Abstract
BackgroundAdaptive magnetic resonance imaging‐guided radiation therapy (MRgRT) can escalate dose to tumors while minimizing dose to normal tissue. We evaluated outcomes of inoperable pancreatic cancer patients treated using MRgRT with and without dose escalation.MethodsWe reviewed 44 patients with inoperable pancreatic cancer treated with MRgRT. Treatments included conventional fractionation, hypofractionation, and stereotactic body radiation therapy. Patients were stratified into high‐dose (biologically effective dose [BED10] >70) and standard‐dose groups (BED10 ≤70). Overall survival (OS), freedom from local failure (FFLF) and freedom from distant failure (FFDF) were evaluated using Kaplan‐Meier method. Cox regression was performed to identify predictors of OS. Acute gastrointestinal (GI) toxicity was assessed for 6 weeks after completion of RT.ResultsMedian follow‐up was 17 months. High‐dose patients (n = 24, 55%) had statistically significant improvement in 2‐year OS (49% vs 30%, P = 0.03) and trended towards significance for 2‐year FFLF (77% vs 57%, P = 0.15) compared to standard‐dose patients (n = 20, 45%). FFDF at 18 months in high‐dose vs standard‐dose groups was 24% vs 48%, respectively (P = 0.92). High‐dose radiation (HR: 0.44; 95% confidence interval [CI]: 0.21‐0.94; P = 0.03) and duration of induction chemotherapy (HR: 0.84; 95% CI: 0.72‐0.98; P = 0.03) were significantly correlated with OS on univariate analysis but neither factor was independently predictive on multivariate analysis. Grade 3+ GI toxicity occurred in three patients in the standard‐dose group and did not occur in the high‐dose group.ConclusionsPatients treated with dose‐escalated MRgRT demonstrated improved OS. Prospective evaluation of high‐dose RT regimens with standardized treatment parameters in inoperable pancreatic cancer patients is warranted.
Highlights
Radiation therapy (RT) is controversial in the treatment of inoperable pancreatic cancer
The results of the phase III randomized LAP07 trial illustrate that conventional doses of 3D conformal radiation (3DCRT) do not confer an overall survival (OS) advantage over chemotherapy alone in locally advanced pancreatic cancer (LAPC).[1]
Krishnan et al have demonstrated that dose escalation using simultaneous integrated boost (SIB) with intensity‐modulated radiation therapy (IMRT) improved survival and local control in LAPC compared to standard radiotherapy doses in a single‐institution retrospective study.[11]
Summary
Radiation therapy (RT) is controversial in the treatment of inoperable pancreatic cancer. The results of the phase III randomized LAP07 trial illustrate that conventional doses of 3D conformal radiation (3DCRT) do not confer an overall survival (OS) advantage over chemotherapy alone in locally advanced pancreatic cancer (LAPC).[1] Investigators have evaluated RT techniques other than 3DCRT to improve outcomes. We evaluated outcomes of inoperable pancreatic cancer patients treated using MRgRT with and without dose escalation. Methods: We reviewed 44 patients with inoperable pancreatic cancer treated with MRgRT.
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.
