Comparison of Heuristic Evaluation and Think Aloud Methods A Study in Radiotherapy Contouring Software

During the radiotherapy planning process patient’s medical images are used to determine the optimum configuration of radiation beams for their cancer treatment. The primary aim of radiotherapy planning is to maximize radiation dose to the patient’s tumour while sparing their normal tissues. To achieve this, the boundary of the tumour needs to be accurately identified in the treatment planning process, especially in the step of target volume delineation. Clinically, tumour delineation is performed by physicians, either manually or using semi-automatic/automatic software based on the patient’s CT, PET and/or MRI images. In addition to the expertise of the physician and choices of segmentation algorithms, the usability of the software also plays an important role in the tumour delineation process. In this paper, the usability of the IPLAN® contouring software was evaluated. First, two evaluators assessed the software according to the heuristic evaluation method. Then three physicians evaluated the same syste...