Dysgeusia Head and Neck

patients may develop anorexia due to dysgeusia and therefore nutritional status must be moni- tored closely. Zinc and amifostine for prophy- laxis or treatment of dysgeusia in adult patients have not consistently shown benefi t and are not recommended Hovan et al. 2010 . Dysgeusia usually returns to normal weeks to months after the completion of RT though in a small subseg- ment of patients may persist.

13.5.3 Xerostomia

A reduction in salivary function is most com- monly seen with head and neck RT and has also been noted post-HSCT with and without TBI Jensen et al. 2010a . In a systematic review by Jensen et al. 2010a , xerostomia prevalence remained 70 from the time of development to 2 years post conventional RT. Pediatric data are limited; it appears the risk of chronic xerostomia is low although has been described after both head and neck RT and TBI conditioning with HSCT Jensen et al. 2010a . Xerostomia risk is dose related, with minimal risk at mean doses of 10–15 Gy to the parotid gland and a decrease in glandular function 75 with mean doses 40 Gy Deasy et al. 2010 . Xerostomia risk has been reported to be signifi cantly reduced with sparing of one parotid or even, potentially, one submandibular gland, with IMRT although in the review by Jensen et al. 2010a prevalence of xero- stomia after IMRT was similar to that noted with conventional RT at all time points due to variation in technique and ability to spare the parotid and submandibular glands Saarilahti et al. 2006 . Multiple potential management strategies exist in the adult literature and have most recently been systematically reviewed by Jensen et al. 2010b as part of MASCCISOO. Recommendations include the use of IMRT with salivary gland spar- ing when oncologically feasible, muscarinic ago- nist stimulation pilocarpine over newer and less well-studied agents cevimeline and bethanechol after RT completion but not during RT, oral mucosal lubricantssalivary substitutes, salivary gland transfer in strictly selected cases, and acu- puncture to stimulate salivary gland secretion Jensen et al. 2010b . Agents that are not recom- mended include amifostine as opposed to the 2008 ASCO guidelines by Hensley et al. [ 2009 ], gustatory and masticatory stimulation sugar-free lozenges, acidic candy, chewing gum, and hyper- baric oxygen HBO therapy Jensen et al. 2010b . Pediatric data on such interventions are extremely limited.

13.5.4 Ear Complications

Depending on the extent of the radiation fi eld and cumulative dose, patients have been reported to acutely develop serous otitis media and externa in addition to radiation dermatitis of the external ear and ear canal. Otitis media occurs in conjunc- tion with mucosal edema leading to tinnitus and high-frequency hearing loss in rare cases requir- ing myringotomy tubes Chopra and Bogart 2009 . Excessive earwax buildup has also been noted after the completion of RT Chopra and Bogart 2009 . Patients may require deconges- tants and oral antibiotics for serous otitis media, otic antibiotic drops for otitis externa, and carb- amide peroxide ear drops for wax buildup. Corticosteroid drops can be utilized for radiation dermatitis in the external ear canal. Audiometric testing should be done on clinically symptomatic patients. Sensorineural deafness, a late effect of RT, is dose dependent and permanent, occurring at 50 Gy and synergistic with platinum chemo- therapy Huang et al. 2002 . Tissue protection with IMRT has signifi cantly reduced the risk of this complication Huang et al. 2002 .

13.5.5 Laryngeal Complications

Radiation to the oropharynx can lead to laryn- geal edema as well as reduced laryngeal closure resulting in aspiration, especially at doses 50 Gy although risk has been decreased with the use of IMRT Chopra and Bogart 2009 ; Rancati et al. 2010 . Patients should be moni- tored closely and treated symptomatically with antitussives, pain medication, and steroids to reduce edema. RT treatment interruption may be necessary depending on the underlying cause of the edema and the severity. ENT evaluation and hospitalization may be required for more com- plicated cases. Adolescent patients should be advised against smoking during and after RT as it has been reported to lead to persistent hoarse- ness in adults with glottic tumors Chopra and Bogart 2009 .

13.6 Gastrointestinal

Complications The stomach and small bowel are often inciden- tally irradiated when treating upper GI tract, infe- rior lung, retroperitoneal, and pelvic tumors. Acute gastrointestinal RT-induced side effects include nausea, vomiting, and anorexia immedi- ately after treatment as well as dysphagia, esopha- gitis, dyspepsia, ulceration, bleeding, enteritis GI mucositis manifesting as cramping, diarrhea, and malabsorption, and proctitis within the fi rst few weeks of therapy Kavanagh et al. 2010 ; Michalski et al. 2010 . Late small bowel obstruction due to RT-induced fi brosis and secondary adhesions as well as chronic dyspepsia, ulceration, diarrhea, fi stula, perforation, bleeding, strictures, and chronic radiation proctitis must be considered but are beyond the scope of this chapter. RT dose- volume constraints for the stomach and small bowel are diffi cult to determine as partial volume irradiation is usually undertaken; ≥45 Gy for the whole stomach and for partial small bowel 195 mL are thresholds that have been published for adult patients Kavanagh et al. 2010 .

13.6.1 Dysphagia and Esophagitis

Radiation to the oropharynx can lead to pharyn- geal edema as well as dysphagia while RT to the thorax can lead to esophagitis. Adult patients receiving chemoradiation or hyperfractionated RT have been noted to have a 15–25 risk of severe acute esophagitis with symptoms peaking 4–8 weeks after the commencement of RT Werner-Wasik et al. 2010 . Of note, esophageal infections such as oroesophageal OE candidiasis or herpes simplex esophagitis can lead to similar symptoms and must be ruled out; additionally, preexisting gastroesophageal refl ux GER can worsen esophagitis and should be treated Werner- Wasik et al. 2010 . If infection is a concern, patients should undergo diagnostic endoscopy unless the level of symptoms contradicts such a procedure; in such cases empiric therapy e.g., fl u- conazole for OE candidiasis may be required. Radiation doses 40–50 Gy in adults have been shown to correlate with increased risk of acute esophagitis Werner-Wasik et al. 2010 . Data in the pediatric population are lacking. Amifostine has shown some potential benefi t in non-small cell lung cancer patients, but the reports are inconsistent, and recommendation for its use is also not uniform Keefe et al. 2007 ; Hensley et al. 2009 ; Peterson et al. 2011 . No other agent has been well studied; oral sucralfate has been utilized, but data are confl icting, and it is not recommended in consensus guidelines for RT-induced esophagitis Bradley and Movsas 2004 . General treatment strategies include treat- ment of underlying GER with an H 2 blocker or proton pump inhibitor, ruling out and treating infectious etiologies for esophagitis, and prescrib- ing viscous lidocaine and analgesics for pain. Promotility agents such as metoclopramide can also be tried. Patients should be advised to avoid acidic and spicy foods as well as alcohol and cof- fee. Nutritional status should be closely moni- tored, and patients at risk for malnutrition should receive oral supplementation, nasogastric feeds, PEG placement if with a head and neck tumor, or TPN, depending on the underlying clinical sit- uation; see Chap. 12 for more details. Pediatric patients with a history of chemoradiation- induced esophagitis are at risk for esophageal stricture and should be monitored for this potential late compli- cation Mahboubi and Silber 1997 .

13.6.2 Nausea, Vomiting and Anorexia

Radiation-induced nausea and vomiting RINV has been reported to occur in 50–80 of adult patients dependent on the radiation fi eld, RT dose,