Inf J Radmt mn Oncology B!ol Php Vol 25. PP 3-7 0360-3016193 $6.00 + .OO Pnnted ,n the U.S.A. All rights reserved. Copyright 0 1992 Pergamon Press Ltd. ?? Clinical Original Contribution PREDICTIVE VALUE OF IN VITRO RADIOSENSITIVITY PARAMETERS IN HEAD AND NECK CANCERS AND CERVICAL CARCINOMAS: PRELIMINARY CORRELATIONS WITH LOCAL CONTROL AND OVERALL SURVIVAL T. GIRINSKY, M.D.,’ R. LUBIN, B.SC.,~ J. P. PIGNON, M.D.,2 N. CHAVAUDRA, M.SC.,~ J. GAZEAU, M.D.,’ B. DUBRAY, M.D.,’ J. M. COSSET, M.D.,’ G. SOCIE, M.D. AND B. FERTIL, PH.D.~ ‘Department of Radiotherapy, ‘Department of Biostatistics, 3Radiobiology Laboratory, Unit6 lnserm 247, Dr. E. P. Malaise; 4Department of Pathology, lnstitut Gustave-Roussy, Villejuif; and ‘Unit6 Inserm 194, H6pital PitiC Salp&ihe, Paris, France Purpose: To determine whether in vitro radiosensitivity parameters are predictive of treatment outcome. Methods and Materials: Biopsies were obtained from patients with head and neck cancers (57) and cervical carcinomas (20) and in vitro radiosensitivity parameters were obtained using the CAM plate assay. Results: In most cases (75%) patients were treated with radiation alone. The median follow up was 461 days. When the whole group of head and neck cancers and cervical carcinomas was considered, patients with a SF2 value below 0.36 had a higher 2-year local control rate (93% versus 68%) and a higher 2-year survival rate (71% vs. 62%) than those with SF2 values above that threshold, but differences were not significant. These trends persisted when head and neck cancers were considered alone with a higher local control rate (86% vs. 67%) and a higher survival rate (75% vs. 52.5%) obtained for patients with a SF2 value below 0.36. When the alpha value was evaluated for the whole group of patients a significantly higher local control rate (80.5% vs. 40.5%) and overall survival rate (71% versus 37.5%) at 2 years were obtained for patients with alpha values above 0.07 Gy-‘. When only the group of head and neck cancers was considered, local control rate was significantly higher (79% vs. 33%) but overall survival rate (65.5% vs. 33%) was not significantly higher for alpha values above 0.07 Gy-‘. Conclusion: These results are encouraging but need to be confirmed with a larger number of patients with a longer follow-up. Predictive assays, Intrinsic, Radiosensitivity, Local control, Overall survival, Head and neck cancer, Uterine cervix carcinoma, Radiation treatment. INTRODUCTION Treatment outcome for head and neck cancers and cer- vital carcinomas can be correlated with a number of clin- ical factors such as clinical performance status, primary site, T and N stages. Identification of biological factors that are independent of the known clinical prognostic fac- tors might help better predict tumor response to treatment. This could lead to an improved definition of treatment strategies and possibly to a higher locoregional control and higher overall survival. Fertil and Malaise (7) and Deacon et al. (6) suggested that intrinsic radiosensitivity of tumor cells measured by the surviving fraction at 2 Gy (SF,) could play a critical role in tumor response to ra- diation treatment. Intrinsic radiosensitivity can be deter- mined using either a clonogenic assay (9) or a mass culture assay (2). Preliminary correlations between the SF2 and local control in patients with head and neck cancers treated with surgery and post operative radiotherapy were disappointing (4). On the other hand, correlations between SF2 values and local control in cervical carcinomas treated with radiation only were extremely encouraging (10). We present our experience with head and neck cancers and cervical carcinomas mostly treated with radiation alone. METHODS AND MATERIALS Materials Biopsy specimens were obtained from patients during clinical examination under general anesthesia and prior to any treatment. Reprint requests to: T. Girinsky, Department of Radiotherapy, lnstitut Gustave-Roussy, Villejuif, 94805, France. Acknowledgements-We are grateful to Dr. E. P. Malaise for fruitful discussions, to Lorna Saint Ange and Penelope Frazee for assistance in revising the manuscript and to Josiane Le Cadre and Marion Catelain in preparing the manuscript. This work was supported by grants from the Gustave Roussy Institute (89 D 1 l), Ligue FranCaise contre le Cancer de 1’Essonne and from the Association pour la Recherche sur le Cancer (ARC 6804). Accepted for publication 24 July 1992. 3