PURPOSE: Minimally invasive interventional cancer therapy with drug-carrying lipid nanoparticles (ie, liposomes) via convection-enhanced delivery by an infusion pump can increase intratumoral drug concentration and retention while facilitating broad distribution throughout solid tumors. The authors investigated the utility of liposome-carrying β-emitting radionuclides to treat head and neck cancer by direct intratumoral infusion in nude rats. MATERIALS AND METHODS: Four groups of nude rats were subcutaneously inoculated with human tongue cancer cells. After tumors reached an average size of 1.6 cm3, the treatment group received an intratumoral infusion of liposomal rhenium-186 (186Re) (185 MBq [5 mCi]/cm3 tumor). Three control groups were intratumorally infused with unlabeled liposomes, unencapsulated 186Re-perrhenate, or unencapsulated intermediate 186Re compound (186Re-N,N-bis[2-mercaptoethyl]-N′, N′-diethyl-ethylenediamine [BMEDA]). In vivo distribution of 186Re activity was measured by planar γ-camera imaging. Tumor therapy and toxicity were assessed by tumor size, body weight, and hematology. RESULTS: Average tumor volume in the 186Re-liposome group on posttreatment day 14 decreased to 87.7% ± 20.1%, whereas tumor volumes increased to 395.0%514.4% on average in the other three groups (P<.001 vs 186Re-liposome). The 186Re-liposomes provided much higher intratumoral retention of 186Re activity, resulting in an average tumor radiation absorbed dose of 526.3 Gy ± 93.3, whereas 186Re-perrhenate and 186Re-BMEDA groups had only 3.3 Gy ± 1.2 and 13.4 Gy ± 9.2 tumor doses, respectively. No systemic toxicity was observed. CONCLUSIONS: Liposomal 186Re effectively treated head and neck cancer with minimal side effects after convection-enhanced interventional delivery. These results suggest the potential of liposomal 186Re for clinical application in interventional therapy of cancer.
- squamous cell carcinoma
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine