SALT LAKE CITY—Although radiation- induced toxicities are common in an outpatient setting, several treatment options have proven very successful—as long as the appropriate monitoring parameters are in place, according to a presentation at the annual meeting of the Hematology/Oncology Pharmacy Association by Makala Pace, PharmD, BCOP, clinical pharmacy specialist at The University of Texas M. D. Anderson Cancer Center in Houston.
She noted that the most widely used radiation therapy is currently external beam radiation, which includes 3- dimensional conformal and intensitymodulated radiation therapies, stereotactic radiation therapy/surgery, and proton therapy. Internal radiation (including brachytherapy) and systemic radiation therapy (including radiopharmaceuticals) are also common.
The development of radiation-related toxicity is dependent on several factors, including the area of body treated, the total dose given, the patient’s performance status, and concurrent therapy. The levels of toxicity are categorized into acute (occurring during treatment), subacute (developing between 2 weeks and 3 months after therapy), and chronic (occurring more than 6 months after treatment).
According to Pace, the most common adverse effects include radiation dermatitis, mucositis and dysgeusia, esophagitis, parotitis, otitis, genitourinary conditions such as acute cystitis or obstructive urinary symptoms, diarrhea, and proctitis.
For grade 1 radiation dermatitis, the National Cancer Institute recommended application 3 times daily of nonionic moisturizers, such as Cetaphil, Aveeno, or Lubriderm; of hydrocortisone 1% cream; or of Biafine topical emulsion. For grade 2 and 3, they recommend normal saline or modified Burow’s solution compresses, Polymyxin B/Neomycin cream, or a hydrogel.
For grade 4, other treatment options include treating the infection, debridement of the tissue, application of vitamin E and pentoxifylline, and flexible hydroactive hydrocolloid dressings. The latter helps the wound to “autolytically debride itself ” and is “best applied to wounds that produce light to medium exudate or transudate,” explained Pace. She cautioned that these dressings should not be applied over infected wounds and can give off a foul odor 2 to 4 days after application.
Regardless of grade, all patients with radiation dermatitis should keep sun exposure from the affected area, should be made aware that different affected areas may require different treatment approaches, and should not apply lotions or gels immediately before undergoing radiotherapy.
Recommended treatments for mucositis include an electrolyte solution, such as the supersaturated calcium phosphate rinse Caphosol that resembles human saliva, lidocaine/diphenhydramine/ simethicone, antifungals, or a protective barrier such as sucralfate or Gelclair bioadherent oral gel. For dysgeusia, the recommendations include zinc sulfate, a weekly infusion of amifostine 500 mg, or time—as regeneration may take up to 4 months.
Other radiation-induced side effects and recommended treatments include:
- Dental caries/tooth decay: tooth extraction or fluoride gels
- Esophagitis: lidocaine, nutritional support, protective barriers, or acid suppressants
- Inflammation of a parotid gland: aspirin or nonsteroidal anti-inflammatory drugs
- Dry mouth: pilocarpine, artificial saliva, amifostine, or cevimeline
- Otis externa: hydrocortisone/ neomycin/polymyxin B ear drops (with decongestants or phenylephrine otic solution for serious otitis)
- Acute cystitis: phenazopyridine or oxybutynin
- Obstructive urinary symptoms: oxybutynin, tamsulosin, finasteride, or terazosin
- Diarrhea: low-residue diet, loperamide, cholestyramine, or octreotide.