Comparison of CT and integrated PET-CT based radiation therapy planning in patients with malignant pleural mesothelioma

<p>Abstract</p> <p>Background</p> <p>When combined with adequate tumoricidal doses, accurate target volume delineation remains to be the one of the most important predictive factors for radiotherapy (RT) success in locally advanced or medically inoperable malignant pleural mesothelioma (MPM) patients. Recently, 18-fluorodeoxyglucose positron emission tomography (PET) has demonstrated significant improvements in diagnosis and accurate staging of MPM. However, role of additional PET data has not been studied in RT planning (RTP) of patients with inoperable MPM or in those who refuse surgery. Therefore, we planned to compare CT with co-registered PET-CT as the basis for delineating target volumes in these patients group.</p> <p>Methods</p> <p>Retrospectively, the CT and co-registered PET-CT data of 13 patients with histologically proven MPM were utilized to delineate target volumes separately. For each patient, target volumes (gross tumor volume [GTV], clinical target volume [CTV], and planning target volume [PTV]) were defined using the CT and PET-CT fusion data sets. The PTV was measured in two ways: PTV1 was CTV plus a 1-cm margin, and PTV2 was GTV plus a 1-cm margin. We analyzed differences in target volumes.</p> <p>Results</p> <p>In 12 of 13 patients, compared to CT-based delineation, PET-CT-based delineation resulted in a statistically significant decrease in the mean GTV, CTV, PTV1, and PTV2. In these 12 patients, mean GTV decreased by 47.1% ± 28.4%, mean CTV decreased by 38.7% ± 24.7%, mean PTV1 decreased by 31.1% ± 23.1%, and mean PTV2 decreased by 40.0% ± 24.0%. In 4 of 13 patients, hilar lymph nodes were identified by PET-CT that was not identified by CT alone, changing the nodal status of tumor staging in those patients.</p> <p>Conclusion</p> <p>This study demonstrated the usefulness of PET-CT-based target volume delineation in patients with MPM. Co-registration of PET and CT information reduces the likelihood of geographic misses, and additionally, significant reductions observed in target volumes may potentially allow escalation of RT dose beyond conventional limits potential clinical benefits in tumor control rates, which needs to be tested in future studies.</p

Living with mesothelioma. A literature review.

Mesothelioma is an asbestos-related cancer that affects mainly the pleura. World-wide incidence is increasing and set to rise for some time particularly in developing countries. Mesothelioma is uniformly fatal and often associated with difficult symptoms. The purpose of this review is to identify what is known about the experience of people living with mesothelioma. A literature search identified 13 papers covering qualitative studies, patient-reported quality of life data collected as part of a clinical trial, symptoms and survey of patients and carers. The findings suggest the impact of mesothelioma is multidimensional on: physical symptoms (especially pain, breathlessness, fatigue, cough, sleep disturbance, appetite loss and sweating), emotional functioning (anxiety, depression, fear and isolation), social consequences (changes in roles and relationships) and interventions (the necessity of frequent anti-cancer treatments and admissions for symptom control). The impact on family members is significant also. Although limited, these findings provide an important insight into the impact of mesothelioma on patients and family members and suggest areas where service provision may fail to meet their needs. Finally, the review highlights an urgent need for further research to more fully understand the experience of living with mesothelioma and identify the specific needs of patients and family members