With limited treatment options, pancreatic cancer is the fourth most common cause of cancer-related death among American men and women. In fact, the only potentially curative treatment available is margin-negative surgical resection.
However, not all pancreatic cancer tumors are resectable, and failure to pre-operatively determine if a tumor is unresectable can result in morbidity and mortality.
Kim
The key to making such a determination is abdominal imaging, with the National Comprehensive Cancer Network recommending thin section pancreas protocol CT for preoperative staging.
“A pre-operative pancreas protocol CT scan has long been the best-validated imaging modality for staging and resection planning – at least for now,” said Jesi Kim, MD, a radiology resident at NYU Langone Health in New York.
According to Dr. Kim, photon-counting CT, (PCCT) which is becoming increasingly commonplace in clinical practice, allows for improved spatial resolution without a dose penalty compared to conventional CT. It also has the advantage of a superior iodine contrast-to-noise ratio.
But do these advantages translate to a better assessment of pancreatic cancer resectability?
That’s what a new study conducted by the NYU Langone Department of Radiology intended to find out.
“Accurate and consistent resectability assessment across multiple readers is critical for presurgical planning,” said Dr. Kim, the study’s lead author. “As photon counting CT was recently introduced into clinical practice, it is important to compare it with conventional CT.”
Comparing Inter-Reader Agreement of PCCT And EID CT
The study, which Dr. Kim presented during a Tuesday session, compared the diagnostic performance and inter-reader agreement of resectability of pancreatic adenocarcinoma using a PCCT with that of a 128-slice conventional energy-integrating detector CT (EID CT).
During the study, patients with pancreatic adenocarcinoma underwent pancreas protocol CT with either PCCT (67 patients) or EID CT (66 patients). Thirty-eight of these patients had surgery immediately following the index scan.
Two abdominal radiologists assessed the degree of tumor involvement of the celiac artery, common hepatic artery, superior mesenteric artery (SMA), superior mesenteric vein (SMV) and main portal vein (MPV)—all of which serve as reliable CT indicators of unresectability.
The readers then classified tumor resectability as being either resectable, borderline resectable, locally advanced and unresectable, or unresectable metastatic.
PCCT Improved Diagnostic Accuracy
What researchers found was that the use of PCCT substantially increased inter-reader agreement.
“There was a substantial increase in inter-reader agreement for three of the major vessels we assessed—celiac artery, SMA and SMV—with the photon counting CT scans compared to the conventional EID CT scans,” said Dr. Kim.
Furthermore, the use of PCCT resulted in a substantial increase in reader agreement as to the presence of metastasis.
Researchers also found that PCCT improved diagnostic accuracy for MPV and SMA involvement and increased a radiologist’s diagnostic confidence. More so, all these improvements were achieved at lower patient radiation exposure.
“This study shows that PCCT’s improved spatial resolution and better iodine contrast to noise ratio does in fact translate into improved inter-reader agreement for certain vessel involvement and the detection of metastasis,” Dr. Kim concluded. “These advantages also improve the diagnostic accuracy of pancreatic adenocarcinoma resectability and decrease radiation exposure compared to conventional CT.”
Access the presentation, “Inter-reader Agreement and Diagnostic Performance of Pancreatic Adenocarcinoma Resectability Assessment with Photon Counting CT Compared with Conventional Energy Integrating Detector CT,” (T1-SSGI08-2) on demand at Meeting.RSNA.org .
