Laura E. Kollar MD, Presenter: Nothing to Disclose

Edward Y. Kim MD, Abstract Co-Author: Nothing to Disclose

Few studies have been reported evaluating the rate of incidental findings on radiation treatment planning CT scans. We set out to review our own institutional experience with diagnostic radiology review of treatment planning CT scans and the resulting impact patient care.

At our institution, all radiation planning CTs are reviewed by a diagnostic radiologist. Reports from all radiation treatment planning CT scans over one year from a single treatment center were reviewed. Pertinent findings were considered those that were new or previously unreported and could potentially change or delay treatment decisions. These included findings reported involving the bone, lung, liver, adrenal glands, or lymph nodes. Other non-emergent, non-cancer related findings were not included in this study.  

347 CT scans for 326 patients were performed between January 1, 2013 and December 31, 2013. 145 were for primary breast malignancies, 19 of which were DCIS. The remainder of the scans included 35 prostate, 23 lymphoma, 16 multiple myeloma, 10 pancreatic, 10 endometrial, 7 cervical, 5 rectal, 50 metastases, and 27 other. 66 new findings were detected on a total of 56 scans (16.1%). These included 21 lung nodules, 14 bone lesions, 15 liver lesions, 5 adrenal nodules, and 11 enlarged or suspicious lymph nodes. 12 of these scans (21.4%) led to additional imaging. 4 patients experienced delay of radiotherapy due to further work up. 2 patients ultimately did not receive definitive treatment due to confirmation of metastatic disease. Of note, one patient found to have an indeterminate sclerotic bone lesion on treatment planning scan was confirmed to have bony metastatic disease 8 months later. Of the positive scans, 39 were for primary breast malignancies (69.5%).  

New or previously unreported findings are not uncommon in radiation treatment planning scans, with 16.1% of scans showing unexpected, potentially cancer-related findings. 8.3% of all scans, and 21.4% of positive scans, led to additional imaging.  

New findings as reported on diagnostic radiology review of radiation planning scans can have important clinical implications and may potentially change treatment recommendations for patients undergoing radiotherapy.  In our study, we found the rate of potentially cancer-related findings to be not uncommon, with such findings often leading to additional imaging to determine disease status.

Kollar, L, Kim, E, Incidental Findings on Radiation Treatment Planning CT Scans.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14016315.html