Effect Of Long-acting Somatostatin Analogue Research Articles

Changes in biodistribution on 68Ga-DOTA-Octreotate PET/CT after long acting somatostatin analogue therapy in neuroendocrine tumour patients may result in pseudoprogression

BackgroundTo evaluate the effects of long-acting somatostatin analogue (SSA) therapy on 68Ga-DOTA-octreotate (GaTate) uptake at physiological and metastatic sites in neuroendocrine tumour (NET) patients.MethodsTwenty-one patients who underwent GaTate PET/CT before and after commencement of SSA therapy were reviewed. Maximum standardized uptake values (SUVmax) were measured in normal organs. Changes in uptake of 49 metastatic lesions in 12 patients with stable disease were also compared. Serum chromogranin-A (CgA) levels were available for correlation between scans in 17/21 patients.ResultsMean thyroid, spleen and liver SUVmax decreased significantly following SSA therapy from a baseline of 5.9 to 3.5, 30.3 to 23.1 and 10.3 to 8.0, respectively (p = < 0.0001 for all). Pituitary SUVmax increased from 10.2 to 11.0 (p = 0.004) whereas adrenal and salivary gland SUVmax did not change. Tumour SUVmax increased in 7 of 12 patients with stable disease; CgA was stable or decreasing in 5 of these patients. 30/49 (61%) metastatic lesions had an increase in SUVmax and lesion-to-liver uptake ratio increased in 40/49 (82%) following SSA therapy.ConclusionLong-acting SSA therapy decreases GaTate uptake in the thyroid, spleen and liver but in most cases increases intensity of uptake within metastases. This has significant implications for interpretation of GaTate PET/CT following commencement of therapy as increased intensity alone may not represent true progression. Our findings also suggest pre-dosing with SSA prior to PRRT may enable higher doses to be delivered to tumour whilst decreasing dose to normal tissues.

Effects of long-acting somatostatin analog (SMS 201-995) on eicosanoid synthesis and survival in rats with acute necrotizing pancreatitis.

The effects of a long-acting somatostatin analog (SMS 201-995) were studied in an established model of acute necrotizing pancreatitis in rats. SMS 201-995, when given prior to induction of pancreatitis, decreased the mortality rate from 100% to 40% (P = 0.0001). When treatment was given after induction of pancreatitis, the mortality rate was 75% (P = 0.2). Administration of SMS 201-995 did not influence the serum concentrations of amylase markedly, but the lipase levels were significantly lowered (P less than 0.05). The low levels of serum insulin and the glucose level in whole blood were not influenced. The volume of ascitic fluid was reduced (P less than 0.01). Moreover, less peritoneal fat necrosis was seen, suggesting a reduction in toxic factors in the ascitic fluid. Treatment with SMS 201-995 prior to induction of pancreatitis caused a significant increase in the levels of circulating 6-keto-PGF1 alpha, the stable metabolite of prostaglandin I2 (P less than 0.01). The levels of thromboxane B2 and prostaglandin E2 did not change significantly. The present data support the hypothesis that SMS 201-995 is an activator of prostaglandin I2, thereby modifying the course of the disease.

The effect of long-acting somatostatin analogue on enzyme changes after endoscopic pancreatography

The effect of the long-acting somatostatin analogue, octreotide acetate (Sandostatin) on enzyme elevation after endoscopic pancreatography was studied in a prospective, randomized, double-blind trial. Sixty-three consecutive patients undergoing ERCP were randomly allocated to two group. In the control group, 34 patients received isotonic sodium-chloride, and in the treated group 29 patients received 0.1 mg of octreotide acetate subcutaneously before the pancreatography. After the endoscopy, amylase levels increased to pathological range in 15 of the controls and in 3 of the treated patients, whereas lipase levels showed a pathological rise in 17 of the controls and in 5 of the treated patients. A significant difference (p less than 0.01) was observed in the amylase and lipase changes between the two groups at 90 and 180 min after pancreatography. The enzyme levels showed at 90 min, mean +/- SD amylase: controls 540 +/- 185 units/liter, treated patients 261 +/- 108 units/liter; lipase: controls 304 +/- 98 units/liter, treated patients 198 +/- 88 units/liter. These findings suggest that the use of long-acting somatostatin analogue ameliorates the enzyme increases in the serum after endoscopic pancreatography.

Metabolic effects of long-acting somatostatin analogue (sandostatin) in type I diabetic patients on conventional therapy

Metabolic effects of long-acting somatostatin analogue (sandostatin) in type I diabetic patients on conventional therapy