Suresh Kumar Mukherji MD, Presenter: Nothing to Disclose

Alicia Toledano, Abstract Co-Author: Nothing to Disclose

Clifford Beldon MD, Abstract Co-Author: Nothing to Disclose

Ilona Maria Schmalfuss MD, Abstract Co-Author: Nothing to Disclose

Jay Cooper MD, Abstract Co-Author: Nothing to Disclose

JoRean Sicks MS, Abstract Co-Author: Nothing to Disclose

Robert Jess Amdur MD, Abstract Co-Author: Nothing to Disclose

Scott Sailor MD, Abstract Co-Author: Nothing to Disclose

Laurie Ann Loevner MD, Abstract Co-Author: Nothing to Disclose

Phil Kousouboris MD, Abstract Co-Author: Nothing to Disclose

Kian Ang MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

Prior studies have determined that gross tumor volume (GTV) calculated from pre-treatment computer tomography (CT) can predict local control in squamous cell carcinoma arising in different subsites in the head and neck in patients treated with non-surgical organ preservation therapy. The majority of these studies have been single institution retrospective investigations. As a result, there has been concern that GTV measurements may not be reproducible by different readers at different institutions. The purpose of our study was to measure the interobserver reliability for GTV measurements for squamous cell carcinoma of the supraglottic larynx (SGSCCA) performed by different readers at different institutions.

Eight experienced readers (4 neuroradiologists, 4 radiation oncologists) from different institutions independently measured the pre-treatment GTV of 20 patients with SGSCCA. The CT scans were obtained from patients entered into the definitive radiation therapy arm of Radiation Therapy Oncology Group protocol 91-11, who had supraglottic carcinoma and underwent pre-treatment CT of the neck. Statistical analysis focused on interobserver reliability as measured by the intraclass correlation coefficient.

The intraclass correlation coefficient was 0.81 (95% lower confidence bound: 0.71). This value is interpreted as “excellent”

GTV measurements are reliable and reproducible when performed by neuroradiologists and radiation oncologists experienced in the interpretation of CT of the extracranial head and neck in patients with SGSCCA. This implies that the correlation between GTV and local control should be reproducible across institutions.

Mukherji, S, Toledano, A, Beldon, C, Schmalfuss, I, Cooper, J, Sicks, J, Amdur, R, Sailor, S, Loevner, L, Kousouboris, P, Ang, K, et al, , Interobserver Reliability of CT-Derived Primary Tumor Volume Measurement In Patients With Supraglottic Carcinoma.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4407320.html