Sun Hyun Bae1, Mi-Sook Kim2, Won Il Jang2, Kum Bae Kim2, Kwang Hwan Cho1, Woo Chul Kim3, Chang Yeol Lee3, Eun Seog Kim4, Chul Won Choi5, A Ram Chang6, Sunmi Jo7, Jin-Young Kim7. 1. Department of Radiation Oncology, Soonchunhyang University College of Medicine, Bucheon. 2. Department of Radiation Oncology, Korea Institute of Radiological & Medical Sciences, Seoul. 3. Department of Radiation Oncology, Inha University Hospital, Inha University School of Medicine, Incheon. 4. Department of Radiation Oncology, Soonchunhyang University College of Medicine, Cheonan. 5. Department of Radiation Oncology, Dongnam Institute of Radiological & Medical Sciences, Busan. 6. Department of Radiation Oncology, Soonchunhyang University College of Medicine, Seoul. 7. Department of Radiation Oncology, Haeundae Paik Hospital, Inje University School of Medicine, Busan, South Korea.
Abstract
OBJECTIVE: The Korean Radiation Oncology Group (12-02) investigated the outcome of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm using 60 Gy in three fractions. To evaluate dosimetric differences and compliance in a multicenter trial, a planning dummy run procedure was performed. METHODS: All six participating institutions were provided the contours of two dummy run cases. Plans were performed following the study protocol to cover the planning target volume with a minimum of 90% of the prescription dose and to satisfy the constraints for organs at risk. We assessed the institutional variations in plans using dose-volume histograms. RESULTS: Different planning techniques were applied: static intensity-modulated radiotherapy in two institutions, CyberKnife in two institutions and RapidArc in two institutions. The conformity index of all 12 plans was ≤1.2. In terms of the planning target volume coverage, all participants followed our study protocol. For the second dummy run case, located in Segment 8 near the heart, the minimum dose of the planning target volume (D99%: dose covering 99% of the planning target volume) was variable because there was no mention of constraints of D99% of the planning target volume in the study protocol. As an important organ at risk, the normal liver volumes receiving <17 Gy in all 12 plans were >700 ml. CONCLUSIONS: Dosimetric parameters showed acceptable compliance with the study protocol. However, we found the possibility of underdose to the planning target volume if the hepatocellular carcinoma lesion was located near organs at risk such as the heart. Based on this dummy run, we will conduct individual case reviews to minimize the effects of study protocol deviation.
OBJECTIVE: The Korean Radiation Oncology Group (12-02) investigated the outcome of stereotactic ablative radiotherapy for hepatocellular carcinoma ≤5 cm using 60 Gy in three fractions. To evaluate dosimetric differences and compliance in a multicenter trial, a planning dummy run procedure was performed. METHODS: All six participating institutions were provided the contours of two dummy run cases. Plans were performed following the study protocol to cover the planning target volume with a minimum of 90% of the prescription dose and to satisfy the constraints for organs at risk. We assessed the institutional variations in plans using dose-volume histograms. RESULTS: Different planning techniques were applied: static intensity-modulated radiotherapy in two institutions, CyberKnife in two institutions and RapidArc in two institutions. The conformity index of all 12 plans was ≤1.2. In terms of the planning target volume coverage, all participants followed our study protocol. For the second dummy run case, located in Segment 8 near the heart, the minimum dose of the planning target volume (D99%: dose covering 99% of the planning target volume) was variable because there was no mention of constraints of D99% of the planning target volume in the study protocol. As an important organ at risk, the normal liver volumes receiving <17 Gy in all 12 plans were >700 ml. CONCLUSIONS: Dosimetric parameters showed acceptable compliance with the study protocol. However, we found the possibility of underdose to the planning target volume if the hepatocellular carcinoma lesion was located near organs at risk such as the heart. Based on this dummy run, we will conduct individual case reviews to minimize the effects of study protocol deviation.