Background and purpose: Creating an individualized tissue equivalent material build-up (i.e. bolus) for electron beam radiation therapy is complex and highly labour-intensive. We implemented a new... Show moreBackground and purpose: Creating an individualized tissue equivalent material build-up (i.e. bolus) for electron beam radiation therapy is complex and highly labour-intensive. We implemented a new clinical workflow in which 3D printing technology is used to create the bolus.Material and methods: A patient-specific bolus is designed in the treatment planning system (TPS) and a shell around it is created in the TPS. The shell is printed and subsequently filled with silicone rubber to make the bolus. Before clinical implementation we performed a planning study with 11 patients to evaluate the difference in tumour coverage between the designed 3D-print bolus and the clinically delivered plan with manually created bolus. For the first 15 clinical patients a second CT scan with the 3D-print bolus was performed to verify the geometrical accuracy.Results: The planning study showed that the V85% of the CTV was on average 97% (3D-print) vs 88% (conventional). Geometric comparison of the 3D-print bolus to the originally contoured bolus showed a high similarity (DSC = 0.89). The dose distributions on the second CT scan with the 3D print bolus in position showed only small differences in comparison to the original planning CT scan.Conclusions: The implemented workflow is feasible, patient friendly, safe, and results in high quality dose distributions. This new technique increases time efficiency. (C) 2016 Elsevier Ireland Ltd. All rights reserved. Show less
Minten, M.J.; Mahler, E.; Leseman-Hoogenboom, M.M.; Broeder, A.A. den; Kloppenburg, G.; Poortmans, P.; ... ; Ende, C.H. van den 2016
Introduction. The EORTC 22922/10925 trial investigated the potential survival benefit and toxicity of elective irradiation of the internal mammary and medial supraclavicular (IM-MS) nodes Accrual... Show moreIntroduction. The EORTC 22922/10925 trial investigated the potential survival benefit and toxicity of elective irradiation of the internal mammary and medial supraclavicular (IM-MS) nodes Accrual completed in January 2004 and first results are expected in 2012. We present the toxicity reported until year 3 after treatment. Patients and methods. At each visit, toxicity was reported but severity was not graded routinely. Toxicity rates and performance status (PS) changes at three years were compared by chi(2) tests and logistic regression models in all the 3 866 of 4 004 patients eligible to the trial who received the allocated treatment. Results. Only lung (fibrosis; dyspnoea; pneumonitis; any lung toxicities) (4.3% vs. 1.3%; p < 0.0001) but not cardiac toxicity (0.3% vs. 0.4%; p = 0.55) significantly increased with IM-MS treatment. No significant worsening of the PS was observed (p = 0.79), suggesting that treatment-related toxicity does not impair patient's daily activities. Conclusions. IM-MS irradiation seems well tolerated and does not significantly impair WHO PS at three years. A follow-up period of at least 10 years is needed to determine whether cardiac toxicity is increased after radiotherapy. Show less
