Optimizing neoadjuvant radiotherapy for resectable and borderline resectable pancreatic cancer using protons

Abstract

Approximately 25% of patients diagnosed with pancreatic cancer present with non-metastatic resectable or borderline resectable disease. Unfortunately, the cure rate for these “curable” patients is only in the range of 20%. Local-regional failure rates may exceed 50% after margin-negative, node-negative pancreatectomy, but up to 80% of resections are associated with regional lymph node or margin positivity. While systemic drug therapy and chemotherapy may prevent or delay the appearance of distant metastases, it is unlikely to have a significant impact on local-regional disease control. Preoperative radiotherapy would represent a rational intervention to improve local-regional control. The barrier to preoperative radiotherapy is the concern that it could potentially complicate what is already a long and complicated operation. When the radiotherapy is delivered with X-rays (photons), the entire cylinder of the abdomen is irradiated; therefore, an operating surgeon may be reluctant to accept the associated risk of increased toxicity. When preoperative radiotherapy is delivered with protons, however, significant bowel and gastric tissue-sparing is achieved and clinical outcomes indicate that proton therapy does not increase the risk of operative complications nor extend the length of the procedure.

Development of a Nomogram to Predict Disease-Specific Survival for Patients After Resection of a Non-Metastatic Adenocarcinoma of the Pancreatic Body and Tail

“…A phase-II clinical trial revealed that neoadjuvant FOLFIRINOX followed by individualized chemoradiotherapy enabled a high prevalence of R0 resection and prolonged survival (27). Radiotherapy delivered with protons and stereotactic body radiation may be beneficial to treatment of pancreatic cancer (28,29). It is necessary to conduct further research on the role of radiotherapy in pancreatic cancer.…”

Radioactive 125I seed implantation for pancreatic cancer with unexpected liver metastasis: A preliminary experience with 26 patients

“…125 I seeds can continuously release a low dose of γ-ray when they are implanted into tumor tissue. It can damage the DNA of tumor cells and induce apoptosis of tumor cells, so as to kill the proliferative cancer cells[ 17 , 18 ]. The advantages of 125 I seeds in the treatment of pancreatic cancer are local adaptation and low dose continuous therapy[ 19 - 21 ].…”

Radioactive 125I seed implantation for locally advanced pancreatic cancer: A retrospective analysis of 50 cases

“…The DNA of tumor cells in the proliferative period is in the late stage of synthesis and mitosis and is extremely sensitive to gamma rays. A small number of gamma rays can destroy DNA, preventing tumor cell proliferation[ 20 , 21 ]. After implantation into tumor tissue, 125 I seeds can continuously release low-dose gamma rays to kill tumor cells, damage the DNA of tumor cells, inhibit tumor cell proliferation, and induce tumor cell apoptosis.…”