Faculty Collaboration Database

Online adaptive replanning method for prostate radiotherapy. Int J Radiat Oncol Biol Phys 2010 Aug 01;77(5):1561-72

Date

04/07/2010

Pubmed ID

20362401

DOI

10.1016/j.ijrobp.2009.10.013

Scopus ID

2-s2.0-77955506120 (requires institutional sign-in at Scopus site)   81 Citations

Abstract

PURPOSE: To report the application of an adaptive replanning technique for prostate cancer radiotherapy (RT), consisting of two steps: (1) segment aperture morphing (SAM), and (2) segment weight optimization (SWO), to account for interfraction variations.

METHODS AND MATERIALS: The new "SAM+SWO" scheme was retroactively applied to the daily CT images acquired for 10 prostate cancer patients on a linear accelerator and CT-on-Rails combination during the course of RT. Doses generated by the SAM+SWO scheme based on the daily CT images were compared with doses generated after patient repositioning using the current planning target volume (PTV) margin (5 mm, 3 mm toward rectum) and a reduced margin (2 mm), along with full reoptimization scans based on the daily CT images to evaluate dosimetry benefits.

RESULTS: For all cases studied, the online replanning method provided significantly better target coverage when compared with repositioning with reduced PTV (13% increase in minimum prostate dose) and improved organ sparing when compared with repositioning with regular PTV (13% decrease in the generalized equivalent uniform dose of rectum). The time required to complete the online replanning process was 6 +/- 2 minutes.

CONCLUSION: The proposed online replanning method can be used to account for interfraction variations for prostate RT with a practically acceptable time frame (5-10 min) and with significant dosimetric benefits. On the basis of this study, the developed online replanning scheme is being implemented in the clinic for prostate RT.

Author List

Ahunbay EE, Peng C, Holmes S, Godley A, Lawton C, Li XA

Author

Ergun Ahunbay PhD Professor in the Radiation Oncology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Algorithms
Femur Head
Humans
Male
Movement
Prostate
Prostatic Neoplasms
Pubic Bone
Radiation Injuries
Radiography
Radiotherapy Planning, Computer-Assisted
Radiotherapy, Computer-Assisted
Radiotherapy, Intensity-Modulated
Rectum
Time Factors
Urinary Bladder