A System for Continual Quality Improvement of Normal Tissue Delineation for Radiation Therapy Treatment Planning

• Published in: International journal of radiation oncology, biology, physics Vol. 83; no. 5; pp. e703 - e708
• Main Authors: Breunig, Jennifer, CMD, MS, Hernandez, Sophy, MD, Lin, Jeffrey, BS, Alsager, Stacy, CMD, Dumstorf, Christine, CMD, Price, Jennifer, CMD, Steber, Jennifer, CMD, Garza, Richard, MD, Nagda, Suneel, MD, Melian, Edward, MD, Emami, Bahman, MD, Roeske, John C., PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-08-2012
• Subjects: Abdominal Neoplasms - diagnostic imaging; Abdominal Neoplasms - radiotherapy; BRAIN; Brain Neoplasms - diagnostic imaging; Brain Neoplasms - radiotherapy; CAT SCANNING; CHEST; COMPARATIVE EVALUATIONS; Contouring; ESOPHAGUS; Feasibility Studies; Female; HEAD; Head and Neck Neoplasms - diagnostic imaging; Head and Neck Neoplasms - radiotherapy; Hematology, Oncology and Palliative Medicine; Humans; Male; MEDICAL PERSONNEL; METRICS; NECK; NEOPLASMS; Neoplasms - diagnostic imaging; Neoplasms - radiotherapy; NERVES; Normal tissue delineation; Organs at Risk - diagnostic imaging; PANCREAS; PATIENTS; Pelvic Neoplasms - diagnostic imaging; Pelvic Neoplasms - radiotherapy; PLANNING; PROSTATE; QUALITY ASSURANCE; Quality Improvement; RADIATION DOSES; Radiation Injuries - prevention & control; Radiography; Radiology; RADIOLOGY AND NUCLEAR MEDICINE; RADIOTHERAPY; Radiotherapy Planning, Computer-Assisted - methods; Radiotherapy Planning, Computer-Assisted - standards; RECOMMENDATIONS; TESTING; Thoracic Neoplasms - diagnostic imaging; Thoracic Neoplasms - radiotherapy; Contouring; Quality assurance; Normal tissue delineation
• DOI: 10.1016/j.ijrobp.2012.02.003
• EISSN: 1879-355X
• ISSN: 0360-3016

Purpose To implement the “plan-do-check-act” (PDCA) cycle for the continual quality improvement of normal tissue contours used for radiation therapy treatment planning. Methods and Materials The CT scans of patients treated for tumors of the brain, head and neck, thorax, pancreas and prostate were selected for this study. For each scan, a radiation oncologist and a diagnostic radiologist, outlined the normal tissues (“gold” contours) using Radiation Therapy Oncology Group (RTOG) guidelines. A total of 30 organs were delineated. Independently, 5 board-certified dosimetrists and 1 trainee then outlined the same organs. Metrics used to compare the agreement between the dosimetrists' contours and the gold contours included the Dice Similarity Coefficient (DSC), and a penalty function using distance to agreement. Based on these scores, dosimetrists were re-trained on those organs in which they did not receive a passing score, and they were subsequently re-tested. Results Passing scores were achieved on 19 of 30 organs evaluated. These scores were correlated to organ volume. For organ volumes <8 cc, the average DSC was 0.61 vs organ volumes ≥8 cc, for which the average DSC was 0.91 ( P =.005). Normal tissues that had the lowest scores included the lenses, optic nerves, chiasm, cochlea, and esophagus. Of the 11 organs that were considered for re-testing, 10 showed improvement in the average score, and statistically significant improvement was noted in more than half of these organs after education and re-assessment. Conclusions The results of this study indicate the feasibility of applying the PDCA cycle to assess competence in the delineation of individual organs, and to identify areas for improvement. With testing, guidance, and re-evaluation, contouring consistency can be obtained across multiple dosimetrists. Our expectation is that continual quality improvement using the PDCA approach will ensure more accurate treatments and dose assessment in radiotherapy treatment planning and delivery.