Yingbing Wang MD, Presenter: Nothing to Disclose

Brett Wilson Carter MD, Abstract Co-Author: Nothing to Disclose

Victorine Vining Muse MD, Abstract Co-Author: Biomedical Systems Consultant

Subba Rao Digumarthy MD, Abstract Co-Author: Nothing to Disclose

Jo-Anne O. Shepard MD, Abstract Co-Author: Nothing to Disclose

Amita Sharma MBBS, Abstract Co-Author: Nothing to Disclose

The purpose of our study is to characterize the pleural and extrapleural deposition of talc from pleurodesis in the thorax. 

Institutional Review Board approval was obtained for this retrospective study, and informed consent was waived. The electronic radiology and medical record database identified 36 patients who underwent PET/CT between January 2006 and December 2010 and had a history of talc pleurodesis. For each exam, the distribution pattern of talc in pleura and extrapleural lymph nodes, extent of pleural thickening and associated standardized uptake value (SUV) were recorded.

There were 17 male and 19 female patients with mean age of 64 ± 11 years. The indication for PET/CT was staging/re-staging of known malignancy in 33 patients (92%), suspected occult malignancy in 2 patients (5%) and sarcoidosis in 1 patient (2%). Mean interval between talc pleurodesis and PET/CT was 32 ± 37 months. High attenuation pleural thickening with associated FDG uptake was distributed in the dependent pleura in all patients and multifocal in 28 (77%) and circumferential in 8 (23%) patients. High attenuation extrapleural lymph nodes were noted in 13 patients (36%), and all of these sites had corresponding increased FDG uptake. Involved nodal groups included peridiaphragmatic (46%), paracardiac (38%), paratracheal (15%), internal mammary (15%), peri-IVC (15%), and ipsilateral hilar (8%). Four of the 13 patients (30%) had involvement of multiple lymph nodal groups. All of these findings persisted on longitudinal imaging following up.

Extrapleural talc deposition in intrathoracic lymph nodes is common and appears to preferentially involve the peridiaphragmatic and paracardiac lymph nodes, although involvement of paratracheal, internal mammary and ipsilateral hilar lymph nodes can also occur.

Our study adds to existing knowledge regarding potential pitfalls in the interpretation of FDG PET/CT scan in the post-pleurodesis thorax with findings that have never been previously described.

Wang, Y, Carter, B, Muse, V, Digumarthy, S, Shepard, J, Sharma, A, 18 FDG PET-CT after Talc Pleurodesis: Evaluation of Pleural and Extra Pleural Lymph Nodes.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11004943.html