case_images: PMC10865071_01
case_images: Pre- and post-therapy 18F-FDG PET/CT and treatment planning CT. a-c: pre-treatment 18F-FDG PET/CT: (a) maximum intensity projection (MIP); (b) axial fusion image of PET/CT with pulmonary window; (c) coronal fusion image of PET/CT with soft tissue window. d-e: radiation planning CT. f: post-treatment 18F-FDG PET/CT MIP image.. In the pre-treatment positron emission tomography (PET)/CT, there is a 57 mm tumor in the right upper lobe S1 adjacent to the mediastinum, showing an 18F-FDG uptake with a maximum standardized value of 27.1 (a-c). In the treatment planning CT, bold circles indicate isodose lines. Thin red, orange, yellow, and cyan circles indicate the gross tumor volume (GTV), clinical target volume (CTV), planning target volume (PTV), and spinal canal, respectively (d, e). In the post-treatment 18F-FDG PET/CT, a reduction in the lesion can be observed. The uptake near the vertebrae is non-specific, possibly due to degenerative changes.
case_images: cureus-0016-00000052283-i01.jpg
case_images: PMC10865071_01_cureus-0016-00000052283-i01.jpg
case_images: FIG1
case_images: A computed tomography (CT) and subsequent 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography/CT (18F-FDG PET/CT) revealed a 5.7 cm tumor in segment S1 of the right upper lobe of the lung, adjacent to the mediastinum without metastasis (Figure 1, a-c). During RT, the brachial plexus received a radiation dose of 47-48 Gy (Figure 1, d, e, bold orange circle). One month after completing the CRT, the patient's assessment with an 18F-FDG PET/CT scan revealed a decrease in both the size and metabolic activity of the lesion (Figure 1, f).
case_images: Comparison of postoperative brachial plexus evaluation and radiation planning CT images. (a) In three-dimensional (3D) MR neurography, signal enhancement in the right brachial plexus (a, yellow arrow) and discontinuous fluid retention within postoperative scar tissue (a, white arrow) are depicted; (b, c) On the coronal 2D short tau inversion recovery (STIR) images, high signal intensity consistent with the right brachial plexus (yellow arrows) and postoperative scar tissue (white arrows) is observed, with the subclavian artery (blue arrows) intervening; (d, e) On contrast-enhanced CT, the lesion (yellow arrow) and postoperative scar tissue (white arrow) are separated by the right subclavian artery (blue arrows), confirming discontinuity; (f) Compared to the pre-treatment radiation planning CT, the abnormal signal in the brachial plexus corresponds to the area receiving 95% of the prescribed dose of 50 Gy (yellow arrows).
case_images: cureus-0016-00000052283-i02.jpg
case_images: PMC10865071_01_cureus-0016-00000052283-i02.jpg
case_images: FIG2
case_images: Ten months after the completion of CRT, a cervical spine magnetic resonance imaging (MRI) was performed, revealing localized high signal intensity in the right brachial plexus on both three-dimensional (3D) MR neurography and 2D short tau inversion recovery images (Figure 2 a-c). The contrast-enhanced CT scan showed that the right subclavian artery was running between the area of abnormality seen in the MRI and the post-surgical scar tissue, confirming discontinuity (Figure 2 d, e). When compared to the irradiation field, this corresponded with the area receiving 95 % of the prescribed dose of 50 Gy (Figure 2 f, yellow arrows).