Quality assurance of the EORTC trial 22881/10882: "assessment of the role of the booster dose in breast conserving therapy": the Dummy Run. EORTC Radiotherapy Cooperative Group.
The EORTC trial 22881/10882 is a randomised trial with the aim to assess the role of the boost dose in breast conserving therapy in stage I and II breast cancer. In order to detect potential protocol deviations concerning irradiation technique and in the dose specification procedure of participating institutions before actual patient accrual, a Dummy Run was performed. Three transverse sections of a patient were sent to 16 participating institutions with a request to make a three-plane treatment plan according to the protocol prescriptions. A treatment chart and beam data were also requested for recalculation of the dose. Additional information was asked in a questionnaire. On evaluation, the techniques differed considerably with respect to photon beam energy, varying between 60Co gamma-rays and 8 MV X-rays, and the use of wedge filters. Two institutions did not apply wedges, whereas wedge angles in the other institutions varied between 6 degrees and 45 degrees. Twelve institutions used collimator rotation and/or a table wedge to diminish the amount of irradiated lung volume. The dose was specified in a point according to the protocol prescription in 11 institutions and to the 90, 95 or 100% isodose curve in four. Twelve institutions applied lung density corrections during treatment planning, while nine reported problems with their planning system in off-axis dose distribution calculation and/or the simulation of collimator rotation. Recalculation of the dose at the isocentre showed agreement within 2% compared with the stated dose. The dose reported in the tumour excision area varied between 93 and 100%.(ABSTRACT TRUNCATED AT 250 WORDS)
van Tienhoven
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G
Radiotherapy Department, Netherlands Cancer Institute (Antoni van Leeuwenhoek Huis), Amsterdam.
van Bree
N A
NA
Mijnheer
B J
BJ
Bartelink
H
H
D001943:Breast Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D004307:Dose-Response Relationship, Radiation; D005060:Europe; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D011184:Postoperative Period; D011785:Quality Assurance, Health Care; D011879:Radiotherapy Dosage