Gadolinium-Based Nanoparticles Sensitize Ovarian Peritoneal Carcinomatosis to Targeted Radionuclide Therapy

Ovarian cancer (OC) is the most lethal gynecologic malignancy (5-y overall survival rate, 46%). OC is generally detected when it has already spread to the peritoneal cavity (peritoneal carcinomatosis). This study investigated whether gadolinium-based nanoparticles (Gd-NPs) increase the efficacy of targeted radionuclide therapy using [177Lu]Lu-DOTA-trastuzumab (an antibody against human epidermal growth factor receptor 2). Gd-NPs have radiosensitizing effects in conventional external-beam radiotherapy and have been tested in clinical phase II trials. Methods: First, the optimal activity of [177Lu]Lu-DOTA-trastuzumab (10, 5, or 2.5 MBq) combined or not with 10 mg of Gd-NPs (single injection) was investigated in athymic mice bearing intraperitoneal OC cell (human epidermal growth factor receptor 2-positive) tumor xenografts. Next, the therapeutic efficacy and toxicity of 5 MBq of [177Lu]Lu-DOTA-trastuzumab with Gd-NPs (3 administration regimens) were evaluated. NaCl, trastuzumab plus Gd-NPs, and [177Lu]Lu-DOTA-trastuzumab alone were used as controls. Biodistribution and dosimetry were determined, and Monte Carlo simulation of energy deposits was performed. Lastly, Gd-NPs' subcellular localization and uptake, and the cytotoxic effects of the combination, were investigated in 3 cancer cell lines to obtain insights into the involved mechanisms. Results: The optimal [177Lu]Lu-DOTA-trastuzumab activity when combined with Gd-NPs was 5 MBq. Moreover, compared with [177Lu]Lu-DOTA-trastuzumab alone, the strongest therapeutic efficacy (tumor mass reduction) was obtained with 2 injections of 5 mg of Gd-NPs/d (separated by 6 h) at 24 and 72 h after injection of 5 MBq of [177Lu]Lu-DOTA-trastuzumab. In vitro experiments showed that Gd-NPs colocalized with lysosomes and that their radiosensitizing effect was mediated by oxidative stress and inhibited by deferiprone, an iron chelator. Exposure of Gd-NPs to 177Lu increased the Auger electron yield but not the absorbed dose. Conclusion: Targeted radionuclide therapy can be combined with Gd-NPs to increase the therapeutic effect and reduce the injected activities. As Gd-NPs are already used in the clinic, this combination could be a new therapeutic approach for patients with ovarian peritoneal carcinomatosis.

Evaluation of hepatic function after orthotopic liver transplantation: a comparative study using Belzer and Collins solutions

Belzer and Collins are solutions used in liver transplantation. The purpose of this study was to compare liver function after utilization of two different schemes of graft preservation using both solutions. Between December 2004 and September 2005, 43 liver transplantations were performed. Twenty-three of these used 2 L of Collins solution and 2 L of Belzer solution as the preservation solution. The others used three L of Collins and 1 L of Belzer solution as the preservation solution. The cold ischemia time of both groups was similar. We analyzed liver function using the serum ALT, AST, bilirubin and international normalized ratio. On the first day after the transplantation, the level of international normalized ratio of the group of patients that used 1 L of Belzer was significantly higher than the other group (P<.05). The levels of ALT, AST, and bilirubin were not different on day 7 after transplantation. We concluded that using only 1 L of Belzer solution is as efficient with the advantage that it is less expensive.