New Radiotherapy Technique May be Safer for Mesothelioma

There’s more evidence that an advanced method for delivering radiotherapy may improve survival for mesothelioma patients after surgery.

Extrapleural pneumonectomy (EPP) is a surgical procedure for malignant pleural mesothelioma that involves removing the mesothelioma tumor, as well as the pleural lining where the tumor is located, the nearest lung, all or part of the diaphragm, and other internal membranes. It is often followed by adjuvant radiotherapy to kill remaining tumor cells.

Because the radiation target area in post-operative mesothelioma patients is irregular in shape and located close to critical internal organs, many patients receive a targeted type of radiotherapy called intensity modulated radiation therapy (IMRT). But postoperative IMRT also carries a high risk of a potentially fatal lung condition called pneumonitis. The toxicity can be even worse if the mesothelioma patient is also receiving chemotherapy.

Now a team of Japanese doctors believes there may be a better, safer way to deliver IMRT for mesothelioma. The team reports that delivering hemithoracic (in the chest cavity) IMRT using helical tomotherapy appears to produce good results with fewer side effects. A marriage of spiral CT-scanning technology and IMRT, helical tomotherapy offers enhanced precision and the ability to direct the same amount of radiation into the tumor from multiple angles at once, minimizing the damage to surrounding tissue.

For three mesothelioma patients who had had EPP, a radiation dose of 45 Gy was given in 25 fractions using helical tomotherapy. The treatment covered 95 percent of the region where the tumor had been. When the patients were followed up at 26, 14 and 9 months, all were still alive, although one patient had had a recurrence of the mesothelioma. None of the patients developed pneumonitis.

Although the study size was very small, the researchers explained that they were anxious to report their results since the technique may benefit other patients. “Hemithoracic IMRT using helical tomotherapy may play a crucial role in adjuvant treatment for malignant pleural mesothelioma after EPP,” they write in a summary of their experience. The report was published in the Journal of Radiation Research.

Sources:

Ebara, T et al, “Hemithoracic Intensity-modulated Radiotherapy Using Helical Tomotherapy for Patients after Extrapleural Pneumonectomy for Malignant Pleural Mesothelioma”, February 25, 2012, Journal of Radiation Research (Tokyo), Epub ahead of print. Chi, A et al, “Intensity-modulated radiotherapy after extrapleural pneumonectomy in the combined-modality treatment of malignant pleural mesothelioma”, June 6, 2011, Journal of Thoracic Oncology, pp. 1132-41