Abstract
It is the purpose of this study to evaluate how self‐expanding stents (SESs) affect esophageal cancer radiation planning target volumes (PTVs) and dose delivered to surrounding organs at risk (OARs). Ten patients were evaluated, for whom a SES was placed before radiation. A computed tomography (CT) scan obtained before stent placement was fused to the post‐stent CT simulation scan. Three methods were used to represent pre‐stent PTVs: 1) image fusion (IF), 2) volume approximation (VA), and 3) diameter approximation (DA). PTVs and OARs were contoured per RTOG 1010 protocol using Eclipse Treatment Planning software. Post‐stent dosimetry for each patient was compared to approximated pre‐stent dosimetry. For each of the three pre‐stent approximations (IF, VA, and DA), the mean lung and liver doses and the estimated percentages of lung volumes receiving 5 Gy, 10 Gy, 20 Gy, and 30 Gy, and heart volumes receiving 40 Gy were significantly lower (p‐values <0.02) than those estimated in the post‐stent treatment plans. The lung V5, lung V10, and heart V40 constraints were achieved more often using our pre‐stent approximations. Esophageal SES placement increases the dose delivered to the lungs, heart, and liver. This may have clinical importance, especially when the dose‐volume constraints are near the recommended thresholds, as was the case for lung V5, lung V10, and heart V40. While stents have established benefits for treating patients with significant dysphagia, physicians considering stent placement and radiation therapy must realize the effects stents can have on the dosimetry.PACS number: 87.55.dk
Highlights
Esophageal cancer is a highly lethal and increasingly incident malignancy
The aim of this study was to quantify the impact of esophageal self-expanding stent (SES) on the planning target volume (PTV) and the radiation dose delivered to organs at risk (OARs) in patients with esophageal cancer
The PTV was affected more modestly by SES placement, increasing only 13%, 8%, and 8% using Image fusion (IF), Volume approximation (VA), and Diameter approximation (DA) pre-stent approximations, respectively
Summary
It is estimated that 17,460 men and women were diagnosed and 15,070 people died from esophageal cancer in 2012.(1) Standard of care treatment for locoregionally advanced disease (i.e., ≥T3 or node positive) involves concurrent chemoradiotherapy, which is either done in the neoadjuvant setting[2] or as definitive therapy[3] to improve overall survival. This disease often causes malignant dysphagia, which may require intervention with a feeding tube or esophageal self-expanding stent (SES) if the obstruction prevents adequate nutrition. When a combination of SES use and radiotherapy is employed, the inclusion of a stent in the radiation field introduces important questions regarding tumor and OAR dosimetry, as well as patient safety
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
