PURPOSE:To determine the extent of gold fiducial marker (FM) migration in patients treated for prostate cancer with concurrent androgen deprivation and external-beam radiation therapy (EBRT).
METHODS AND MATERIALS: Three or 4 gold FMs were implanted in 37 patients with prostate adenocarcinoma receiving androgen deprivation therapy (ADT) in conjunction with 70-78 Gy. Androgen deprivation therapy was started a median of 3.9 months before EBRT (range, 0.3-12.5 months). To establish the extent of FM migration, the distance between each FM was calculated for 5-8 treatments once per week throughout the EBRT course. For each treatment, the distance between FMs was compared with the distance from the digitally reconstructed radiographs generated from the planning CT. A total of 281 treatments were analyzed.
RESULTS: The average daily migration was 0.8 ± 0.3 mm, with distances ranging from 0.2 mm-2.6 mm. Two of the 281 assessed treatments (0.7%) showed migrations >2 mm. No correlation between FM migration and patient weight or time delay between ADT and start of EBRT was found. There was no correlation between the extent of FM migration and prostate volume.
CONCLUSION: This is the largest report of implanted FM migration in patients receiving concomitant ADT. Only 0.7% of the 281 treatments studied had significant marker migrations (>2 mm) throughout the course of EBRT. Consequently, the use of implanted FMs in these patients enables accurate monitoring of prostate gland position during treatment.
Written by:
Tiberi DA, Carrier JF, Beauchemin MC, Nguyen TV, Béliveau-Nadeau D, Taussky D. Are you the author?
Département de Radio-Oncologie, Centre hospitalier de l'Université de Montréal-Hôpital Notre-Dame, Montréal, Quebec, Canada.
Reference: Int J Radiat Oncol Biol Phys. 2012 Apr 27. Epub ahead of print.
doi: 10.1016/j.ijrobp.2012.02.016
PubMed Abstract
PMID: 22541962
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