescribed dose of 0.75 Gy to the whole body. From 200 consecutive patients, over the 7 days after therapy, mean radiation exposure of adult carers was 0.49 mSv (range, <0.01 to 3.67 mSv). To other coresiding family members, mean exposure was 0.23 mSv (range, <0.01 to 1.20 mSv), and for visitors sharing badges, the mean exposure was 0.17 mSv (range, <0.01 to 0.73 mSv). Urinary activity excreted over the week after 131I-rituximab therapy was typically less than 25% of the administered activity. CONCLUSIONS: 131I-rituximab radioimmunotherapy for non-Hodgkin lymphoma may be safely administered on an outpatient basis. The median radiation exposure of carers, cohabitants of the patient, and visitors is well within the limits recommended by international guidelines. Local regulatory agency-designated patient release rate limit of less than 25 µSv/h at 1 m was attained within 1 week of therapeutic 131I-rituximab administration.