Head/Neck Radiation Patients
Head and neck radiation patients are a significant challenge relative to both intratherapy and posttherapy oral complications resulting from radiation therapy. Unlike the oral complications of chemotherapy that are of shorter duration and significant for only a short period (a few weeks to 2 months) after the cessation of therapy, the oral complications of head and neck radiation are more predictable, are often more severe, and can lead to permanent tissue changes that put the patient at risk for serious chronic complications.
Preradiation Dental Evaluation and Oral Disease Stabilization
Elimination of oral disease and implementation of oral care protocols designed to maintain maximum oral health must be components of patient assessment and care before radiation therapy begins. During and after radiation therapy, oral management will be dictated by the following:
- Specific needs of the patient.
- Specifics of the radiation therapy.
- Chronic complications caused by radiation therapy.
Ongoing oral assessment and treatment of complications are essential because radiation to oral tissues typically conveys a lifelong risk of oral complications. In addition, invasive oral procedures can cause additional sequelae. Dental care typically needs to be altered because of underlying chronic radiation-induced tissue damage.
Patients should receive a comprehensive oral evaluation several weeks before high-dose upper-mantle radiation begins. This timing provides an appropriate interval for tissue healing in the event that invasive oral procedures, including dental extractions, dental scaling/polishing, and endodontic therapy, are necessary. The goal of this evaluation is to identify teeth at significant risk of infection and/or breakdown that would ultimately require aggressive or invasive dental treatment during or after the radiation that increases the risk of soft tissue necroses and osteonecroses. The likelihood of these lesions occurring postradiation increases over the patient’s lifetime as the risk of significant dental disease (restorative, periodontal, and endodontic) increases. Salivary gland hypofunction and xerostomia frequently occur postradiation. It is thus especially important that preradiation dental care strategies are instituted to reduce the impact of the complications of severely decreased saliva secretion and the associated high risk of dental caries.
In addition, three radiation-specific issues emerge:
- Radiation injury is oral tissue–specific and dependent on dosage and portals of therapy.
- Radiation-induced oral mucositis typically lasts 6 to 8 weeks, versus the approximate 5 to 14 days observed in chemotherapy patients. The extended radiation treatment protocols are chiefly responsible for this difference.
- The primary cause of oral cancer is tobacco use; alcohol abuse further escalates risk. It is therefore critical that head/neck cancer patients permanently cease tobacco use. (Refer to the PDQ summary on Smoking in Cancer Care for more information.)
- Most patients with smoking-related cancer appear motivated to quit smoking at the time of cancer diagnosis.
- Continued smoking substantially increases the likelihood of recurrence or occurrence of a second cancer in survivors, particularly in those who previously received radiation therapy.
- A stepped-care approach to tobacco cessation is recommended, including direct physician advice to quit and provision of basic information to all patients at each contact during the first month of diagnosis, followed by more intensive pharmacologic treatment or counseling for those having difficulty quitting or remaining abstinent.
Oral Complications of Head and Neck Radiation
The oral complications of head and neck radiation can be divided into two groups on the basis of the usual time of their occurrence:
- Acute complications occurring during therapy.
- Late complications occurring after radiation therapy has ended.
Acute complications include the following:
- Oropharyngeal mucositis.
- Sialadenitis and xerostomia.
- Infections (primarily candidiasis).
- Taste dysfunction.
Occasionally, tissue necrosis can be seen late during therapy, but this is relatively rare.
Chronic complications include the following:
- Mucosal fibrosis and atrophy.
- Decreased saliva secretion and xerostomia.
- Accelerated dental caries related to compromised saliva secretion.
- Infections (primarily candidiasis).
- Tissue necrosis (soft tissue necrosis and osteonecrosis).
- Taste dysfunction (dysgeusia/ageusia).
- Muscular and cutaneous fibrosis.
Management of oral mucositis
The etiopathogenesis of mucositis caused by head and neck radiation appears to be similar but not identical to mucositis caused by high-dose chemotherapy.[3-5] Management strategies described for chemotherapy/hematopoietic stem cell transplantation are generally applicable to the head/neck radiation patient.[6,7] (Refer to the Management of mucositis section of this summary for more information.) In one study, gabapentin appeared promising in reducing the need for narcotic pain medication for patients with head and neck malignancies treated with radiation therapy.[Level of evidence: III]
The extensive duration and severity of radiation mucositis combined with the treatment of most radiation patients as outpatients results in pain management challenges. As mucositis severity increases and topical pain management strategies become less effective, it becomes increasingly necessary to depend on systemic analgesics to manage oral radiation mucositis pain:
- Because there is generally no risk of bleeding for head and neck radiation patients, analgesic treatment begins with nonsteroidal anti-inflammatory drugs (NSAIDs).
- As pain increases, NSAIDs are combined with opioids, and patients can be made relatively comfortable.
Doses for NSAIDs are titrated up to their recommended dosing ceiling; on the other hand, opioids are titrated to effective pain relief. Systemic analgesics are given by the clock to achieve steady-state blood levels to provide adequate pain relief.
