ICHNO-ECHNO 2022 - Abstract Book

S48

ICHNO-ECHNO 2022

Bufavirus (BuV), and Tusavirus (TuV) are under active investigation. CuV has been detected in tumors such as skin biopsies of CTCL, melanoma and in a formalin-fixed paraffin-embedded (FFPE) samples of salivary gland pleomorphic adenoma. Materials and Methods We took punch biopsies from 26 sinonasal lymphomas for investigation of 20 DNA viruses ( Herpesviridae, Parvoviridae, Polyomaviridae ) with qPCR. For selected tumors positive for virus DNA we performed RT-PCR and RNAscope to detect and localize virus RNA. We performed ELISA to search for IgG of protoparvoviruses in 11/26 patients with a plasma sample available. Results We detected virus DNA in 17/26 (65%) tumors: 1 positive for CuV, 8 for Human herpesvirus 6B or/and -7, 9 for EBV, 2 for cytomegalovirus, 1 for Merkel cell polyomavirus and 5 for parvovirus B19. Multiple virus DNA findings were made in 8/26 (31 %) tumors. We found positive signals in RNAscope for CuV- and EBV-positive tumors. ELISA detected a notable seroprevalence of 27% for CuV and 64% for BuV2 indicating a persistent viremia. Conclusion Multiple viruses are present in sinonasal lymphomas and often concomitantly. This study is the first to demonstrate presence of CuV DNA and RNA in sinonasal lymphoma.

PO-0083 Salvage surgery in residual or recurrent oropharyngeal cancer: The Amsterdam experience.

S. Eerenstein 1

1 Amsterdam UMC VUmedical center, ENT Head&Neck surgery, Amsterdam, The Netherlands

Purpose or Objective Residual and recurrent disease after (chemo)radiotherapy is associated with poor prognosis and surgical difficulties. The aim of our study is to assess the efficacy of salvage surgery in case of residual or recurrent disease in our (chemo)radiotherapy patient population from the switch to non-surgical treatment in 2000. Materials and Methods We reviewed the data of patients between 2000 and 2020. All patients who underwent salvage surgery for loco-regional residual or recurrent oropharyngeal cancer were included. Short and long-term complications were recorded. Kaplan-Meier analysis was used to determine overall survival and recurrence-free survival. Univariate analysis was performed using Cox proportional hazard regression. Results Forty-three patients underwent salvage surgery: fifteen with local tumor underwent local resection and neck dissection, 28 with regional tumor underwent neck dissection. Post-operative complications occurred in 17 patients (39.5%): fistula formation in 4 patients 26.6% and flap-failure in 2 patients (13.3%). Five-year overall survival for all patients was 39.6% and patient age during surgery was significant (p= 0.015). No significant difference was seen in survival between the loco-regional and regional tumor group (p=0.57). Previous treatment with chemoradiotherapy (21 patients) or radiotherapy only (22 patients) did not influence outcome (p=0.58). Seventeen patients (39.5%) needed long-term gastrostomy tube feeding postoperative and three patients (6.7%) remained tracheotomy dependent after salvage surgery. Clear margin resection (R0) was achieved in 33 patients (76.7%) and associated with longer overall survival (p=0.004). Clear margin resection was achieved in 83.3% of HPV positive tumors and 74.2% of HPV negative tumors (p=0.68). No association in 5-year overall survival was seen with HPV status, there was a difference (49.9% vs. 34.9%) between HPV positive and HPV negative, but this was not significant in this relatively small sample size.

Conclusion

Salvage surgery for oropharyngeal cancer after (chemo)radiotherapy may yield favorable results for patients, but is associated with high morbidity.

Poster: Innovative treatments

PO-0084 SIB-IMRT of the head and neck cancer with a neck prophylactic dose of 50 Gy or less

S. Nakamura 1 , M. Yui 1 , A. Yoshida 1 , K. Yoshida 1

1 Kansai Medical University, Radiation Oncology, Hirakata/Osaka, Japan

Purpose or Objective A decrease in the prophylactic irradiation dose in the curative irradiation of head and neck cancer is expected to lead to a reduction in late adverse events. We will investigate the treatment plan dose to normal tissues with a prophylactic irradiation dose of 48-50 Gy/33 doses (1.45-1.52 Gy/dose) in our SIB-IMRT.