ESTRO 2020 Abstract book

S472 ESTRO 2020

patients accepted the performance of the tests, which included clinical evaluation (with the NOSE scale score), rhinomanometry, olphactory testing, nasal citology and evaluation of mucociliary clearance through saccharine test. Results 5-year disease specific survival of the patients with NV-SCC primarily treated by interstitial IRT was 92.3%. No late skin or cartilaginous toxicity are observed in the IMRT-EBRT and IRT groups. Particularly, no chondrites, chondronecrosis nor septal/alar perforations were reported in the IRT group, probably because of the anatomy friendly implantation technique. The most significant differences between the groups of IMRT-EBRT and IRT as well the healthy controls emerged for the mucociliary clearance (p<0.001 at ANOVA and Student’s T test), with a doubled mean time for the transportation of the stained marker in the patients treated by EBRT than in those treated with IRT. Conclusion The results of the present study demonstrated the efficacy and the safety of IRT for the treatment of patients with early nose vestibule cancer. Probably, this technique could be the new standard for the treatment of the primary lesion in cT1 and cT2 (according to the Wang staging) NV SCCs. PO-0789 Utilising radiotherapy dose to guide 3D surgical reconstructions for mandibular osteoradionecrosis N. West 1 , N. Willis 1 , J. Adams 2 , M. Kennedy 2 , S. Iqbal 1 1 Newcastle upon Tyne Hospitals Trust, Northern Centre for Cancer Care, Newcastle upon Tyne, United Kingdom ; 2 Newcastle upon Tyne Hospitals Trust, Dental Services Directorate, Newcastle upon Tyne, United Kingdom Purpose or Objective Following radiotherapy for head and neck cancer, some patients can present with osteoradionecrosis in the mandible. This presents at 18-24m post-irradiation and often initiated by trauma or infection to the local area. The current standard of care is mandibular resection and reconstruction, using replacement bone taken from the patient's fibula (Figure 1b/c). Diagnostic scans guide surgical design, done remotely and in partnership with an implant company specialising in craniomaxillofacial reconstruction. However, osteoradionecrosis can manifest as a progressive disease with necrosis continuing after the removal of affected bone. Diagnostic CTs do not always show the full extent of osteoradionecrosis and disease can present post-surgery, which compromises the success of the original surgical procedure. Failure of this complex process is not only distressing for patients but also very expensive; procedural costs are in excess of €120,000. Material and Methods To minimise surgical failure rate, we maximise the chance of including previously irradiated mandible in the resected volumes by utilising previously delivered radiotherapy dose. This novel process begins with the mandible being contoured on the diagnostic CT and the scan deformably registered with the treatment planning CT (Figure 2a). The mandible structure on diagnostic CT is then propagated to the radiotherapy planning CT. Displaying the delivered radiotherapy dose on the diagnostic CT defined 3D mandible structure, the volume of bone irradiated to different radiotherapy dose levels is easily visualised (Figure 2b). Exporting isodose volumes as stl files to the 3D surgical design application, which is then viewed simultaneously with the 3D surgical display, aids the surgeon when remotely planning the surgery in conjunction with the surgical design company (Figure 2c/d).

rate was significantly worse in patients with locoregionally recurrent papillary thyroid carcinoma. Accordingly, to prevent distant metastasis, a more effective systemic treatment method is needed. PO-0788 Smell protocol:exclusive interventional radiotherapy in the treatment of nasal vestibule carcinomas V. Lancellotta 1 , L. Tagliaferri 2 , E. De Corso 3 , G.C. Passali 4 , G.C. Mattiucci 5 , M.A. Gambacorta 6 , D. Rizzo 7 , B. Fionda 2 , F. Deodato 8 , G. Di Cintio 9 , A. Salvati 10 , G. Paludetti 11 , V. Valentini 12 , J. Galli 11 , F. Bussu 7 1 Policlinico Agostino Gemelli, Radiation Oncology, Rome, Italy ; 2 Fondazione Policlinico Universitario A. Gemelli IRCCS- UOC di Radioterapia, Dipartimento di Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy ; 3 UOC di Otorinolaringoiatria-Fondazione Policlinico Universitario A. Gemelli IRCCS, Dipartimento Scienze dell’Invecchiamento- Neurologiche- Ortopediche e della testa collo, Rome, Italy ; 4 2UOC di Otorinolaringoiatria- Fondazione Policlinico Universitario A. Gemelli IRCCS, Dipartimento Scienze dell’Invecchiamento- Neurologiche- Ortopediche e della testa collo, Rome, Italy ; 5 Fondazione Policlinico Universitario A. Gemelli IRCCS- UOC di Radioterapia. Università Cattolica del Sacro Cuore- Istituto di Radiologia., Dipartimento di Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy ; 6 Fondazione Policlinico Universitario A. Gemelli IRCCS- UOC di Radioterapia. Università Cattolica del Sacro Cuore- Istituto di Radiologia, Dipartimento di Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy ; 7 Azienda Ospedaliero Universitaria, Divisione di otorinolaringoiatria, Sassari, Italy ; 8 Fondazione Ricerca e Cura Giovanni Paolo II- Università Cattolica del Sacro Cuore, Dipartimento di Radioterapia, Campobasso, Italy ; 9 Università Cattolica del Sacro Cuore- Policlinico Agostino Gemelli, Istituto di otorinolaringoiatria, Rome, Italy ; 10 Università Cattolica del Sacro Cuore- Policlinico Otorinolaringoiatria- Istituto di otorinolaringoiatria- Università Cattolica del Sacro Cuore- Policlinico Agostino Gemelli, Dipartimento Scienze dell’Invecchiamento- Neurologiche- Ortopediche e della testa collo. Fondazione Policlinico Universi, ; 12 Fondazione Policlinico Universitario A. Gemelli IRCCS- UOC di Radioterapia- Università Cattolica del Sacro Cuore- Istituto di Radiologia, Dipartimento di Scienze Radiologiche- Radioterapiche ed Ematologiche, Rome, Italy Purpose or Objective Squamous cell carcinoma (SCC) of the nasal vestibule (NV) is a relatively rare condition, accounts about 1% of all head and neck malignancies. Gold standard of treatment for nose vestibule SCCs remain surgery, external beam radiotherapy (EBRT) and interventional radiotherapy (IRT, BrachyTherapy BT). Functional preservation is taken currently into increasing consideration. The present work evaluated nose functional parameters comparing patients underwent interstitial IRT vs healthy controls and patients treated with intensity modulated (IMRT)-EBRT. Material and Methods We evaluated 10 consecutive previously untreated patients (group 1), affected by NV-SCC treated with interstitial IRT between 2012 and 2017, using an anatomy friendly implantation technique. The tumours were classified in 3 groups, according to the subsite of origin, namely “ala/limen nasi”, “columella/septum”, “inferior border/superior lip”. Patient and tumor characteristics are summarized in table I. This cohort was compared to 8 patients treated by IMRT-EBRT (group 2) because of NV- SCC and both groups were compared to 10 sex and age matcheable healthy subjects, with no history of rhinosinusitis or nasal symptoms (Healthy controls). All Agostino Gemelli- Rome- Italia., Istituto di otorinolaringoiatria, Rome, Italy ; 11 UOC di