New Program May Predict Mesothelioma Radiotherapy Response

Doctors at a cancer research facility in Germany have recently tested a new way to help clinicians plan and predict outcomes for mesothelioma patients who have radiotherapy.

One of the most difficult aspects of treating mesothelioma is creating an individualized treatment plan from the few available treatment options. Because mesothelioma tends to grow rapidly – often claiming lives within a year of diagnosis – it is crucial that doctors quickly choose the therapy combination that is most likely to produce results.

Doctors investigating a new prognostic computer program at the German Cancer Research Center in Heidelberg say the program produces a visual representation that may make mesothelioma treatment planning easier. Using population-based dose response curves and the  prescribed dose as the common dosimetric variable, the program creates histograms that can both predict the likelihood that radiotherapy will control the individual’s pleural mesothelioma tumor (tumor control probability – TCP) and the likelihood that it will damage normal tissue (normal tissue complication probability – NTCP). Uncertainties in both of these areas are related to dosing variations and differences in the radiosensitivity of individual mesothelioma patients.

In a report on the software in an Italian medical journal, the team used a pleural mesothelioma case to demonstrate how it could be used in practice. In the sample case, a prescribed dose of 54 Gy together with radiosensitivity variations of 6% for the tumor and 10% for the normal tissue produced a TCP of 85% and an NTCP of 4%. The testers went on to demonstrate how the histograms would change if the radiosensitivity of the tumor and/or the tolerance of the healthy lung tissue was increased or decreased or if the dose was changed. They concluded that the program “can help the clinician to assess the treatment plan for the individual patient.”

Caused by exposure to asbestos, mesothelioma is a rare but virulent cancer. Although asbestos has been banned in more than 55 countries, mesothelioma continues to be a worldwide problem. While the U.S. has seen a slow decline in mesothelioma rates, mesothelioma rates are still rising in Australia, England, Asia and a number of third world countries.

Sources:

Zhang, L et all, “A method to visualize the uncertainly of the prediction of radiobiological models”, December 20, 2012, Physica Medica, Epub ahead of print.