Dose control in radiotherapy cancer treatment: improving dose coverage with estimation and feedback

Since the late nineteenth century, physicians have prescribed external X-ray radiation to destroy or impede the growth of cancerous tumors. This treatment is known as radiation therapy or radiotherapy. Traditionally, the applied radiation beam has a uniform intensity, but recent computing and medical advances have prompted the growth of intensity-modulated radiation therapy in which a non-uniform radiation beam is applied to the tumor. A non-uniform beam allows the radiation dose to more precisely conform to the specific geometry of the tumor, improving the overall success of the treatment. However, two factors are inhibiting the potential gains of intensity-modulated radiation therapy: tumor motion during the treatment, and errors in aligning the patient with the radiation beam. Extending recent results, this paper proposes a feedback scheme to track the tumor during the treatment, overcoming these hurdles