Additionally, adjunctive medications are given to provide adjuvant analgesia and manage side effects of NSAIDs and opioids. Zinc supplementation used with radiation therapy may improve mucositis and dermatitis.[Level of evidence: I] The use of alcohol-free povidone-iodine mouthwash may reduce the severity and delay the onset of oral mucositis caused by antineoplastic radiation therapy.[Level of evidence: I]
A systematic review indicated that the weighted mean prevalence of clinical oral candidiasis during head and neck radiation therapy is 37.4% and may be significantly higher in patients who receive concurrent chemotherapy. Factors promoting clinical fungal infection in this population include the following:
- Hyposalivation resulting from radiation damage to the salivary glands.
- Tissue damage caused by radiation-induced oral mucositis.
- Resulting dietary impairment.
- Inability to maintain oral hygiene.
Because these patients are usually not significantly neutropenic, topical antifungal agents such as nystatin rinse/pastilles and clotrimazole troches can be effective. The use of a troche may be limited by significant xerostomia. Patients who receive topical antifungals should be asked to avoid eating, drinking, or rinsing for at least 30 minutes after use. Patients with removable dentures should remove the dentures before using the topical antifungals and should also treat the dentures to avoid repeat colonization of the oral tissues by fungal organisms that are colonizing the dentures.
For persistent lesions, systemic agents such as fluconazole are very effective.
As oral and pharyngeal mucosa are exposed to radiation, taste receptors become damaged, and taste discrimination becomes increasingly compromised.[13,14] After several weeks of radiation therapy, patients commonly complain that they have no sense of taste. It will generally take 6 to 8 weeks after the end of radiation therapy for taste receptors to recover and become functional. Zinc sulfate supplements (220 mg 2 or 3 times a day) have been reported to help with recovery of the sense of taste.[15,16][Level of evidence: I]
- Vera-Llonch M, Oster G, Hagiwara M, et al.: Oral mucositis in patients undergoing radiation treatment for head and neck carcinoma. Cancer 106 (2): 329-36, 2006. [PUBMED Abstract]
- Caudell JJ, Schaner PE, Meredith RF, et al.: Factors associated with long-term dysphagia after definitive radiotherapy for locally advanced head-and-neck cancer. Int J Radiat Oncol Biol Phys 73 (2): 410-5, 2009. [PUBMED Abstract]
- Sonis ST: Mucositis as a biological process: a new hypothesis for the development of chemotherapy-induced stomatotoxicity. Oral Oncol 34 (1): 39-43, 1998. [PUBMED Abstract]
- Sonis ST, Peterson DE, McGuire DB, eds.: Mucosal injury in cancer patients: new strategies for research and treatment. J Natl Cancer Inst Monogr (29): 1-54, 2001.
- Barasch A, Peterson DE: Risk factors for ulcerative oral mucositis in cancer patients: unanswered questions. Oral Oncol 39 (2): 91-100, 2003. [PUBMED Abstract]
- Demarosi F, Bez C, Carrassi A: Prevention and treatment of chemo- and radiotherapy-induced oral mucositis. Minerva Stomatol 51 (5): 173-86, 2002. [PUBMED Abstract]
- Shih A, Miaskowski C, Dodd MJ, et al.: A research review of the current treatments for radiation-induced oral mucositis in patients with head and neck cancer. Oncol Nurs Forum 29 (7): 1063-80, 2002. [PUBMED Abstract]
- Bar Ad V, Weinstein G, Dutta PR, et al.: Gabapentin for the treatment of pain related to radiation-induced mucositis in patients with head and neck tumors treated with intensity-modulated radiation therapy. Head Neck 32 (2): 173-7, 2010. [PUBMED Abstract]
- Wong PC, Dodd MJ, Miaskowski C, et al.: Mucositis pain induced by radiation therapy: prevalence, severity, and use of self-care behaviors. J Pain Symptom Manage 32 (1): 27-37, 2006. [PUBMED Abstract]
- Lin LC, Que J, Lin LK, et al.: Zinc supplementation to improve mucositis and dermatitis in patients after radiotherapy for head-and-neck cancers: a double-blind, randomized study. Int J Radiat Oncol Biol Phys 65 (3): 745-50, 2006. [PUBMED Abstract]
- Madan PD, Sequeira PS, Shenoy K, et al.: The effect of three mouthwashes on radiation-induced oral mucositis in patients with head and neck malignancies: a randomized control trial. J Cancer Res Ther 4 (1): 3-8, 2008 Jan-Mar. [PUBMED Abstract]
- Lalla RV, Latortue MC, Hong CH, et al.: A systematic review of oral fungal infections in patients receiving cancer therapy. Support Care Cancer 18 (8): 985-92, 2010. [PUBMED Abstract]
- Nelson GM: Biology of taste buds and the clinical problem of taste loss. Anat Rec 253 (3): 70-8, 1998. [PUBMED Abstract]
- Zheng WK, Inokuchi A, Yamamoto T, et al.: Taste dysfunction in irradiated patients with head and neck cancer. Fukuoka Igaku Zasshi 93 (4): 64-76, 2002. [PUBMED Abstract]
- Silverman S Jr: Complications of treatment. In: Silverman S Jr, ed.: Oral Cancer. 5th ed. Hamilton, Canada: BC Decker Inc, 2003, pp 113-28.
- Ripamonti C, Zecca E, Brunelli C, et al.: A randomized, controlled clinical trial to evaluate the effects of zinc sulfate on cancer patients with taste alterations caused by head and neck irradiation. Cancer 82 (10): 1938-45, 1998. [PUBMED Abstract]