ABSTRACT
Intensity-modulated radiotherapy (IMRT) has been a significant technological advance in the field of radiotherapy in recent years. IMRT allows sparing of normal tissue while delivering radical radiation doses to the target volumes. The role of IMRT for parotid salivary gland sparing in head and neck cancer is well established. The utility of IMRT for pharyngeal constrictor muscle and cochlear sparing requires investigation in clinical trials. The current evidence supporting the use of IMRT in various head and neck subsites has been summarized. Sparing of organs at risk allows for dose-escalation to the target volumes, taking advantage of the steep dose-response relationship for squamous cell carcinomas to improve treatment outcomes in advanced head and neck cancers. However, dose-escalation could result in increased radiation toxicity (acute and late), which has to be studied in detail. The future of IMRT in head and neck cancers lies in exploring the use of biological imaging for dose-escalation using targeted dose painting.
Subject(s)
Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/pathology , Carcinoma, Squamous Cell/radiotherapy , Clinical Trials as Topic , Cochlea/pathology , Cochlea/radiation effects , Dose-Response Relationship, Radiation , Head and Neck Neoplasms/diagnosis , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/radiotherapy , Humans , Pharyngeal Muscles/pathology , Pharyngeal Muscles/radiation effects , Radiation Injuries/prevention & control , Radiation Monitoring , Radiation Oncology/methods , Radiation Oncology/trends , Radiotherapy Dosage , Radiotherapy, ConformalABSTRACT
Despite significant improvements in the treatment and outcomes of patients with squamous cell carcinoma of the head and neck (SCCHN) that have resulted from technological advances in radiation delivery and the use of cytotoxic chemotherapy, there is still a pressing need for novel therapies. In the last two decades, our understanding of the molecular biological basis of cancer has provided us with a new framework for developing specific targeted therapies. It is likely that the next wave of developments will include active small molecule inhibitors of epidermal growth factor receptor (EGFR) (and other members of the c-erbB family of receptors), antiangiogenic agents, and drugs that can increase proapoptotic signaling in cancer cells. As with cetuximab, it is most likely that these new agents will first find a niche in the context of combination regimens with standard anticancer therapeutics.