Zeitfaktor und Zeit-Dosis-Verschreibung in der Strahlentherapie von Kopf-Hals-Tumoren

BACKGROUND: Clinical data on head and neck tumors presented by Withers et al. are reexamined. Recently it was argued that the relationship between TCD50 and treatment time might be influenced by the practice of prescription.

METHOD: In a computer simulation the impact of treatment outcome on the time factor is investigated. For this the genuine local tumor control rates were replaced by either tumor failure rate or by random numbers.

RESULTS: The time factor is independent from local tumor control rates in all simulations.

CONCLUSIONS: The increase of TCD50 with treatment time reflects solely dose-time prescription habits. The data provide no significant evidence either for an impact of treatment duration or for repopulation during radiotherapy in head and neck tumors.