Management of CT image for obese patients in radiotherapy treatment planning procedure

In radiotherapy treatment planning accurate CT data is essential. Computer tomography imaging has become mandatory for treatment planning in Radiotherapy. For obese patients when imaged with Diagnostic CT or even sometimes with large bore CT in the range 80 to 85 cm, corresponding image reconstruction FOV ranges between 50 cm to 65 cm. This implies that even if an obese patient is accommodated in the scanner, the CT data may have truncated image due to limitation in FOV size. The complete CT data is not available creating missing tissues laterally/obliquely where radiation beam path cannot be accurately derived due to lack of CT data and thereby giving error in monitor unit dose calculation