Abstract
Objective (Background):
Pancreatic cancer continues to have a poor prognosis, with a 5-year survival rate of approximately 8%. Because tumor formation progresses slowly and early symptoms are minimal, many patients are diagnosed at an advanced stage. In contrast, favorable outcomes have been reported in micro-pancreatic cancers measuring ≤1 cm and in carcinoma in situ (PanIN, Stage 0). These findings highlight the need for screening strategies capable of detecting abnormalities during the pre-mass-forming phase. MRI/MRCP is useful for identifying subtle early changes such as main pancreatic duct stenosis, irregularity of branch ducts, and diffusion restriction on DWI/ADC maps.
Methods:
Although conventional abdominal ultrasonography provides poor visualization of the pancreatic tail, the water-ingestion method stabilizes the acoustic window and is expected to improve detection of cystic lesions. Our institution implemented a pancreatic cancer screening program combining water-ingestion ultrasonography with MRI/MRCP. A total of 36 individuals underwent this combined protocol. Screening results and subsequent diagnostic outcomes were evaluated.
Results:
Cystic pancreatic lesions were identified in 5-6 of the 36 participants. In addition, a multimodal diagnostic approach including tumor markers enabled detection of a 5-mm micro-pancreatic cancer that showed no ductal abnormality on MRCP but was visualized only as focal diffusion restriction on DWI/ADC imaging. The lesion was successfully resected by robot-assisted distal pancreatectomy, achieving curative resection.
Conclusions:
A diagnostic system centered on MRI, particularly DWI/ADC evaluation, and a screening protocol incorporating water-ingestion ultrasonography are highly effective for detecting early pancreatic cancer, including lesions in the pre-mass-forming stage. The ability to identify a microcarcinoma as small as 5 mm demonstrates the clinical value of this multimodal strategy, which may contribute to improving outcomes by enabling earlier diagnosis and treatment.
