PHILADELPHIA (October 23, 2022)—It’s common for lung cancer patients receiving radiation therapy to miss a few treatment days. But how many missed days is too many? And can providers make up for the delayed treatments by increasing the radiation dose?
New research from Fox Chase Cancer Center confirms that the more treatments a patient skips, the higher their risk for death. At the same time, the study, which was presented today at the 2022 American Society for Radiation Oncology (ASTRO) Annual Meeting, shows that some of these patients may benefit from receiving higher radiation doses if they do miss treatments.
The study is part of a larger trend toward developing more personalized cancer care, said first author Peter Lee, MD, PhD, a radiation oncology resident in the Department of Radiation Oncology at Fox Chase.
“Ideally, we can begin to adapt treatment to the individual patient,” he said. “So if a patient misses a certain number of days, we can change their prescription and add on a higher dose as they finish their treatment.”
Lung cancer patients receiving radiation therapy typically undergo intensive treatment over a long period of time, often five days a week for up to six weeks. During that time, many patients miss a few treatment days for weather, illness, or other reasons. These days are made up later, prolonging treatment.
“For the most part we reassure patients, saying, ‘It’s not a big deal, you can miss a day, we can add it on at the end, no problem,’” Lee said. “But at the same time, we do know that, ideally, you should get the treatment done as prescribed and not miss any days.”
For the study, researchers looked at data on more than 26,000 patients with stage III non-small cell lung cancer who received chemoradiation therapy and no other treatment. Of this group, 8,644 had their treatment prolonged due to missed days. While all the patients had radiation doses within the standard of care, some received a total dose of 60 gray, while others received a slightly higher total dose of 66 gray.
The study showed that there wasn’t a threshold of missed days that triggered increased mortality, but the risk of death did rise steadily with the number of days a patient skipped.
In addition, researchers found that there seems to be a window where receiving a higher radiation dose may balance out the missed days. Specifically, low-dose patients who missed four to nine treatment days had a significantly higher risk of death than patients who were receiving the higher radiation dose.
“Patients who were delayed by 10 or more days didn’t see this benefit,” Lee said. “That may suggest that once you reach that point, the higher dose isn’t going to make up for missing so many days.”
Lee noted that while the study shows a clear relationship between missed treatments and death, it doesn’t necessarily show a cause. Patients who skip days due to illness or side effects may have been sicker at the start of treatment and more likely to die due to other causes.
The researchers are planning a similar study in lung cancer patients undergoing surgery and chemotherapy in addition to radiation treatment.
The title of the study is “Increasing Radiation Dose in the Setting of Treatment Prolongation for Stage III Non-Small Cell Lung Cancer (NSCLC).”