Peer review for target volume quality assurance at Guy’s Cancer Centre.


Session type:


Pippa Lewis1,Renee Steel1,Teresa Guerrero Urbano1,Kathryn Innes1,Imran Hussain1,Barbara Fuller1
1Guy's and St Thomas' NHS Foundation Trust



Peer review was expanded to formally include all tumour sites at Guy’s Cancer Centre in January 2018, following published guidance from the Royal College of Radiologists recommending that “all radiotherapy departments should have processes that enable optimal target volume delineation and subsequent peer review”[1].  Peer review acts as a quality assurance mechanism for volume delineation aiming both to reduce uncertainty and to detect error.

[1] The Royal College of Radiologists. Radiotherapy Target Volume Definition and Peer Review 2017


Weekly tumour specific peer review meetings lasting 1-2 hours, depending upon caseload, are attended by a multi-disciplinary team (MDT) that includes clinicians, dosimetrists and radiographers.  Cases are discussed prospectively i.e. before the patient receives their first fraction of treatment.  Retrospective peer review takes place in some instances to avoid delay to treatment.  Virtually simulated fields are not reviewed.

Target volumes are assessed as requiring; no, minor or major revision.  Peer review outcomes are captured prospectively using an electronic proforma within the patients’ electronic health record.  Peer review outcomes were retrospectively analysed against the revision criteria.


In total 1706 radiotherapy courses commenced in the 12-month period February 2018-January 2019.  1456 (85%) of these cases had documented peer review data available.  83% of cases were discussed prospectively. Out of 1456 individual discussions at peer review, 18/1456 (1%) cases required a major revision, 128/1456 (9%) a minor revision and 1310/1456 (90%) no revision.  The overall rate of plan revision recommendations following peer review is 10%.


Peer-review meetings have become an integral part of the radiotherapy workflow and are well attended by the MDT. Our overall rate of plan revision (10%) is in line with published data and confirms that this is a necessary step in quality assurance to avoid planning-related errors or discrepancies that can ultimately impact patient safety and treatment outcomes.