Quantitative dynamic contrast-enhanced magnetic resonance imaging for early assessment of treatment response in pancreatic ductal adenocarcinoma.

OBJECTIVES: To prospectively evaluate whether quantitative DCE-MRI can predict early chemotherapy response in pancreatic ductal adenocarcinoma (PDAC), and to assess the added value of a point-of-care portable perfusion phantom (P4) for correcting scanner-dependent errors. MATERIALS AND METHODS: Fifty-four patients with biopsy-confirmed PDAC were prospectively enrolled at two institutions; 42 completed MRI scans at baseline (1 ± 1 weeks before chemotherapy) and 7 ± 2 weeks after treatment initiation. P4s were imaged concurrently to correct for scanner-dependent measurement errors. Eleven pharmacokinetic (PK) parameters were derived using Tofts, extended Tofts, and shutter speed models. Treatment response at 17 ± 4 weeks was assessed using the modified RECIST, with responders defined as patients with > 10% tumor size reduction. Early changes in PK parameters were analyzed using receiver operating characteristic curves to assess predictive accuracy, and differences between responders and non-responders were assessed using one-way ANOVA. RESULTS: Among 42 patients (median age 67 years; 27 males), 20 were responders and 22 non-responders. Early changes in Ktrans (ΔKtrans) significantly distinguished responders from non-responders across all PK models, achieving ~80% predictive accuracy before P4 correction. After P4-based correction, ΔKtrans accuracy improved to 98% with the extended Tofts model. In contrast, standard RECIST-based CT assessment at 8 ± 2 weeks identified response in only 17% of patients. CONCLUSION: Quantitative DCE-MRI enables early, highly accurate prediction of chemotherapy response in PDAC, and P4-based error correction further enhances reliability. This approach offers a prospectively validated imaging biomarker that can support timely, personalized treatment decisions for patients with PDAC. KEY POINTS: QuestionCan quantitative dynamic contrast-enhanced MRI accurately identify early chemotherapy response in PDAC before conventional morphologic changes become apparent on CT? FindingsP4-corrected quantitative DCE-MRI predicted 17-week tumor response with up to 98% accuracy after only 7 weeks of chemotherapy treatment. Clinical relevanceP4-corrected quantitative DCE-MRI may enable earlier identification of ineffective chemotherapy in pancreatic cancer, supporting timely treatment modification, reducing unnecessary toxicity, and facilitating more personalized patient management.