ESTRO 38 Abstract book

S863 ESTRO 38

No residual pain has been scored at the site of irradiation. A clinical complete response was observed in 95.7% of cases at 3 months, 2 patient presented residual disease at 3 months. After a median follow up of 6 months (1-21 months), local control rate is 95.6%: 1 patient experienced in-field recurrence at 6 months and one patient marginal recurrence at 4 months. Conclusion Our preliminary results show that EBT is an effective, simple, safe, and comfortable treatment associated with good cosmetic outcomes for non-melanoma skin cancers. Even if a longer follow-up and a bigger sample size are needed to confirm these preliminary findings, EBT can be an alternative solution for elderly pts, for pts refusing or presenting contraindications for surgery or when surgical treatment would result in a more disfiguring outcome. EP-1600 Implementing TG100: an FMEA for superficial radiotherapy at Wellington Blood and Cancer Centre A. Williams 1 , B. Steer 1 , D. Paterson 1 , J. Evans 1 , R. Dew 1 1 Wellington Blood and Cancer Centre, Radiation Oncology, Wellington, New Zealand Purpose or Objective Prospective risk analysis is recommended in radiotherapy to identify high risks and implement safety interventions before adverse events occur [1-4]. In this project, a multidisciplinary team (MDT) conducted a Failure Modes and Effects Analysis (FMEA) for superficial radiotherapy (SXR) with the aim to identify risks in our SXR process and to recommend safety interventions for the highest risks. The process for SXR treatments has marked differences to that for MV photon treatments, for example, patient immobilisation is limited, there is no computerised planning on CT datasets, and there is no on-board imaging during treatment, so the results of the FMEA were expected to differ considerably from those of an advance linac-based technique such as IMRT as presented in TG 100 [1]. Material and Methods We followed our department’s own FMEA procedure, closely based on that of Ford [5]. It was planned that the MDT meet six times to perform the FMEA: 1) a general FMEA education session, 2) generate the SXR process map, 3) identify possible failure modes (FMs), 4) generate risk priority number (RPN) scores for identified FMs (all FMs were scored twice by different team members), 5) group review of FM scoring, 6) develop safety recommendations. Results In total, 220 FMs were identified, of which 24 had an RPN greater than 300 (Figure 1) for which the team recommended 27 safety interventions. The recommendations were grouped according to TG100’s Table III, Ranking of QM tools based on effectiveness as shown in table 1.The top three scoring FMs were 1) Lesion extends into hairline and difficulty seeing the margin, 2) plan parameters and treatment time checked incorrectly and 3) shielding not in place when marking up GTV e.g. under lip, so wrong GTV delineated. The recommended safety interventions for these FMs were 1) hair to be removed from lesion, 2) replace one manual treatment time calculation with a Radcalc QC check, do a reverse treatment time calculation, and scan-in the contour of irregularly shaped cut-outs to a computer for automated equivalent square calculation, and 3) mark-up GTV with shielding / cut-out / applicator in place.

5 - Rules and policies

6 (6) 2 (2)

6 - Education and information

Conclusion The FMEA has facilitated a better understanding of the risks in the SXR process, however, it was time-consuming, requiring around ten hours of meetings (with four more meetings than planned) and many hours of supplementary work outside of the meetings. Listing FMs was challenging and their scoring highly subjective, and some of the recommended interventions e.g. a move to electronic prescribing, will affect our whole radiotherapy service, not just the SXR process. The recommended interventions for failure modes scoring greater than 300 are now being reviewed by senior management with a view to their implementation.

Electronic Poster: Clinical track: Sarcoma

EP-1601 Radiotherapy in resectable Intrathoracic Sarcomas. A Rare Cancer Network Study C. Solé 1 , F. Larsen 2 , M. Terlizzi 3 , P. Sargos 3 , V. Linacre 4 , F. Suarez 5 , Y. Kirova 6 , P. Van Houtte 7 , D. Lerouge 8 , T. Zilli 9 1 Instituto de Radiaciones Médicas, Radiotherapy, Santiago, Chile ; 2 Clinica IRAM, Santiago, Chile ; 3 Institut Bergonie, Bordeaux, France ; 4 Instituto Nacional del Torax, Thoracic Surgery, Santiago, Chile ; 5 Clinica Santa Maria, Thoracic Surgery, Santiago, Chile ; 6 Institut Curie, Paris, France ; 7 Institut Bordet, Bruxelles, Belgium ; 8 Centre Baclesse, Caen, France ; 9 Hôpitaux Universitaires de Genève, Geneva, Switzerland Purpose or Objective Intrathoracic sarcomas (ITS) are considered rare tumors and have a dismal prognosis. We investigated outcomes and risk factors for local control (LC), disease free survival (DFS) and overall survival (OS) in patients with resected non- metastatic ITS treated with or without adjuvant radiotherapy (RT) and or chemotherapy (CT). Material and Methods

Table 1. Number of interventions grouped according to effectiveness as per TG 100 Table III QM Tools

of

Number

interventions (FMs)

1 - Forcing functions

0

2 - Automation and computerisation 3 - Protocols, standards and information 4 - Independent double check systems

5 (9)

13 (18)

1 (3)