Proton beam radiotherapy for pancreas cancer

Abstract

Pancreatic carcinoma is a challenging malignancy to manage with a very poor prognosis. Despite continued difficulties in its management, there have been incremental improvements in outcomes over the past several decades. Achieving the best oncologic outcomes requires a multimodality approach including surgery, chemotherapy, and radiotherapy. Proton radiotherapy enables the delivery of high-dose radiotherapy to the tumor or resection bed while sparing nearby critical organs. Due to their unique physical properties, protons can deliver radiotherapy dose distributions that are not achievable with photons (X-rays) even with advanced photon delivery techniques (e.g., intensity-modulated radiotherapy). Improved dose distributions can lead to reduced treatment toxicity and enable treatment intensification. As better chemotherapy regimens lead to better systemic disease control, it will become increasingly important that local-regional control is achieved. This will in part be accomplished by combining better radiotherapy with more active chemotherapies. Proton radiotherapy provides an excellent means for achieving this.

Keywords: Radiotherapy; outcomes; pancreas cancer; pancreatic cancer; particle therapy; proton therapy.

Figure 1

Dosimetry comparison VMAT, PS protons, and PBS protons. Comparison planning between VMAT (X-rays), passively scattered proton therapy (PS), and pencil beam scanning proton therapy (PBS). The light shaded green includes gross disease and regional elective lymph nodes and received 40.05 GyRBE (2.25 Gy/fx). The dark shaded green contour is the high dose planning target volume which is prescribed to receive 63 GyRBE (2.25 Gy/fx).