Radiation therapy plays a central role in the treatment of head and neck (H&N) cancer patients worldwide. Conventional H&N radiation is routinely associated with acute and long-term toxicities which derive from the spectrum of normal tissues encompassed within the radiation design. Although intensified radiation fractionation and concurrent radiochemotherapy programs provide increasing promise for enhanced tumor control rates, these methods are generally accompanied by an increase in normal tissue toxicity. Efforts to diminish the routine toxicities associated with H&N radiotherapy offer potential to improve patient quality of life without compromise in tumor control. The overall objective of this project is to examine the capacity of tomotherapy to conformally avoid selected normal structures in the treatment of H&N cancer patients. We hypothesize that conformal avoidance tomotherapy will allow comprehensive H&N radiation coverage of the primary tumor and regional lymphatics with significant sparing of dose to specified normal tissue structures. Whereas critical normal tissues can be precisely delineated on imaging studies, the tissues t risk for potential tumor invasion or occult regional nodal spread are considerably less certain. Step 1 in this project will involve precise characterization and quantitative analysis of normal tissues damage to parotid glands and auditory apparatus in H&N cancer patients undergoing conventional shrinking-field H&N radiotherapy. Experimental generation of tomotherapy treatment plans in patients undergoing conventional H&N radiotherapy will be performed so as to gain expertise in common patterns of tomotherapy field design for complex H&N cancer patients. Step 2 will involve the treatment of a pilot cohort of H&N cancer patients with helical tomotherapy, incorporating analysis of daily treatment setup using the infrared radiocamera using to precisely monitor and adjust for variations in day-to-day patient positioning. Step 3 will involve delivery of conformal avoidance tomotherapy to H&N cancer patients within the context of a Phase II clinical trial. Setup verification analysis will be extended in Step 3 and the process of treatment delivery modification will be examined. Physiological testing (salivary and auditory) as well as patient-driven quality of life analysis will be performed for all patients. The precision characteristics of conformal avoidance tomotherapy are uniquely suited to accomplish selective normal tissue sparing in H&N cancer patients. This effort is anticipated to enhance overall health status and quality of life in H&N cancer patients.
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