Andrew Tan Eh MBBS, FRCR, Presenter: Nothing to Disclose

Yung Hsiang Kao MBBS, MRCP, Abstract Co-Author: Nothing to Disclose

Wan Ying Xie, Abstract Co-Author: Nothing to Disclose

Su Ping Thang, Abstract Co-Author: Nothing to Disclose

External beam radiotherapy is used routinely in a wide variety of tumors, but radiation induced tissue necrosis or radionecrosis can confound post treatment evaluations for remnant viable tumor. Accurate assessment of treatment response and early detection of remnant or recurrent disease is important for salvage therapy. We present our initial experiences in utilizing Technetium99m-Sestamibi (Tc99m-Sestamibi) SPECT/CT in differentiating radiation necrosis from viable tumor.

Tc99m-Sestamibi SPECT/CT imaging was performed for 6 patients with indeterminate imaging findings on follow-up, suspicious for osteoradionecrosis, but for which local tumor recurrence could not be excluded. For the initial primary tumor, 4 patients had nasopharyngeal carcinomas, 1 patient had glioblastoma multiforme and 1 patient had colorectal carcinoma. All tumors were histologically proven, and all had local external beam radiotherapy as part of their therapy.

All imaging findings were correlated with histopathological reports or interval long term imaging follow-up. There were 5 true negative cases and 1 true positive case. No false negatives or positives were encountered. Overall accuracy for our small series was 100%.

Tc99m-Sestamibi SPECT/CT has potential clinical utility in differentiating radionecrosis from viable tumor in a variety of cancers.

This is a novel technique that has significant relevance in addressing a current clinical problem.

Tan Eh, A, Kao, Y, Xie, W, Thang, S, Utilizing Technetium99m-Sestamibi SPECT/CT in Differentiating Radionecrosis from Viable Tumor.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11010523.html