CT Image management of obese patients in Radiotherapy treatment planning procedure by implementing different in-house modules developed at Nayati Medicity

Sujit Nath Sinha; Santanu Chaudhuri

Volume : VII, Issue : VIII, August - 2018

CT Image management of obese patients in Radiotherapy treatment planning procedure by implementing different in-house modules developed at Nayati Medicity

Sujit Nath Sinha, Santanu Chaudhuri

Abstract :

In radiotherapy treatment planning accurate CT data is essential. For obese patients when imaged with Diagnostic CT or even sometimes with large bore CT, complete CT data is not available creating missing tissues laterally/obliquely and thereby giving error in monitor unit dose calculation. Such incomplete data also ings in beam angulation constraints during IMRT,VMAT type planning. We have developed different modules in Matlab to tackle imaging obese patients and take appropriate measures for use in treatment planning system. The main module was developed using a line profile template match method to produce a composite CT image series for obese patients from two partial CT – one taken with patient left sided and the other with patient right sided on the CT couch. The software was implemented and tested on images with bony structures in phantom and also in actual patients with good results. Further practical pitfalls were observed during CT imaging with some heavy weight patients. Since patient treatment couch in Linear Accelerator are flat, it is mandatory to have flat couch top externally fitted on CT couch for imaging. Obese patients when scanned in CT shifted on one side many a times, a tilt of the image is observed. Such tilts due to patient weight were overcome by utilizing in-house built modules in Matlab.In our Institute the different tools were used for obese patients to acquire complete CT data sets and gave good results to be used for radiotherapy treatment planning.