Involved-Field Radiation Therapy for Patients With Unresectable Pancreatic Adenocarcinomas: Failure Pattern Analysis.

Area of Science:

• Oncology
• Radiation Oncology
• Gastrointestinal Oncology

Background:

• Unresectable pancreatic tumors often require chemotherapy, with radiotherapy considered for local control and symptom relief.
• The optimal volume for radiotherapy treatment fields in pancreatic cancer remains debated.
• Involved-field radiation therapy (IFRT) may reduce side effects but potentially increase regional failures.

Purpose of the Study:

• To analyze the failure patterns in patients with unresectable pancreatic adenocarcinomas treated with chemotherapy and IFRT.

Main Methods:

• Retrospective analysis of 30 patients with unresectable pancreatic adenocarcinoma treated from March 2016 to June 2020.
• Patients received initial systemic chemotherapy (gemcitabine or folfirinox/folfox) followed by IFRT (50-54 Gy).
• Failure patterns were categorized as local failure (LF), distant failure (DF), or elective nodal failure (ENF).

Main Results:

• The median survival was 17.2 months.
• Failure patterns included LF (23.3%), DF (56.7%), and combined LF/DF (16.7%).
• Only one patient experienced both LF and ENF; no severe radiotherapy side effects were reported.

Conclusions:

• IFRT in unresectable pancreatic cancer is associated with a low rate of elective nodal failure and minimal toxicity.
• The predominant failure pattern observed was distant metastasis.
• IFRT is a viable and safe treatment option for patients with locally advanced pancreatic tumors or poor performance status.