Understanding the PET/CT Scan Report

"left para-aortic lymph node at the level of L4" is simply referring to the location of the lymph node in question. L4 (from google) is apparently located in the lower region on the left side of the abdominal aorta. Your scan showed a "mild to moderate uptake" {of the PSMA tracer that was injected into you prior to your scan} in this lymph node. This tracer binds to PSMA protein (normally found in high amounts in prostate cancer cells) which helps "light up" prostate cancer in the scan. But it can sometimes bind to other tissue creating a false positive. From the sound of it, the individual(s) who reviewed the scan felt that based on the appearance in the scan, this small uptake of the tracer in this lymph node does not conclusively indicate that the node is cancerous. It's "indeterminate" as stated. Although PSMA PET scans are generally very accurate, false positives sometimes do occur. In the case of this particular lymph node, they are stating that they aren't sure. The good news is they also stated no other lymph nodes had any PSMA tracer uptake (meaning no cancer found). So you just have one lymph node that may be cancerous.