Very small differences in the way a patient lies during radiotherapy treatment for lung or esophageal cancer can have an impact on how likely they are to survive, according to research presented at the ESTRO 37 conference held April 20-24 in Barcelona.
These differences of only a few millimetres can mean that the radiation treatment designed to target patients’ tumors can move fractionally closer to the heart, where it can cause unintentional damage and reduce survival chances.
The finding suggests that survival could be improved by tightening up treatment guidelines to ensure patients are positioned more accurately.
Radiotherapy plays an important role in cancer care in, amongst others, hard to treat tumors such as lung and esophageal cancer. However, it can cause side effects and previous research shows that radiotherapy to the chest can have negative long-term effects on the heart, for example, increasing the risk of heart disease.
When planning radiotherapy treatment, cancer specialists create a CT image of their patient. This reveals the exact position and size of the tumor within the body. At each subsequent treatment, another image is created and used to check that the patient and, therefore, the tumor is in the same position, within a certain threshold, before the treatment is delivered.
The new research was presented by Corinne Johnson, a medical physics PhD student at the Manchester Cancer Research Centre, part of the Christie NHS Foundation Trust and the University of Manchester, UK.