Fiducial Marker Placement for Gated Radiotherapy Using Real-Time Tumor-Tracking in Pancreatic Cancer: A Comparative Analysis of Transarterial and Percutaneous Approaches.

[PURPOSE] To assess and compare the feasibility and safety of transarterial and percutaneous fiducial marker placements for gated radiotherapy using real-time tumor-tracking (RTRT) in patients with pancreatic cancer.

[MATERIALS AND METHODS] This retrospective cohort study included 61 patients with inoperable pancreatic cancer who underwent transarterial (n = 34) or percutaneous (n = 27) fiducial marker placement between 2015 and 2023. Technical and clinical success, adverse events (AEs), procedure time, number of markers, tumor-to-marker distance, migration, per-marker availability for RTRT, and reasons for marker unavailability were assessed.

[RESULTS] Both approaches achieved high technical and clinical success rates (transarterial approach, 91.4% and 97.1%; percutaneous approach, 96.3% and 96.3%; P = .626 and P = 1.000) without moderate or severe AEs. Mild AEs occurred in 2.9% and 7.4% of patients in the transarterial and percutaneous groups (P = .575). The median procedure time was shorter in the percutaneous group (35 vs 50 minutes, P = .006). The percutaneous group used more markers (3 vs 1 [median], P < .001). The median tumor-to-marker distance was comparable between groups (transarterial approach, 21 mm; percutaneous approach, 26 mm; P = .317). Migration occurred in only 1 percutaneous case (1.4%). On a per-marker basis, the transarterial group had higher marker availability for RTRT (97.1%) than the percutaneous group (70.8%, P = .001). Marker unavailability was due to untraceable shape (transarterial approach, 1; percutaneous approach, 12), lack of synchronization with tumor motion (percutaneous approach, 6), or others (percutaneous approach, 3).

[CONCLUSIONS] Transarterial and percutaneous fiducial marker placements are safe and feasible for administering RTRT in patients with pancreatic cancer.