Other diagnostic studies for evaluating the spread of pancoast tumor include bone scintigraphy, PET scan, and molecular tests.
Other Diagnostic Studies
Bone Scintigraphy
A bone scan may demonstrate bone metastases.
PET scan
FDG(18 F fluoro deoxyglucose) PET scans along with contrast enhanced CT may be helpful in the diagnosis of extent of lung cancer. Findings on FDGPET/CT suggestive of lung cancer include:[1]
Role of FDG PET/CT in primary tumor delineation. Irregular soft tissue opacity seen on coronal CT scan (arrow, A) with no obvious demarcation between the tumor and surrounding consolidation. PET/CT shows the FDG-avid tumor (arrow, B) separate from the non–FDG-avid consolidation (arrowhead, B),via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F6/>[1]
FDG PET in nodal disease. Maximum intensity projection (MIP) image shows an FDG-avid primary lung tumor on the left side (arrow, A) and a focus of FDG uptake in the mediastinum (arrowhead, A). CT scan shows enhancing, spiculated primary tumor (arrow, B) and a small right paratracheal node (arrowhead, B) which is negative by size criteria. Fused PET/CT image shows FDG concentration in the primary (arrow, C) as well as the node (arrowhead, C), suggesting metastatic involvement. Mediastinoscopy and biospy revealed metastatic node-N3 disease,via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F8/9/>[1]
FDG PET in nodal disease false-positive study. Maximum intensity projection (MIP) image shows an FDG-avid primary lung tumor on the right side (arrow, A) and multiple foci of FDG uptake in the mediastinum (arrowhead, A). CT scan shows enhancing, primary tumor (arrow, B). Fused PET/CT image shows FDG concentration in the mediastinal nodes, suggesting metastatic involvement. Mediastinoscopy and biospy revealed tuberculosis,via <https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F9/>[1]
Pleural effusion and role of FDG PET/CT. Enhancing lung masses seen on CT scans in two different patients (arrows in A and C) with minimal pleural effusions (arrowheads in A and C). Corresponding PET/CT scans show intense FDG-avid metastatic pleural deposits (arrowheads in B and D) as the cause of effusions. Note that the pleural deposits are barely perceptible on CT, via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F14/>[4]
Incremental value of FDG PET/CT in baseline staging. MIP image of FDG PET scan shows intense tracer concentration in the right hemithorax (arrow, A) corresponding to a right lung mass (arrow, B). Also seen are two FDG-avid foci in the abdomen (arrowheads, A) which correspond to peritoneal metastatic deposits (arrowhead, C). Note that the peritoneal deposit is almost indistinguishable from adjacent bowel (arrowhead, D). Due to PET/CT findings, the intent of treatment changes from curative surgery of a resectable mass to palliative chemotherapy, via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F15/>This is an open-access article distributed under the terms of the Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.[4]
Adrenal adenoma versus metastasis. Enhancing solid adrenal nodule on CT scan in a case of lung cancer (arrow, A) suggestive of metastatic deposit. Unenhanced CT scan shows fatty attenuation within the nodule with an HU value of 0 suggesting the possibility of an adenoma (arrow, B). FDG PET/CT shows no tracer concentration in the nodule, confirming the diagnosis of adenoma. Enhancing solid adrenal nodule on CT scan in another patient of lung cancer (arrow, D), which is indeterminate in nature. FDG PET/CT shows abnormal focal tracer concentration in the nodule (arrow, E) highly suggestive of a metastatic deposit via<https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4419420/figure/F11/>[4]
Molecular Test
Molecular tests include epidermal growth factor receptor (EGFR) mutation and anaplastic lymphoma kinase (ALK) mutation. Specific targeted agents may be administered to patients if these mutations are present.
References
↑ 1.01.11.21.3Purandare, NilenduC; Rangarajan, Venkatesh (2015). "Imaging of lung cancer: Implications on staging and management". Indian Journal of Radiology and Imaging. 25 (2): 109. doi:10.4103/0971-3026.155831. ISSN0971-3026.
↑van Baardwijk, Angela; Baumert, Brigitta G.; Bosmans, Geert; van Kroonenburgh, Marinus; Stroobants, Sigrid; Gregoire, Vincent; Lambin, Philippe; De Ruysscher, Dirk (2006). "The current status of FDG–PET in tumour volume definition in radiotherapy treatment planning". Cancer Treatment Reviews. 32 (4): 245–260. doi:10.1016/j.ctrv.2006.02.002. ISSN0305-7372.
↑ 4.04.14.2Purandare, NilenduC; Rangarajan, Venkatesh (2015). "Imaging of lung cancer: Implications on staging and management". Indian Journal of Radiology and Imaging. 25 (2): 109. doi:10.4103/0971-3026.155831. ISSN0971-3026.
