Radiofrequency Heat-Enhanced Direct Intratumoral Chemotherapy Of Prostate Cancer

ObjectTo investigate the possibility of using radiofrequency heat (RFH) to enhance direct intratumoral chemotherapy of prostate cancers.Material and MethodsThis study included two components:(i) in-vitro confirmation experiments using human prostate cancer (HPC) cells; and (ii) in-vivo validation experiments using animal models with HPC xenografts. For both in-vitro and in-vivo experiments, we set four different treatment groups, including (1) no treatment (control); (2) RFH-only; (3) chemotherapy (docetaxel)-only; and (4) combination therapy with both docetaxel and RFH (n=6 per group). For in-vitro experiments, HPC cell proliferation was measured using MTS colorimetry. For in-vivo experiments, we used magnetic resonance imaging (MRI) to follow up the changes of tumor sizes and tumor responses to different treatments overtime. MRI findings were confirmed by subsequent pathological correlation. ResultOf the in-vitro experiment, combination therapy caused significant decrease of HPC cell proliferation, compared to other three groups (P< 0.05). Of the in-vivo experiment, follow-up MRI demonstrated a significant reduction of the average tumor size in animals treated with combination therapy, compared to those receiving other treatments (P< 0.05). These results were well confirmed by pathological examination.ConclusionThis study confirms that RFH can enhance the therapeutic efficiency of docetaxel on prostate cancers, which thus has established the groundwork for further development of a new image-guidedlocal treatment of prostate cancers by simultaneous integration of RFH mediated by RFA and direct intra-tumoral chemotherapy to further eradicate tumor cells in tumor boundary.