This is a topic that I recently heard a talk about in my residency program. I will pass on the relevant Radiation Oncology info...
The great news is that Radiation Oncologists have one of the lowest malpractice insurance rates of all fields in medicine. This may seem paradoxical, since we treat severely ill patients with a medium that is potentially very toxic. The reason that we are spared this significant malpractice litigation is because of the way that attorneys and insurance companies calculate liability. The amount of potential liability in a case is a function of the amount of lost life or productivity endured by a patient as a result of a physicians error, or the severity and length of morbidity. Also calculated are the cost of subsequent medical treatments resulting from said error. The most common reasons for large malpractice suits in the United States are for MISSED diagnoses of Breast, Prostate, Cervical, Lung or Colon Cancer (especially in young patients) and for missed pulmonary embolisms in young women on OCPs. Fortunately for the radiation oncologist, our patients typically have a tissue diagnoses of cancer by the time they get to our office. The life expectancy of a person with any of the above cancer (save maybe prostate) is low, and their expected morbidity from their primary disease is high, regardless of their age or the efficacy of treatment. As a result, there are inherent limitations on the amount of potential monetary loss based on the above formula used by attorneys and insurance providers. Therefore, it is our responsibility to treat the patient reasonably based on up to date information, with attention to limitting dose to radiosensitive structures like the spinal cord, brainstem and optic nerve. If we fulfill this responsibility our liability is minimal.
It is sometimes difficult for us to understand malpractice, since we don't think like lawyers. Hope this helps clear the grey about this issue...