Particle therapy for pancreatic cancer

Achieving local control for patients with nonmetastatic pancreatic malignancy represents a substantial challenge. For patients with unresectable disease, data from the LAP-07 trial suggests that conventionally delivered X-ray based radiotherapy does not offer a survival improvement compared to treatment with chemotherapy alone. While the study methodology has been challenged, the published results from the ESPAC trial suggest that radiotherapy likewise does not improve survival for patients after extirpative surgery. The shortcomings of X-ray based therapy, to a significant degree, are due to the fact that the tumor targets are intimately surrounded by highly radiosensitive normal tissues resulting in both toxicity and limitation in the deliverable radiotherapy dose. Particle therapy may offer improvements in the therapeutic index as compared to X-ray based therapies. Such improvements may allow for treatment intensification while minimizing normal tissue complications. Herein we review dosimetric studies as well as encouraging preliminary clinical outcome data which suggest that particle therapy may represent a valuable addition to the armamentarium used to treat this malignancy.