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Clinical Trial
. 2012 Jun 20:7:98.
doi: 10.1186/1748-717X-7-98.

Incorporating breath holding and image guidance in the adjuvant gastric cancer radiotherapy: a dosimetric study

Weigang Hu  1 , Jinsong Ye, Jiazhou Wang, Qing Xu, Zhen Zhang
Affiliations
Clinical Trial

Incorporating breath holding and image guidance in the adjuvant gastric cancer radiotherapy: a dosimetric study

Weigang Hu et al. Radiat Oncol. .

Abstract

Background: The respiratory related target motion and setup error will lead to a large margin in the gastric radiotherapy. The purpose of this study is to investigate the dosimetric benefit and the possibility of incorporating the breath-hold (BH) technique with online image-guided radiotherapy in the adjuvant gastric cancer radiotherapy.

Methods: Setup errors and target motions of 22 post-operative gastric cancer patients with surgical clips were analyzed. Clips movement was recorded using the digital fluoroscopics and the probability distribution functions (pdf) of the target motions were created for both the free breathing (FB) and BH treatment. For dosimetric comparisons, two intensity-modulated radiotherapy (IMRT) treatment plans, i.e. the free breathing treatment plan (IMRT(FB)) and the image-guided BH treatment plan (IMRT(IGBH)) using the same beam parameters were performed among 6 randomly selected patients. Different margins for FB and BH plans were derived. The plan dose map was convoluted with various pdfs of the setup errors and the target motions. Target coverage and dose to organs at risk were compared and the dose-escalation probability was assessed.

Results: The mean setup errors were 1.2 mm in the superior-inferior (SI), 0.0 mm in the left-right (LR), and 1.4 mm in the anterior-posterior (AP) directions. The mean target motion for the free breathing (vs. BH) was 11.1 mm (vs. 2.2 mm), 1.9 mm (vs. 1.1 mm), and 5.5 mm (vs. 1.7 mm) in the SI, LR, and AP direction, respectively. The target coverage was comparable for all the original plans. IMRT(IGBH) showed lower dose to the liver compared with IMRT(FB) (p = 0.01) but no significant difference in the kidneys. Convolved IMRTIGBH showed better sparing in kidneys (p < 0.01) and similar in liver (p = 0.08).

Conclusions: Combining BH technique with online image guided IMRT can minimize the organ motion and improve the setup accuracy. The dosimetric comparison showed the dose could be escalated to 54 Gy without increasing the critical organs toxicities, although further clinical data is needed.

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Figures

Figure 1
Figure 1
The diaphragm of this study.
Figure 2
Figure 2
The clips motion trajectory after their positions on each frame were projected on to the reference frame (A: AP direction; B: LR direction) and the displacement of the centroid clips versus time in SI, LR, and AP directions (C).D: Weekly Probability Distribution Functions In The Si, Lr And Ap Direction For The Free Breathing Treatment.
Figure 3
Figure 3
The dose distributions of one patient in free breath mode without (A) and with (B) convolving setup error and target motion and in combining ABC and online IGRT without (C) and with (D) convolving residual target motion.
See this image and copyright information in PMC

References

    1. Moertel CG, Childs DS, Reitemeier RJ, Colby MY, Holbrook MA. Combined 5-fluorouracil and supervoltage radiation therapy of locally unresectable gastrointestinal cancer. Lancet. 1969;2:865–867. - PubMed
    1. Macdonald JS, Benedetti J, Smalley S. Chemoradiation of resected gastric cancer: a 10-year follow-up of the phase III trial INT0116 (SWOG9008)[abstract] J Clin Oncol. 2009;27:4515. doi: 10.1200/JCO.2008.19.6873. - DOI - PMC - PubMed
    1. Bockbrader M, Kim E. Role of intensity-modulated radiation therapy in gastrointestinal cancer. Expert Rev Anticancer Ther. 2009;9:637–647. doi: 10.1586/era.09.16. - DOI - PubMed
    1. Minn AY, Hsu A, La T, Kunz P, Fisher GA, Ford JM, Norton JA, Visser B, Goodman KA, Koong AC, Chang DT. Comparison of intensity-modulated radiotherapy and 3-dimensional conformal radiotherapy as adjuvant therapy for gastric cancer. Cancer. 2010;116:3943–3952. doi: 10.1002/cncr.25246. - DOI - PubMed
    1. Dickie CI, Parent AL, Chung PW, Catton CN, Craig T, Griffin AM, Panzarella T, Ferguson PC, Wunder JS, Bell RS, Sharpe MB, O'Sullivan B. Measuring interfractional and intrafractional motion with cone beam computed tomography and an optical localization system for lower extremity soft tissue sarcoma patients treated with preoperative intensity-modulated radiation therapy. Int J Radiat Oncol Biol Phys. 2010;78:1437–1444. doi: 10.1016/j.ijrobp.2009.09.054. - DOI - PubMed

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