Table 1 Summarised QA Team input to the development of trial documentation
From: Quality assurance of the SCOPE 1 trial in oesophageal radiotherapy
Topic | Items included in the pre-trial CR-ROM |
|---|---|
Patient preparation | Descriptions of ‘best practice’ for patient immobilisation and acquisition of the planning scan, administration of intravenous (IV) contrast and subsequent handling of contrasted images in the treatment planning system. |
Structure delineation | Written and pictorial descriptions of the method for planning target volume (PTV) generation from the gross tumour volume (GTV) via the consecutive stages of clinical target volume (CTV), (‘CTVA’ and ‘CTVB’). Margin sizes were adopted from local practice [28], with multiple CTV stages formalised to correctly account for sub-clinical spread of disease along the line of the oesophagus, radially and below the level of the gastro-oesophageal junction (GOJ). In addition, a method for discretionary posterior modification of CTVB where close to the spinal cord was included. |
Dose-volume criteria | Dose volume histogram (DVH) requirements (Table 2, column 1) for use with different types of dose calculation algorithms, namely ‘type a’ and ‘type b’ [11]. For ‘type b’, this required an investigative planning study [12], summarised later. A plan assessment form (PAF) [see Additional file 3] to maximise correct data return. Deviation levels for target coverage and OAR doses |
Single phase planning | An illustrated planning guide including four problem examples. Use of a single phase plan, which had been shown to deliver lower heart doses than a widely used two phase approach using a ‘lung sparing’ anterior-posterior pair followed by a ‘cord sparing’ three field arrangement [29, 30] was mandated. Since this was not exclusively used in the UK at the time of the trial launch [6] the planning guide sought to assist with this transition, where required. |
Treatment verification | An illustrated description of suitable pre-treatment and/or on-treatment verification processes aimed at ensuring accurate reproduction of the planned isocentre position and to manage significant changes to the patient’s external anatomy subsequent to planning. |