Intracavitary High Dose Rate Afterloading Therapy with Iridium-192: Basic Physical Measurements, Dosimetry, and Localisation

  • Norfried Thesen
Part of the Medical Radiology book series (MEDRAD)


The γ-ray emitting isotopes like radium 226, cobalt 60, iridium 192, and cesium 137 are used with intracavitary afterloading techniques. Though their physical parameters are quite different (Table 1), the isodose distribution does not change very much if therapy-relevant distances of 1–5 cm are respected. The dose decrease around a point source in water for the above-named isotopes, with small deviations, follows the inverse square law and is therefore independent of isotope and photon energy. This results from a nearly complete compensation of absorption by scattering in the vicinity of the source. Depending on the isotope, the correction F(r) for absorption and scattering up to distances of 5 cm ranges between 0% and 8% (Fig. 1) (Dutreix et al. 1982; Young 1983; Meisberger et al. 1968; Meli et al. 1988).


Source Position Magnification Factor Middlesex Hospital Intracavitary Irradiation Isodose Distribution 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bates TD, Berry RJ (1980) High-dose-rate afterloading in the treatment of cancer of the uterus. Br J Radiol [Special Rep] 17Google Scholar
  2. Busch M (1978) Die Messung der Strahlenbelastung von Blase und Rektum bei der gynäkologischen Kontakttherapie. Strahlentherapie 154: 681–685PubMedGoogle Scholar
  3. Coltart RS, Nethersell ABW, Thoma S, Dixon AV (1987) A CT based dosimetry system for intracavitary therapy in carcinoma of the cervix. Radiother Oncol 10: 295–305PubMedCrossRefGoogle Scholar
  4. Crook JM, Esche BA, Isturiz CCJ, Sentenac I, Horiot JC (1987) Dose-volume analysis and the prevention of radiation sequelae in cervical cancer. Radiother Oncol 8: 321–332PubMedCrossRefGoogle Scholar
  5. Dale RG (1980) Dosimetry of the Charing Cross Cathetron. Br J Radiol [Special Rep] 17: 38–42Google Scholar
  6. Dutreix A, Marinello G, Wambersie A (1982) Dosimétrie en curiethérapie. Masson, ParisGoogle Scholar
  7. Glaser FH, Grimm D, Hänsgen G, Rauh G, Schuchardt V (1985) Klinische Erfahrungen bei der AfterloadingKurzeittherapie im Vergleich zur konventionellen Brachytherapie bei der Behandlung gynäkologischer Tumoren. Strahlentherapie 161: 459–475PubMedGoogle Scholar
  8. Himmelmann A, Ragnhult I (1983) High dose-rate after-loading treatment in carcinoma of the uterine cervix using an individual planning and reconstruction system. Acta Radiol [Oncol] (Stockh) 22: 263–271Google Scholar
  9. Himmelmann A, Karlstedt K, Ragnhult I (1980) Early experience with high dose-rate (Ralstron) treatment in Göteborg. Br J Radiol [Special Rep] 17: 106–110Google Scholar
  10. Himmelmann A, Bjurstam N, Ragnhult I (1983) Computed tomography of the cervix and distances to the bladder and rectum in intracavitary radiation treatment of gyneological cancer. Strahlentherapie 159: 198–202PubMedGoogle Scholar
  11. International Commission on Radiation Units and Measurements (ICRU) (1985) Dose and volume specification for reporting intracavitary therapy in gyneology. ICRU, Bethesda (Report no 38 )Google Scholar
  12. Kuipers T, Visser AG (1986) Technical aspects of bladder dosimetry in intracavitary irradiation of cervix carcinoma. Radiother Oncol 7: 7–12PubMedCrossRefGoogle Scholar
  13. Mak ACA, van’t Riet A, Ypma AFGM, Veen RE, van Slooten FHS (1987) Dose determination in bladder and rectum during intracavitary irradiation of cervix carcinoma. Radiother Oncol 10: 97–100PubMedCrossRefGoogle Scholar
  14. Meisberger LL, Keller RJ, Shalek RI (1968) The effective attenuation in water of the gamma rays of gold-198, iridium-192, cesium-137, radium-226 and cobalt-60. Radiology 90: 953–957PubMedGoogle Scholar
  15. Meli JA, Meigooni AS, Nath R (1988) On the choice of phantom material for dosimetry of Ir–192 sources. Int J Radiat Oncol Biol Phys 14–587–594Google Scholar
  16. Planskoy B, Lim A (1980) Cathetron dosimetry at the Middlesex Hospital, London. Br J. Radiol [Special Rep] 17: 45–49Google Scholar
  17. Snelling MD, Lambert HE, Yarnold L (1980) Clinical results and complications following treatment of carcinoma of the cervix and endometrium using Cathetron at Middlesex Hospital. Br J Radiol [Special Rep] 17: 33–37Google Scholar
  18. Thesen N (1985) Bestrahlungstechnik, Dokumentation und individuelle Dosimetrie bei der intrakavitären KurzzeitAfterloadingtherapie. Strahlentherapie 161: 476–486PubMedGoogle Scholar
  19. Ward AJ, Stubbs B, Dixon B, Firth LA (1980) A shedule of radiotherapy, including the use of the Cathetron for advanced carcinoma of the cervix. Br J Radiol [Special Rep] 17: 17–23Google Scholar
  20. Young ME (1983) Radiological physics, 3rd edn. Lewis LondonGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1991

Authors and Affiliations

  • Norfried Thesen
    • 1
  1. 1.Klinik und Poliklinik für StrahlentherapieUniversität zu KölnKöln 41Germany

Personalised recommendations