Get an Overview of Radiation Therapy for Cancer

February 27, 2018 by Kathleen Wiley MSN, RN, AOCNS®

Radiation therapy is a precise cancer treatment that targets tumor cells specifically and spares healthy surrounding tissues. Contrary to pharmacologic treatment methodologies, side effects are predominantly site-specific. 

One of the most problematic side effects challenging oncology nurses are skin reactions. Dependent on dose intensity and time over which treatment is delivered, skin reactions can range from mild erythema to debilitating desquamation and ulceration, greatly impeding quality of life. The overall goal in skin reaction management is to keep the skin intact, support epithelial recovery, and ultimately prevent superinfection. Unfortunately, so many compounding variables and approaches to topical care have greatly limited the availability of well-designed randomized trials to guide clinicians in the topical management of skin reactions. However, best-available evidence (https://www.ons.org/store/books/manual-radiation-oncology-nursing-practice-and-education-fourth-edition) points to application of hydrophilic agents and cleansing with water and mild soap.

Fatigue, a non–site-specific side effect of radiation, aggressively impacts patients. Research points to being able to correlate (https://doi.org/10.1188/15.CJON.744-750) lower baseline hematology markers (e.g., red blood cell count, hemoglobin, hematocrit) as predictive indicators of the likelihood and severity of fatigue experienced among patients undergoing radiotherapy for certain disease types, including breast and prostate cancer. Moderate exercise and maintaining a therapeutic hemoglobin level seem to be effective in combating radiation-induced fatigue. 

Nurses must also recognize that although radiation continues to be used in combination regimens with chemotherapy, a growing body of evidence is emerging showing benefit in combining radiotherapy with immunotherapy agents. Evidence suggests that cell death by radiation helps to present tumor associated antigens and that radiation itself can enhance immune activity. All nurses caring for patients undergoing treatment for cancer must be familiar with the concepts for radiotherapy and patient management, regardless of practice specialty and location.

Radiation and Genomics

In 2017, we saw a surge in the information that genomics affords cancer care providers. Identification of specific tumor markers contributes to treatment decision making as more agents emerged that target specific tumor markers. But genomics is proving successful in radiotherapy as well. Researchers discovered that patient-specific genomic data impacts patients’ response to radiation therapy and the severity of the toxicities they are likely to experience. For example, when a single DNA nucleotide, known as a single nucleotide polymorphism, is altered, it can promote radiation induced fibrosis or inflammation. Furthermore, when XRCC1 and XRCC3 genes are mutated, correlations are noted (https://doi.org/10.1188/14.CJON.185-189) between acute mucositis and dermatitis and severe dysphagia, respectively. Understanding genetic mutations aids nurses in individualizing their approach to assessment, toxicity management, and patient education. Much remains to be learned regarding genomics and radiation therapy relationships, but knowing presence of certain mutations that are associated with more intense toxicities, may also lead to fractionation modifications.

Survivorship

More than half of all patients with cancer (https://doi.org/10.1188/14.CJON.185-189) will receive radiation treatment over the course of the cancer trajectory. As survival rates improve, healthcare professionals must be astutely aware of the survivorship issues facing patients with cancer who received radiotherapy. Late and chronic effects are related to the site, dose, and intensity of treatment and may include osteoporosis, arthralgias, immune suppression, and hormone deficiencies. Patients are also at risk for long-term pulmonary and cardiac conditions depending on the field of radiation, and those affected require careful consideration and assessment throughout their lifetime (https://www.ons.org/store/books/manual-radiation-oncology-nursing-practice-and-education-fourth-edition).

Secondary malignancies must also be considered because patients who received targeted radiotherapy are at an increased risk for secondary cancer diagnoses. Despite advances in targeting tumors and minimizing damage to healthy tissue, any organ exposed to the radiation field is at risk for secondary malignancy.  For example, a patient previously treated for lymphoma involving the lung fields may be at risk for a secondary lung cancer. Additionally, patients, especially children, who underwent total body irradiation prior to hematopoietic stem cell transplantation are at an increased risk for brain and thyroid tumors (https://www.ons.org/store/books/manual-radiation-oncology-nursing-practice-and-education-fourth-edition).

Patients undergoing radiotherapy require a great deal of education and counseling prior to and throughout treatment. Important concepts to cover include intent of therapy, planned supportive care and adherence to skin care regimens, protecting caregivers from radiation exposure if applicable, and potential side effects and their preventive and management strategies. Advancements in research and approaches to radiotherapy are helping oncology nurses to better predict response to treatment and plan for supportive care.  


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