Quality assurance of modern radiotherapy techniques in prostate cancer treatment

Abstract

Prostate cancer is one of the most prevalent malignant diseases that occur among men with a new case diagnosed every 2.2 min, affecting one in six men their lifetime. Radiotherapy has been a vital part of the treatment of prostate cancer with three-dimensional conformal radiotherapy (3DCRT) as the historical standard. By utilizing techniques such as intensity-modulated radiation therapy (IMRT) or volumetric modulated arc therapy (VMAT) with image-guided radiotherapy (IGRT), the amount of normal tissue treated can be reduced and thus limit this increased toxicity. These types of treatments use the multi-leaf collimator to create a sequence of small apertures to deliver a high dose to the tumor. The treatment plans are created so that a high dose is given to the target while keeping dose to organs at risk low. This requires a treatment planning system (TPS) that has the capabilities of inverse planning to generate such treatment fields. The inverse planning engine uses as input contours of the targets and OARs to generate an optimal plan. With new technologies comes a new set of quality assurance (QA) tasks that need to be performed to ensure that what is being planned in the TPS is actually what is delivered to the patient. In this chapter, we will encompass the simulation, planning, and treatment of tumors located in the prostate region. In addition we will discuss the QA methods of each component of the radiation therapy process when treating tumors in the prostate region.