Fine tuning the amount of radioactivity to deliver to cancerous tissue is a persistent challenge since too much radiation will do unnecessary damage to healthy tissue, while not enough won’t kill the tumor. Estimates and simulations can be done, but they can be inaccurate, so a new approach of actually creating phantoms of individual patients’ organs before radiotherapy is now being used to get better results.
The phantoms created by The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust are 3D printed out of plastic and are modeled closely on imaging scans of the relevant organs taken prior to the delivery of therapy. The phantoms are injected with the same radioactive compounds used for therapy and their exposure to radioactivity is monitored. This provides an accurate representation of the levels of radioactivity that is reaching different parts of the phantom and gives a good idea of how the actual tumor and healthy tissue around it will be affected in the patient.