In Vitro Demonstration of Synergy Between Radionuclide and Chemotherapy

• Published in: The Journal of nuclear medicine (1978) Vol. 39; no. 5; pp. 900 - 903
• Main Authors: Chenoufi, Norchen, Raoul, Jean-Luc, Lescoat, Gerard, Brissot, Pierre, Bourguet, Patrick
• Format: Journal Article
• Language: English
• Published: Reston, VA Soc Nuclear Med 01.05.1998; Society of Nuclear Medicine
• Subjects: Antineoplastic agents; Antineoplastic Combined Chemotherapy Protocols - therapeutic use; Biological and medical sciences; Cisplatin - administration & dosage; Combined Modality Therapy; Combined treatments (chemotherapy of immunotherapy associated with an other treatment); Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Doxorubicin - administration & dosage; Fluorouracil - administration & dosage; Hepatoblastoma - drug therapy; Hepatoblastoma - radiotherapy; Humans; In Vitro Techniques; Iodine Radioisotopes - therapeutic use; Liver Neoplasms - drug therapy; Liver Neoplasms - radiotherapy; Medical sciences; Pharmacology. Drug treatments; Radiation Tolerance; Time Factors; Tumor Cells, Cultured; Cell culture; Radiosensitivity; Toxicity; Radiotherapy; In vitro; Synergism; Dose activity relation; Time dependence; Chemotherapy; Combined treatment; Survival curve; Therapeutic role; Iodine
• ISSN: 0161-5505; 1535-5667

Radionuclide therapy is currently used in the treatment of some malignancies, including hepatocellular carcinoma. The effects of external beam radiotherapy are improved by combining it with chemotherapy. The aim of this study was to determine whether such a synergistic effect could be demonstrated in vitro with internal radiation therapy. HepG2 cells were cultured from Day 0 to Day 8 under the following conditions: exposure for 4 hr on Day 2 to increasing concentrations of 5-fluorouracil (5FU), doxorubicin or cisplatin (CDDP); exposure from Day 2 to Day 8 to increasing concentrations of 131-iodide; exposure on Day 2 to low-toxicity doses of drugs for 4 hr, followed by exposure to 131I at increasing concentrations; and exposure to increasing concentrations of 131I from Day 2 to Day 8, with exposure for 4 hr on Day 6 to the drugs. Cell toxicity was assessed by enzyme release (lactate dehydrogenase and aspartate aminotransferase) in the culture medium and on cell survival (protein and tetrazolium dye test). All cultures were run in triplicate. A dose- and time-dependent toxicity was demonstrated with doxorubicin and CDDP but not with 5FU. When HepG2 cells were exposed to 131I, the toxicity was rather low, but significant, and was time- and dose-dependent. Treating these cells with combination radiotherapy and chemotherapy resulted in a toxicity that was significantly greater than that with 131I or chemotherapy drugs alone. The radiosensitivity of HepG2 cells is low; combining a chemotherapeutic drug with a radiotherapeutic agent improves the radiosensitivity in a synergistic fashion. This combination is thus able to strengthen the therapeutic effect of internal radiation therapy in different malignancies, particularly in hepatocellular carcinoma.