BACKGROUND AND PURPOSE: To evaluate residual patient setup errors and daily dose variations of different less-than-daily image guidance (IG) strategies in the delivery of external beam radiotherapy for esophageal cancer. MATERIAL AND METHODS: Daily image-guided setup data for 25 consecutive esophageal cancer patients treated with helical tomotherapy were evaluated. Seven less-than-daily IG strategies with different imaging frequencies were simulated. For each IG strategy, the daily residual setup errors were calculated. Using TomoTherapy Planned Adaptive software, daily dose variations to the clinical target volume, heart, and lungs were evaluated in five representative patients. RESULTS: With 0% (60%) IG frequency, the margins required for adequate coverage of the clinical target volume were 13 mm (10 mm), 14 mm (11 mm), and 5 mm (5 mm) in the left-right, superior-inferior, and anterior-posterior directions, respectively. Even with 60% IG frequency, 10% of the fractions had more than 10% decrease in the dose level covering 95% of the target, and 14% and 13% of the fractions had more than 10% increase in total lung volume receiving at least 0.8 Gy per fraction, and heart volume receiving at least 1.2 Gy per fraction, respectively. CONCLUSION: Substantial residual setup errors would occur for treatment fractions without IG even if the most frequent less-than-daily IG strategy was to be used, which could lead to significant daily dose variations for the target volume and adjacent normal tissues. Daily image guidance is recommended throughout the course of treatment in conformal radiotherapy for esophageal cancer.
BACKGROUND AND PURPOSE: To evaluate residual patient setup errors and daily dose variations of different less-than-daily image guidance (IG) strategies in the delivery of external beam radiotherapy for esophageal cancer. MATERIAL AND METHODS: Daily image-guided setup data for 25 consecutive esophageal cancerpatients treated with helical tomotherapy were evaluated. Seven less-than-daily IG strategies with different imaging frequencies were simulated. For each IG strategy, the daily residual setup errors were calculated. Using TomoTherapy Planned Adaptive software, daily dose variations to the clinical target volume, heart, and lungs were evaluated in five representative patients. RESULTS: With 0% (60%) IG frequency, the margins required for adequate coverage of the clinical target volume were 13 mm (10 mm), 14 mm (11 mm), and 5 mm (5 mm) in the left-right, superior-inferior, and anterior-posterior directions, respectively. Even with 60% IG frequency, 10% of the fractions had more than 10% decrease in the dose level covering 95% of the target, and 14% and 13% of the fractions had more than 10% increase in total lung volume receiving at least 0.8 Gy per fraction, and heart volume receiving at least 1.2 Gy per fraction, respectively. CONCLUSION: Substantial residual setup errors would occur for treatment fractions without IG even if the most frequent less-than-daily IG strategy was to be used, which could lead to significant daily dose variations for the target volume and adjacent normal tissues. Daily image guidance is recommended throughout the course of treatment in conformal radiotherapy for esophageal cancer.
Authors: Haijian Chen; Joerg Rottmann; Stephen Sf Yip; Daniel Morf; Rony Füglistaller; Josh Star-Lack; George Zentai; Ross Berbeco Journal: Biomed Phys Eng Express Date: 2017-02-21
Authors: Peter S N van Rossum; Richard van Hillegersberg; Frederiek M Lever; Irene M Lips; Astrid L H M W van Lier; Gert J Meijer; Maarten S van Leeuwen; Marco van Vulpen; Jelle P Ruurda Journal: Eur Radiol Date: 2013-02-13 Impact factor: 5.315
Authors: Daniel Gram; André Haraldsson; N Patrik Brodin; Karsten Nysom; Thomas Björk-Eriksson; Per Munck Af Rosenschöld Journal: Radiat Oncol Date: 2020-06-10 Impact factor: 3.481
Authors: Falk Roeder; Nils H Nicolay; Tam Nguyen; Ladan Saleh-Ebrahimi; Vasilis Askoxylakis; Tilman Bostel; Felix Zwicker; Juergen Debus; Carmen Timke; Peter E Huber Journal: Radiat Oncol Date: 2014-08-29 Impact factor: 3.481