Researchers at The University of Texas MD Anderson Cancer Center recommend intensity-modulated radiation therapy (IMRT) over 3D-conformal radiation therapy (3D-CRT) for treating locally advanced, unresectable non-small cell lung cancer (NSCLC).
Their study, published in JAMA Oncology, reveals IMRT offers comparable survival rates with fewer adverse effects compared to 3D-CRT.
The analysis of 483 patients from the Phase III NRG Oncology-RTOG 0617 randomized trial showed that those treated with 3D-CRT were significantly more likely to experience severe pneumonitis (8.2%) than those treated with IMRT (3.5%).
Lead author Dr. Stephen Chun, an associate professor of Radiation Oncology, emphasizes the need to adopt IMRT for lung cancer, as it provides better precision and spares normal tissue. While 3D-CRT directs radiation in straight lines, IMRT uses advanced methods to shape radiation to tumors, reducing unnecessary exposure to nearby organs.
The study dispels concerns about the low-dose radiation bath associated with IMRT, showing no excess secondary cancers or long-term toxicity. Patients treated with IMRT had numerically better five-year overall survival rates (30.8%) compared to 3D-CRT (26.6%), despite having larger and more complex tumors.
Furthermore, minimizing cardiac exposure during radiation is crucial. Patients with less than 20% of the heart exposed to 40 Gy had significantly better median survival (2.4 years) compared to those with more than 20% exposure (1.7 years).
Dr. Chun concluded that maximizing radiation precision to reduce cardiopulmonary exposure should be prioritized, moving past historic concerns over low-dose radiation exposure.
