Intratumoral Injection of Holmium-Chitosan Complex in Prostate Cancer

Hong, Sung Hoo; Lee, Seung Ju; Kim, Sae Woong; Lee, Choong Bum; Kang, Seong Hak; Cho, Yong Hyun; Yoon, Moon Soo

Abstract

PURPOSE: The aim of this study was to pathologically evaluate the therapeutic and toxic effects of the 166Ho-chitosan complex(166HC) on prostatic cancer.
MATERIALS AND METHODS
The DU-145 cell line was subcutaneously heterotransplanted into 30 nude mice, resulting in 24 prostatic cancers. The 24 nude mice with prostatic cancer were divided into four groups. Group I(n=6) received 0.5ml normal saline, group II(n=6) 0.5ml chitosan, group III(n=6) 370 MBq of 166HC and group IV(n=6) 740 MBq of 166HC per 1cm3, intratumorally. The tumor sizes were measured at 1 and 2 weeks after injection. The 24 mice were sacrificed and pathological examination performed: Haematoxylin & Eosin(H & E) staining and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling(TUNEL) staining.
RESULTS
Two weeks after injection of 166HC, the tumor volumes in groups III and IV were smaller than those in groups I and II(p<0.05). H & E staining of the tumors showed wide central necrosis in groups III and IV, but not in groups I and II. TUNEL staining showed false positive reactions along the peripheral margins in all groups. No toxic changes were found in the liver, kidney, peripheral blood and bone marrow.
CONCLUSIONS
An intratumoral injection of 166HC appears to be a new, safe and promising alternative radiotherapeutic modality for the local control of prostatic cancer, with minimized toxicities as the administered 166HC is retained at the injection site.