[IN-111-DTPA-D-PHE(1)]-OCTREOTIDE SCINTIGRAPHY IN PATIENTS WITH HORMONE-REFRACTORY PROSTATIC ADENOCARCINOMA CAN PREDICT THERAPY OUTCOME WITH OCTREOTIDE TREATMENT - A PILOT-STUDY

A pilot study to evaluate the predictive value of Indium-111-labelled somatostatin analogue [DTPA-D-Phe(1)]octreotide scintigraphy (OctreoSc an111) in the Octreotide treatment of hormone-refractory prostatic ade nocarcinoma was initiated. Ten patients were investigated with OctreoS can111 with regard to disease extension and tumour-to-background ratio . Subsequently, the patients were treated with Octreotide (Sandoz; Bas el, Schweiz) at a dose of 100 mu g twice a day subcutaneously. Three p atients experied symptomatic relief, and two of these responded with a decrease in PSA. Three patients did not notice any difference after 6 months of treatment and two of them developed an increase in their PS A value. One patient progressed after five months as regards both PSA and symptoms. Three patients were not able to complete treatment. Of t he seven evaluable patients, the three with the highest tumour-to-back ground ratios at OctreoScan111 were those patients with reducted or st able PSA levels, and none of these progressed during treatment. Previo us reports along with this study demonstrate that only a minority of p atients with hormone-refractory prostatic adenocarcinoma benefit from Octreotide treatment. However, OctreoScan111 investigations may identi fy patients who will respond to Octreotide therapy.