ESTRO 2022 - Abstract Book

S1219

Abstract book

ESTRO 2022

Results There were 61 treatments 51% performed with Axxent and 49% with Therapax.

No statistically significant differences were found between Axxent and Therapax in terms of sex distribution (men 57% and 52% respectively), mean age (84.3 and 85.3 years), type of histology basal cell (77% and 80%), squamous (13% and 20%) and lymphoma (5% and 0%). No differences were also found in terms of their main locations: nasal (32% and 37%), fronto-parietal (29% and 27%) and malar (13% and 10%). Differences were found between the total mean dose in both groups (p= 0.00) 41.06 Gy Axxent and 50.67 Gy Therapax as well as the equivalent biological dose 52.06 Gy and 67.03 Gy respectively (p= 0.00). No differences were found in the degree of toxicity observed between Axxent and Therapax presenting radiodermatitis at the end of treatment G2 in 16% and 20% (P= 0.69) and G3 in 16% and 3% respectively (p=0.09). No correlation was found either between BED or EQD2 with respect to the degree of toxicity. Regarding the observed clinical pathological response, no differences were found (P=0.83) between treatments with a percentage of complete response of 74% and 83% respectively. Conclusion Both superficial low energy photon radiotherapy and superficial electron brachytherapy are effective and well tolerated treatments in non-melanoma skin cancer with radical intent. D.V.S. Praveen 1 , G. Shyam 1 , V. Pareek 1 , S. Shishak 1 , M. Barthwal 1 , S. Pandey 1 , S. Nirala 1 , S. Sanyal 1 , J. Pattanaik 1 , S.K. Samala 1 , M.S. Tanwar 1 , S. Mandal 1 , A. A 1 , D. Bora 1 , A. Ravi 1 , V. Ghosh 1 , A.P. Solanki 1 , R. Sisodiya 1 , E. Dhamija 2 , S. Rastogi 3 , A. Barwad 4 , D.N. Sharma 1 , R. Pandey 1 1 IRCH,AIIMS, Radiation Oncology, NEW DELHI, India; 2 IRCH,AIIMS, Radiology, NEW DELHI, India; 3 IRCH,AIIMS, Medical Oncology, NEW DELHI, India; 4 IRCH,AIIMS, Pathology, NEW DELHI, India Purpose or Objective Renal primitive neuro-ectodermal tumour (rPNET)is a rare subset of extra skeletal ewings and presents as an aggressive clinical course and worse outcomes. We present our experience in the management of rPNET in terms of the clinical outcomes. Materials and Methods Between June 2012 and June 2021, patient information was retrospectively evaluated and a total of 12 patients were assessed in terms of the disease characteristics, treatment delivered, clinical and toxicity outcomes. The survival outcomes were noted in the predefined proforma. Results With a median follow up 12 months among the patient cohort, majority of them were males (8/12; 66.7%) with a median age of 29.6 years (range 18 – 51 years). Among the presentations, flank pain and haematuria constituted the bulk of symptoms. The median tumor size was 12.6 cm (range, 4.8-26.4 cm). EWSR1 positivity was found in 6 patients and negative in 2 among the total 8 patients who were tested. The most common sites for metastases were bone, lung and liver with 6 patients presenting with distant metastases. Seven patients received neoadjuvant chemotherapy with VAC and the rest received it after surgery. Radiotherapy was given in six patients. On assessing the survival, 6 patients were alive and 5 died due to the disease metastases and one due to chemotoxicity. The median survival was 18.1 months. Conclusion Renal PNETs are chemotherapy sensitive disease entity and radiation seems to play a role in multimodality treatment which combined with surgery can provide improved local control. The tumour is aggressive in nature with local recurrence and distant metastases. We need prospective studies to better understand the role of treatment modalities and the clinical outcomes. PO-1437 Clinical outcomes in adult primitive neuro-ectodermal tumor of kidney: A single institute experience

PO-1438 Adjuvant radiotherapy after salvage surgery for recurrent nodal melanoma

L.H. Holtkamp 1,2 , S.N. Lo 1,3 , J.F. Thompson 1,3,4 , O.E. Nieweg 1,3,4 , A.M. Hong 1,3

1 The University of Sydney, Melanoma Institute Australia, Sydney, Australia; 2 University Medical Center Groningen, Department of Surgical Oncology, Groningen, The Netherlands; 3 The University of Sydney, Faculty of Medicine and Health, Sydney, Australia; 4 Royal Prince Alfred Hospital, Department of Melanoma and Surgical Oncology, Sydney, Australia Purpose or Objective Adjuvant radiotherapy (RT) to a regional lymph node field has a potential role following an initial elective lymph node dissection in high-risk stage III melanoma patients, but is also used after resection of a node field recurrence following a prior node dissection. The efficacy of RT in these two clinical scenarios may differ. In the second scenario, where the tumour biology may have become more aggressive, the value of adjuvant RT is less evident. The purposes of this study were to determine node field control and recurrence-free (RFS), melanoma-specific (MSS) and overall survival (OS) rates after adjuvant RT in a cohort of these latter patients in an era before effective systemic immunotherapy became available.