ICHNO-ECHNO 2022 - Abstract Book

S50

ICHNO-ECHNO 2022

neck metastasis. Follow-up consisted of clinical examination, biochemical and radiological assessments (total body CT or PET-CT) in accordance with standard clinical care. Response and overall survival were analysed. Results Twenty-nine evaluable patients were diagnosed with oligometastatic SCCHN. Patients were mainly men (82.7%), with a median age of 70 years (range 49 - 85), with a median BMI of 21.3 and mainly smokers (82.7%), The oligometastatic sites included the lungs in 15 patients (51.7%), mediastinal lymph nodes in 8 patients (27.7%), both lung and mediastinal lymph nodes in 3 patients (10.4%), liver in 1 patient (3.4%), bone in 1 patient (3.4%), and oesophagus in 1 patient (3.4%). Height patients (27.7%) did not receive systemic treatment and they were referred to specialized palliative care, 9 (31%) received chemotherapy and 12 (41.3%) received chemo-immunotherapy or immunotherapy. Among the 21 treated patients, 10 (34.5%) received local treatment. One patient with a lung metastasis underwent surgical resection, and the remaining 9 patients received stereotactic radiotherapy. Height of them (80%) obtained a response (5 partial remission and 3 complete remission). The median overall survival was 9 months in all patients, 10.5 months in patients who received immunotherapy, and 18 months in patients who received both local treatment and immunotherapy. Conclusion In this cohort of patients with limited oligometastatic head and neck cancer, local treatment added to immunotherapy appears to be associated with improved survival. However, this retrospective analysis does not answer whether the survival benefit is due to selection of patients versus local interventions. 1 University Hospital Ostrava Poruba, Oncology clinic, Ostrava, Czech Republic; 2 University Hospital Ostrava, Oncology clinic, Ostrava, Czech Republic Purpose or Objective Nasopharyngeal carcinoma is known to be highly chemo and radiosensitive and radiotherapy with chemotherapy remains the standard of treatment. Local control has been shown to correlate with the total delivered radiation dose up to 80Gy. However, the dose escalation was associated with additional toxicity. In advanced inoperable oral cavity carcinomas the conventional radiotherapy and chemotherapy regimens have reported poor outcomes. A higher biologically effective dose to the primary tumor is required to improve outcomes. The dose escalation with standard IMRT techniques may be limited by the volume of irradiated organs at risk. Historically brachytherapy in combination with EBRT was an effective technique for dose escalation, but in technically or medically unfeasible cases (large tumor, contraindication to invasive procedures) an image-guided stereotactic radiotherapy technique is a new alternative promising treatment option. We evaluated the efficacy and toxicity of stereotactic hypofractionated boost in combination with EBRT in the treatment of advanced stage of nasopharyngeal and oral cavity cancer. Materials and Methods Between March 2011 and October 2018, twenty-eight patients with nasopharyngeal cancer stage III-IVA and thirty-seven patients with squamous cell carcinoma (p16 negative) of the oral cavity stage IVA-IVB, ineligible for surgical treatment were indicated for radiochemotherapy or hyperfractionated accelerated radiotherapy (HART). Concurrent chemotherapy cisplatin 40mg/m2 weekly was used. The radiotherapy protocol combined EBRT and stereotactic boost to the primary tumor. The dose delivered from EBRT was 70-72.5Gy in 35/50 fractions. The stereotactic boost followed EBRT course with 5-10Gy in 1-2 fractions. For the variables (tumor volume, stage , grade) a multivariate analysis was performed to find the relationship between overall survival, local progression and metastasis. Toxicity was evaluated according to CTCAE scale version 4. Results Complete remission was reached in 93% (26 patients) with nasopharyngeal cancer and 62% (23 patients) with oral cavity cancer. None of the patients required reirradiation. The 5y-OS was 75% in nasopharyngeal cancer and 27% in patients with oral cavity cancer. Statistical analysis revealed that larger tumors had worse overall survival and a greater chance of metastasis. Log-Rank GTV >44ccm (HR=1.96; [95% CI(0.87; 4.38)]; p=0.11). The maximum acute toxicity was grade 3 mucositis and dysphagia, manifested in 14 (22%) patients with oral cavity cancer and 4 (14%) patients with nasopharyngeal cancer. Late radiation toxicity manifested as osteonecrosis in 3(8%) and dysphagia 11(30%) in patients with oral cavity cancer. And hearing impairment in 3(11%), difficulty chewing and dysphagia in 6(21%) patients with nasopharyngeal cancer. PO-0087 Stereotactic boost in treatment of advanced nasopharyngeal and oral cavity cancer – long-term data T. Blazek 1,1 , Z. Zdeblova-Cermakova 2 , L. Knybel 2 , K. Resova 2 , J. Jackaninova 2 , J. Cvek 2