ICHNO-ECHNO 2022 - Abstract Book

S36

ICHNO-ECHNO 2022

Purpose or Objective Head and neck squamous cell carcinoma (HNSCC) often presents with synchronous nodules of the lung (SNL), as either benign nodules, pulmonary malignancies or metastases of HNSCC. Our aim was to convey an understanding about what is suggested as the proposed and best work-up for such cases, to provide an overview on publications until the year 2020 and to fill the literature gap regarding synchronous primary malignancies of the lung (SPML) and HNSCC. Materials and Methods In line with the PRISMA guidelines, two authors conducted a systematic search in the PubMed database independently. Searches combined disease and incidence specific terms, using the Boolean operator functions in all searches. All articles were evaluated according to the Oxford Centre of Evidence Based Medicine (OCEBM) levels. Results From a total of 2591 abstracts, 70 abstracts were narrowed down to 48 full-text articles. 27 papers, published until 2020, could be included for data extraction. Most of the publications were on OCEBM level 2a and 2b. Mean and median sample sizes were 674 and 399 cases, respectively. SNL ranged from 2-49%, whereas SPML ranged from 0.4-6.9% (median: 2.7%) of all patients. Most patients report smoking history (53-100%). Chest X-ray, CT and PET/CT yield mean sensitivity of 55%, 93%, 96%, mean specificity of 97%, 97%, 96%, positive predictive value of 67%, 78%, 80% and negative predictive value of 78%, 98% and 96%, respectively. The mean and median survival times after curative treatment of SPML were 22 and 19 months (range: 12-45), respectively. Conclusion 2.7% of patients with HNSCC have SPML. Based on these results, the use of 18 FDG-PET/CT at the time of diagnosis and swift aggressive concomitant or sequential curative treatment of the SPML to the HNSCC is recommended. 1 Nottingham University Hospitals NHS Trust, Clinical Oncology, Nottingham, United Kingdom; 2 Nottingham University Hospitals NHS Trust, Medical Physics, Nottingham, United Kingdom Purpose or Objective Hypoxia in head and neck squamous cell carcinomas (HNSCC) confers a worse prognosis and increased resistance to radiotherapy. Studies employing hypoxia modification have shown mixed results, partly due to limited stratification by tumour oxygenation. Current methods of determining hypoxia are limited by their invasive nature, limited capability for re-assessment, spatial resolution and availability of PET tracer. A novel imaging method called Oxygen Enhanced MRI (OE-MRI), where shortening of T 1 relaxation is proportional to molecular oxygen concentration has shown promise in pre-clinical models. We present initial results investigating the feasibility of OE-MRI in imaging hypoxia in HNSCC. Materials and Methods 5 volunteers and 3 patients underwent OE-MRI on 1.5T scanner (Sola, Siemens) using posterior head and anterior flex coils. After an initial scanning period on room air, oxygen was delivered via a non-rebreathe mask and serial T 1 mapping performed using 3D spoiled GE (voxel: 1.6x1.6x2.5, TR/TE=4.2/1.47ms, FA=2/18°) and DIXON (TR/TE=7.2/4.77ms, FA=2/12°). Data was processed using custom written software (MATLAB, Mathworks) and T 1 change ( Δ T 1 ) maps produced, with zero / positive Δ T 1 implying hypoxia or lack of perfusion. Results All participants tolerated the OE-MRI scan well. Motion during the serial acquisition was noted (figure 1) and consists of a non-rigid element due to swallowing and breathing. Compensation for this is crucial for accurate hypoxia assessment. PO-0068 Initial experience of oxygen enhanced MRI in determining regions of hypoxia in head and neck cancer A. McCabe 1 , R. Panek 2