ICHNO-ECHNO 2022 - Abstract Book

S35

ICHNO-ECHNO 2022

PO-0066 [68Ga]Ga-tilmanocept PET/CT lymphoscintigraphy for sentinel lymph node detection in oral cancer

D. Donders 1 , R. Mahieu 1 , G. Krijger 2 , T. Ververs 2 , R. de Roos 2 , J. Bemelmans 2 , B. de Keizer 3 , R. de Bree 1

1 University Medical Center Utrecht, Head and Neck Surgical Oncology, Utrecht, The Netherlands; 2 University Medical Center Utrecht, Pharmacy, Utrecht, The Netherlands; 3 University Medical Center Utrecht, Radiology and Nuclear Medicine, Utrecht, The Netherlands Purpose or Objective To compare sentinel lymph node (SLN) identification using [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy to [ 99m Tc]Tc- tilmanocept lymphoscintigraphy (including SPECT/CT) in early-stage oral cancer. Furthermore, to assess whether reliable intraoperative SLN localization can be performed with a conventional portable gamma-probe using [ 99m Tc]Tc-tilmanocept without interference of 68 Ga in these patients. Materials and Methods This prospective within-patient comparison pilot study evaluated SLN identification by [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy compared to conventional lymphoscintigraphy using [ 99m Tc]Tc-tilmanocept (74 MBq) in 14 early-stage oral cancer patients scheduled for SLN biopsy. After conventional [ 99m Tc]Tc-tilmanocept lymphoscintigraphy, patients underwent peritumoral administration of [ 68 Ga]Ga-tilmanocept (9.12 MBq; ±0.66) followed by PET/CT acquisition initiated 16.2 (±2.2) minutes after injection. Intraoperative SLN localization was performed under conventional portable gamma- probe guidance; the location of harvested SLNs was correlated to both lymphoscintigraphic images in each patient. Results A total of 30 SLNs were identified by [ 99m Tc]Tc-tilmanocept lymphoscintigraphy, all except two were also identified by [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy. [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy identified 6 additional SLNs near the injection site, of which two harbored metastases. Lymphatic vessels transporting [ 68 Ga]Ga-tilmanocept were identified by PET/CT lymphoscintigraphy in 86% of patients, while draining lymphatic vessels were visualized by [ 99m Tc]Tc- tilmanocept lymphoscintigraphy in 14% of patients. Of the 40 SLNs identified by [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy, 36 (90%) were intraoperatively localized under conventional gamma-probe guidance. Conclusion [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy provided more accurate identification of SLNs and improved visualization of lymphatic vessels compared to [ 99m Tc]Tc-tilmanocept lymphoscintigraphy. When combined with peritumoral administration of [ 99m Tc]Tc-tilmanocept, SLNs detected by [ 68 Ga]Ga-tilmanocept PET/CT lymphoscintigraphy can be reliably localized during surgery under conventional gamma-probe guidance. Because of these good results, preparations are being made for a multicenter study.

PO-0067 Work-up of head and neck cancer with synchronous lung nodules: diagnostic and therapeutic challenge

R. Giger 1 , M. Müller 2 , J. Li 3 , O. Elicin 4

1 Inselspital, Bern University Hospital, ENT, Head and Neck Surgery, Bern, Switzerland; 2 Liechtenstein Free University, Liechtenstein Free University, Triesen, Liechtenstein; 3 NMC-Hospital Group Cooper Health Clinic Dubai, NMC-Hospital Group Cooper Health Clinic Dubai, Dubai, United Arab Emirates; 4 Inselspital, Bern University Hospital, Radiation Oncology, Bern, Switzerland