Incorporating quantitative single photon emission computed tomography into radiation therapy treatment planning for lung cancer: impact of attenuation and scatter correction on the single photon emission computed tomography-weighted mean dose and functional lung segmentation.

PURPOSE: To assess the impact of attenuation and scatter corrections on the calculation of single photon emission computed tomography (SPECT)-weighted mean dose (SWMD) and functional volume segmentation as applied to radiation therapy treatment planning for lung cancer. METHODS AND MATERIALS: Nine patients with lung cancer underwent a SPECT lung perfusion scan. For each scan, four image sets were reconstructed using the ordered subsets expectation maximization method with attenuation and scatter corrections ranging from none to a most comprehensive combination of attenuation corrections and direct scatter modeling. Functional volumes were segmented in each reconstructed image using 10%, 20%, …, 90% of maximum SPECT intensity as a threshold. Systematic effects of SPECT reconstruction methods on treatment planning using functional volume were studied by calculating size and spatial agreements of functional volumes, and V(20) for functional volume from actual treatment plans. The SWMD was calculated for radiation beams with a variety of possible gantry angles and field sizes. RESULTS: Functional volume segmentation is sensitive to the particular method of SPECT reconstruction used. Large variations in functional volumes, as high as >50%, were observed in SPECT images reconstructed with different attenuation/scatter corrections. However, SWMD was less sensitive to the type of scatter corrections. SWMD was consistent within 2% for all reconstructions as long as computed tomography-based attenuation correction was used. CONCLUSION: When using perfusion SPECT images during treatment planning optimization/evaluation, the SWMD may be the preferred figure of merit, as it is less affected by reconstruction technique, compared with threshold-based functional volume segmentation.

Sinonasal undifferentiated carcinoma: case series and systematic review of the literature.

Sinonasal undifferentiated carcinoma is a rare, highly aggressive malignancy. A number of case series have been published in the literature. Most authors recommend aggressive management with a combination of surgery, radiotherapy, and chemotherapy, but the numbers in the individual studies are too small to produce a definitive opinion on the standard of care. In an attempt to determine the optimal treatment for this condition, we have undertaken a systematic review of the literature to evaluate all cases of sinonasal undifferentiated carcinoma that have been published since its initial description in 1986. Patient demographics, extent of the tumour at presentation, management, and outcomes were evaluated. We also present the experience from our institution.

Cancer and chemotherapy-related upper gastrointestinal symptoms: the role of abnormal gastric motor function and its evaluation in cancer patients.

Disorders of gastric emptying are being increasingly recognized as the basis for "functional" symptoms in the general population. Recent research suggests that abnormal gastric emptying may also be the cause of common gastrointestinal problems in those with cancer, and can be a complication both of the disease and of its treatment. These disorders are diagnosed by measuring the rate of gastric emptying and comparing it with the normal rate. There are numerous methods of measurement available, each with inherent advantages and disadvantages. Differences in method application and a lack of standardization limit the extent to which results from different institutions can be compared. Because of the limitations of existing methods, new technology is frequently being evaluated. Radionuclide measurement is the current method of choice.