Intensity-modulated radiation therapy (IMRT) is commonly used for patients with prostate cancer because it allows dose escalation to the tumor while reducing radiation exposure to surrounding healthy tissues such as the bladder and rectum.1,2 This reduction may be at the expense of increased radiation exposure to more distant tissues from scatter radiation, particularly the red bone marrow, compared with the exposure from 3-dimensional conformal radiotherapy (3D-CRT), the previous standard radiotherapy technique.1 Simulation studies have suggested this reduced radiation exposure could double the risk of second primary cancers.3 To date, however, no observational studies have directly compared second cancer rates after IMRT to 3D-CRT for prostate cancer.4 We compared the risks of leukemia and myelodysplasia (of particular concern given the potentially higher bone marrow dose and because they can occur as early as 2 years after exposure5) and second solid cancers after IMRT vs 3D-CRT in a large cohort of prostate cancer patients.
Journy NMY, Morton LM, Kleinerman RA, Bekelman JE, Berrington de Gonzalez A. Second Primary Cancers After Intensity-Modulated vs 3-Dimensional Conformal Radiation Therapy for Prostate Cancer. JAMA Oncol. 2016;2(10):1368-1370. doi:10.1001/jamaoncol.2016.1368