Increased Radiation Dose Associated with Increased Fatigue and Dyspnea

Increased Radiation Dose Associated with Increased Fatigue and Dyspnea

February 25, 2020

In this study, increased radiation dose was correlated with an increase in fatigue and dyspnea, as well as a decrease in physical activity, particularly in lung cancer or lymphoma.

According to a study presented at the American College of Cardiology’s Advancing the Cardiovascular Care of the Oncology Patient course, increased radiation dose to the heart was correlated with increased fatigue and dyspnea, as well as decreased physical activity, particularly in lung cancer or lymphoma.1

The researchers suggested that, given their findings, strategies to decrease cardiac radiation therapy dose could lead to improved physical functioning and less fatigue.

“This study suggests that when a patient is treated with thoracic radiation therapy, it can have a negative impact on their quality of life early on. However, engaging in higher levels of physical activity before treatment may help to improve some of these symptoms over time,” lead study author Sheela Krishnan, MD, fellow in the cardiovascular division of the Hospital of the University of Pennsylvania, said in a press release.2 “This study also confirms that increasing levels of physical activity during treatment are associated with concurrent improvements in quality of life. Though we cannot establish a clear causal relationship from these findings, it does emphasize that physical activity and quality of life are closely linked.” 

In this cohort of 130 patients with either breast cancer, lung cancer, or mediastinal lymphoma who were treated with radiation to the chest, researchers collected data before radiation therapy was administered, immediately after the patient had received therapy, and then 5 to 9 months after the completion of radiation therapy. At each timepoint, self-reported physical activity was assessed using the Godin-Shephard Leisure-Time Physical Activity Questionnaire (GSLTPAQ) and quality of life metrics of fatigue and dyspnea were assessed using the Functional Assessment of Chronic Illness Therapy (FACIT) Fatigue and Dyspnea Scales. 

The patients with lung cancer or lymphoma (n = 52) reported an increase in fatigue and dyspnea immediately after radiation therapy, however this later improved. Each 1 Gy increase in mean heart dose of radiation was associated with decreased GSLTPAQ (-0.68 (95% CI, -1.28 to -0.7, = 0.029). Moreover, every 10% increase in the volume of heart receiving a radiation dose of 5 Gy was correlated with a significant reduction in GSLTPAQ scores.

Participants with breast cancer reported significant increases in physical activity and a decrease in fatigue over time. Within this subgroup, there was a non-significant trend observed toward increased fatigue with increasing radiation dose. However, when researchers accounted for differences in radiation and chemotherapy treatment in these patients, high baseline moderate to vigorous GSLPTAQ scores were associated with improvements in fatigue over time.

The researchers suggested that the differences observed between breast cancer and lung cancer and lymphoma participants could be caused by differences in the radiation doses. However, across the entire cohort, accounting for the differences in chemotherapy and radiation dose the patients received, increases in physical activity over time were significantly associated with concurrent improvements in fatigue and shortness of breath.

“While our study is a small study, it suggests that high levels of physical activity prior to initiation of radiation therapy for cancer are associated with better physical functioning and quality of life with cancer treatment,” Krishnan said. “Additional work is still needed to understand the types and timing of exercises that can bring about the greatest benefit.” 

References:

1. Krishnan S, Narayan H, Freedman G, et al. Early Changes in Physical Activity and Quality of Life with Thoracic Radiation Therapy for Breast Cancer, Lung Cancer, and Lymphoma. American College of Cardiology’s Advancing the Cardiovascular Care of the Oncology Patient course, control #60. acc.org//~/media/Non-Clinical/Files-PDFs-Excel-MS-Word-etc/Meetings/2020/CO-Posters/60%20-%20Krishnan.pdf. acc.org//~/media/Non-Clinical/Files-PDFs-Excel-MS-Word-etc/Meetings/2020/CO-Abstracts/60%20-%20Krishnan.pdf.

2. Radiation Therapy to Heart Can Worsen Fatigue, Shortness of Breath in Cancer Patients [news release]. Washington. Published February 14, 2020. Accessed February 14, 2020.