From model-based dose computation to tomotherapy

This paper describes the first years of what became known as the Tomotherapy Research Group at the Department of Medical Physics at the University of Wisconsin-Madison (UW). The group's roots were in algorithm and software development for radiation therapy dose calculations. The concept of helical tomotherapy sprang from the design of a treatment unit which could make the computation easier which in turn created a treatment unit that created the capability to do image-guided radiotherapy. The paper discusses the genesis of our concepts and some of the difficulties encountered along the way.

Electronic brachytherapy--current status and future directions

In the past decade, electronic brachytherapy (EB) has emerged as an attractive modality for the treatment of skin lesions and intraoperative partial breast irradiation, as well as finding wider applications in intracavitary and interstitial sites. These miniature X-ray sources, which operate at low kilovoltage energies (<100 kV), have reduced shielding requirements and inherent portability, therefore can be used outside the traditional realms of the radiotherapy department. However, steep dose gradients and increased sensitivity to inhomogeneities challenge accurate dosimetry. Secondly, ease of use does not mitigate the need for close involvement by medical physics experts and consultant oncologists. Finally, further studies are needed to relate the more heterogeneous dose distributions to clinical outcomes. With these provisos, the practical convenience of EB strongly suggests that it will become an established option for selected patients, not only in radiotherapy departments but also in a range of operating theatres and clinics around the world.