Auto-segmentation of head and neck organs at risk in radiotherapy and its dependence on anatomic similarity
- Author:
Anantharaman AYYALUSAMY
1
;
Subramani VELLAIYAN
;
Shanmuga SUBRAMANIAN
;
Arivarasan ILAMURUGU
;
Shyama SATPATHY
;
Mohammed NAUMAN
;
Gowtham KATTA
;
Aneesha MADINENI
Author Information
- Publication Type:Original Article
- Keywords: Head and neck cancer; Radiotherapy planning; Organs at risk
- MeSH: Brain Stem; Head and Neck Neoplasms; Head; Humans; Larynx; Mandible; Methods; Mouth; Neck; Organs at Risk; Pharyngeal Muscles; Radiotherapy; Spinal Cord; Trachea
- From:Radiation Oncology Journal 2019;37(2):134-142
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: The aim is to study the dependence of deformable based auto-segmentation of head and neck organs-at-risks (OAR) on anatomy matching for a single atlas based system and generate an acceptable set of contours. METHODS: A sample of ten patients in neutral neck position and three atlas sets consisting of ten patients each in different head and neck positions were utilized to generate three scenarios representing poor, average and perfect anatomy matching respectively and auto-segmentation was carried out for each scenario. Brainstem, larynx, mandible, cervical oesophagus, oral cavity, pharyngeal muscles, parotids, spinal cord, and trachea were the structures selected for the study. Automatic and oncologist reference contours were compared using the dice similarity index (DSI), Hausdroff distance and variation in the centre of mass (COM). RESULTS: The mean DSI scores for brainstem was good irrespective of the anatomy matching scenarios. The scores for mandible, oral cavity, larynx, parotids, spinal cord, and trachea were unacceptable with poor matching but improved with enhanced bony matching whereas cervical oesophagus and pharyngeal muscles had less than acceptable scores for even perfect matching scenario. HD value and variation in COM decreased with better matching for all the structures. CONCLUSION: Improved anatomy matching resulted in better segmentation. At least a similar setup can help generate an acceptable set of automatic contours in systems employing single atlas method. Automatic contours from average matching scenario were acceptable for most structures. Importance should be given to head and neck position during atlas generation for a single atlas based system.
