Clinical heterogeneity and tumor control probability.
Heterogeneity in tumor sensitivity to therapy within patient populations is a major factor affecting tumor control probability (TCP) models, typically flattening dose-response curves. Knowledge of the major clinical factors affecting TCP would allow incorporation of these factors into TCP models, or stratification of patients and tumors, yielding steeper and more specific and predictive TCP curves.


METHODS
Literature review of the results of therapy for oropharyngeal cancer.


RESULTS
In recent years an improvement in control rates of cancers such as oropharyngeal cancer has been reported as potentially gained due to the dosimetric superiority of intensity modulated radiotherapy (IMRT). However, the emergence of Human Papilloma Virus (HPV)-related oropharyngeal cancer in recent years is an example of a major clinical factor which likely supersedes the dosimetric gains of IMRT.


CONCLUSIONS
Clinical factors such as the example discussed in this paper: HPV-related oropharyngeal cancer, must be taken into account in TCP models in order for such models to be relevant.
Eisbruch
Avraham
A
Department of Radiation Oncology, University of Michigan, Ann Arbor, USA. eisbruch@umich.edu
D052685:Alphapapillomavirus; D004307:Dose-Response Relationship, Radiation; D006801:Humans; D009959:Oropharyngeal Neoplasms / Q000532:radiotherapy* / Q000821:virology*; D030361:Papillomavirus Infections / Q000150:complications*; D011336:Probability; D011836:Radiation Tolerance; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D050397:Radiotherapy, Intensity-Modulated; D014412:Tumor Virus Infections / Q000150:complications / Q000821:virology