Y-90-DOTA-Phe1-Tyr3-Octreotide (90Y-
SMT 487,
OctreoTher) has shown potential for effectively treating patients with
neuroendocrine tumors. The dose-limiting organ for this agent is the kidney. The purpose of this work is to assess the effectiveness of a commercially available
amino acid solution on reducing renal uptake of 90Y-SMT 487 and determine the safety profile of this
solution. Subjects with
In-111 pentetreotide positive
tumors and normal
creatinine levels were treated with 3 cycles of 90Y-SMT 487, 120 mCi/cycle, at 6-9 week intervals. During each treatment two liters of an
amino acid solution containing
arginine and
lysine (
Aminosyn II 7%, Abbott Laboratories, Abbott Park, IL) were infused IV over 4 hours. Adverse events were recorded. To assess the effect of
Aminosyn II on renal uptake of 90Y-SMT 487, a subgroup of subjects underwent bremsstrahlung imaging 24 hours following infusion. Kidney to liver (K/L) count density ratios were generated from the baseline
In-111 pentetreotide images (performed without
amino acid infusion) and the 90Y bremsstrahlung images. Follow-up
creatinine levels were obtained. Thirty-seven subjects received a total of 89 90Y-SMT 487 treatments. The number of
amino-acid infusions associated with one or more episodes of
emesis was 53 (62%). During 13 (15%) of these infusions, the
Aminosyn II rate had to be reduced because of severe
nausea and
vomiting. Symptomatic
flushing occurred during 16 (18%) of the infusions. One subject experienced a near syncopal event shortly after completing the infusion.
Creatinine levels remained normal in 34 of 36 subjects during a mean follow-up period of 9.8 months. Fourteen subjects underwent bremsstrahlung imaging following infusion of 90Y-SMT 487. Kidney uptake appeared to decrease with administration of the
amino acid solution in 13 of 14 subjects. For the 28 individual kidneys, the mean percent decrease in the Kidney/Liver uptake ratio with the
amino acid solution was found to be 32%. We conclude that 2 L of
Aminosyn II 7% infused over 4 hours appears to notably reduce renal uptake of 90Y-SMT 487.
Aminosyn is generally well tolerated, particularly at lower infusion rates with occasional moderate to severe
nausea and
vomiting at higher rates.