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Corde S, Joubert A, Adam JF, Charvet AM, Le Bas JF, Estève F, Elleaume H, Balosso J. Synchrotron radiation-based experimental determination of the optimal energy for cell radiotoxicity enhancement following photoelectric effect on stable iodinated compounds. Br J Cancer 2004; 91:544-51. [PMID: 15266326 PMCID: PMC2409846 DOI: 10.1038/sj.bjc.6601951] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
This study was designed to experimentally evaluate the optimal X-ray energy for increasing the radiation energy absorbed in tumours loaded with iodinated compounds, using the photoelectric effect. SQ20B human cells were irradiated with synchrotron monochromatic beam tuned at 32.8, 33.5, 50 and 70 keV. Two cell treatments were compared to the control: cells suspended in 10 mg ml−1 of iodine radiological contrast agent or cells pre-exposed with 10 μM of iodo-desoxyuridine (IUdR) for 48 h. Our radiobiological end point was clonogenic cell survival. Cells irradiated with both iodine compounds exhibited a radiation sensitisation enhancement. Moreover, it was energy dependent, with a maximum at 50 keV. At this energy, the sensitisation calculated at 10% survival was equal to 2.03 for cells suspended in iodinated contrast agent and 2.60 for IUdR. Cells pretreated with IUdR had higher sensitisation factors over the energy range than for those suspended in iodine contrast agent. Also, their survival curves presented no shoulder, suggesting complex lethal damages from Auger electrons. Our results confirm the existence of the 50 keV energy optimum for a binary therapeutic irradiation based on the presence of stable iodine in tumours and an external irradiation. Monochromatic synchrotron radiotherapy concept is hence proposed for increasing the differential effect between healthy and cancerous tissue irradiation.
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Affiliation(s)
- S Corde
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - A Joubert
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - J F Adam
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - A M Charvet
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - J F Le Bas
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
- Unité IRM, service de Neuroradiologie, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - F Estève
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
- Unité IRM, service de Neuroradiologie, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - H Elleaume
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
- IFR no. 1 ‘RMN biomédicale, de la cellule à l'homme’, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
| | - J Balosso
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
- Département de Cancérologie et d'Hématologie, Service de Radiothérapie, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France
- INSERM U647 ‘Rayonnement Synchrotron et Recherche Médicale’, Université Joseph Fourier & ID17 Biomedical Beamline of European Synchrotron Radiation Facility, CHU A Michallon, BP 217, 38043 Grenoble Cedex 09, France. E-mail:
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