Organ-sparing radiation therapy for head and neck cancer

Abstract

To improve locoregional tumor control and survival in patients with locally advanced head and neck cancer (HNC), therapy is intensified using altered fractionation radiation therapy or concomitant chemotherapy. However, intensification of therapy has been associated with increased acute and late toxic effects. The application of advanced radiation techniques, such as 3D conformal radiation therapy and intensity-modulated radiation therapy, is expected to improve the therapeutic index of radiation therapy for HNC by limiting the dose to critical organs and possibly increasing locoregional tumor control. To date, Review articles have covered the prevention and treatment of radiation-induced xerostomia and dysphagia, but few articles have discussed the prevention of hearing loss, brain necrosis, cranial nerve palsy and osteoradionecrosis of the mandible, which are all potential complications of radiation therapy for HNC. This Review describes the efforts to prevent therapy-related complications by presenting the state of the art evidence regarding advanced radiation therapy technology as an organ-sparing approach.

Dysphagia and trismus after concomitant chemo-Intensity-Modulated Radiation Therapy (chemo-IMRT) in advanced head and neck cancer; dose–effect relationships for swallowing and mastication structures

“…Also, other recently published reviews e.g. , Cartmill (2012), Nutting (2012), Bhide (2012) and colleagues, concluded that although the evidence is small, a number of dosimetric constraints might be influential in minimizing the negative impact on swallowing, and potentially on nutritional outcomes [4,5,16,18] .…”

“…Several studies have shown that IMRT in head and neck cancer treatment reduces overall adverse effects such as xerostomia and dysphagia, and thus improves quality of life, even when chemotherapy is added to IMRT (chemo-IMRT) [1][2][3][4][5]. It appears possible to limit the dose to the musculature involved in swallowing and mastication without compromising radiation to the tumor site(s) [2,3,5,6]. In many institutes, therefore, IMRT has become the standard of care in head and neck cancer.…”

Weekly kilovoltage cone-beam computed tomography for detection of dose discrepancies during (chemo)radiotherapy for head and neck cancer

“…For the clinical target volume (CTV) a margin of 5 -10 mm was added to GTV and corrected for anatomical boundaries. The elective nodal volumes were defi ned per national guidelines [1]. A uniform margin of 4 mm was added to CTV to correct for systematic and random patient setup uncertainties resulting in the planning target volume (PTV).…”

Optimising intratumoural treatment of head and neck squamous cell carcinoma mouse models with EBC-46

“…Patient's commonly suffer from xerostomia, dysphagia, and hearing loss, whilst osteoradionecrosis of the mandible, radiation-induced nerve palsy, and cerebral radiation necrosis are much less common [40]. Salvage surgery for recurrent disease is also made difficult in a previously irradiated region, secondary to significant fibrosis and loss of normal tissue planes.…”

“…Post-operative radiotherapy is often commenced six weeks postoperatively, allowing for adequate tissue healing, and delivers 60-66 Gy [30]. The advent of intensity-modulated radiation therapy, allows radiation oncologists to deliver radiation in 3 dimensions using CT-planning thus targeting specific sites and avoiding structures at risk such as the optic nerves, brain stem, spinal cord, salivary glands, inner ear, swallowing structures and mandible [40].…”