Limits...
Intensity-modulated radiation therapy using static ports of tomotherapy (TomoDirect): comparison with the TomoHelical mode.

Murai T, Shibamoto Y, Manabe Y, Murata R, Sugie C, Hayashi A, Ito H, Miyoshi Y - Radiat Oncol (2013)

Bottom Line: The purpose of this study was to evaluate the characteristics of TomoDirect plans compared to conventional TomoHelical plans.Treatment time did not differ significantly between the thoracic wall and lung plans.Prostate cancers should be treated with the TomoHelical mode.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. taro8864@yahoo.co.jp

ABSTRACT

Purpose: With the new mode of Tomotherapy, irradiation can be delivered using static ports of the TomoDirect mode. The purpose of this study was to evaluate the characteristics of TomoDirect plans compared to conventional TomoHelical plans.

Methods: TomoDirect and TomoHelical plans were compared in 46 patients with a prostate, thoracic wall or lung tumor. The mean target dose was used as the prescription dose. The minimum coverage dose of 95% of the target (D95%), conformity index (CI), uniformity index (UI), dose distribution in organs at risk and treatment time were evaluated. For TomoDirect, 2 to 5 static ports were used depending on the tumor location.

Results: For the prostate target volume, TomoDirect plans could not reduce the rectal dose and required a longer treatment time than TomoHelical. For the thoracic wall target volume, the V5Gy of the lung or liver was lower in TomoDirect than in TomoHelical (p = 0.02). For the lung target volume, TomoDirect yielded higher CI (p = 0.009) but smaller V5Gy of the lung (p = 0.005) than TomoHelical. Treatment time did not differ significantly between the thoracic wall and lung plans.

Conclusion: Prostate cancers should be treated with the TomoHelical mode. Considering the risk of low-dose radiation to the lung, the TomoDirect mode could be an option for thoracic wall and lung tumors.

Show MeSH

Related in: MedlinePlus

Lung target volume. (a) TomoHelical plan. (b) TomoDirect plan.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3643840&req=5

Figure 4: Lung target volume. (a) TomoHelical plan. (b) TomoDirect plan.

Mentions: In the lung plans (Figure 4), D95%, UI and MLD did not differ significantly between the two modes, but the CI in TomoDirect was inferior to that in TomoHelical (3.24 ± 0.30 vs. 2.33 ± 0.13, p = 0.009). The V5 Gy of the lung was smaller than that in TomoHelical (30 ± 3% vs. 43 ± 3%, p = 0.005). Beam-on time did not differ significantly between TomoDirect and TomoHelical in thoracic wall and lung plans (Table 3).


Intensity-modulated radiation therapy using static ports of tomotherapy (TomoDirect): comparison with the TomoHelical mode.

Murai T, Shibamoto Y, Manabe Y, Murata R, Sugie C, Hayashi A, Ito H, Miyoshi Y - Radiat Oncol (2013)

Lung target volume. (a) TomoHelical plan. (b) TomoDirect plan.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643840&req=5

Figure 4: Lung target volume. (a) TomoHelical plan. (b) TomoDirect plan.
Mentions: In the lung plans (Figure 4), D95%, UI and MLD did not differ significantly between the two modes, but the CI in TomoDirect was inferior to that in TomoHelical (3.24 ± 0.30 vs. 2.33 ± 0.13, p = 0.009). The V5 Gy of the lung was smaller than that in TomoHelical (30 ± 3% vs. 43 ± 3%, p = 0.005). Beam-on time did not differ significantly between TomoDirect and TomoHelical in thoracic wall and lung plans (Table 3).

Bottom Line: The purpose of this study was to evaluate the characteristics of TomoDirect plans compared to conventional TomoHelical plans.Treatment time did not differ significantly between the thoracic wall and lung plans.Prostate cancers should be treated with the TomoHelical mode.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Radiology, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya 467-8601, Japan. taro8864@yahoo.co.jp

ABSTRACT

Purpose: With the new mode of Tomotherapy, irradiation can be delivered using static ports of the TomoDirect mode. The purpose of this study was to evaluate the characteristics of TomoDirect plans compared to conventional TomoHelical plans.

Methods: TomoDirect and TomoHelical plans were compared in 46 patients with a prostate, thoracic wall or lung tumor. The mean target dose was used as the prescription dose. The minimum coverage dose of 95% of the target (D95%), conformity index (CI), uniformity index (UI), dose distribution in organs at risk and treatment time were evaluated. For TomoDirect, 2 to 5 static ports were used depending on the tumor location.

Results: For the prostate target volume, TomoDirect plans could not reduce the rectal dose and required a longer treatment time than TomoHelical. For the thoracic wall target volume, the V5Gy of the lung or liver was lower in TomoDirect than in TomoHelical (p = 0.02). For the lung target volume, TomoDirect yielded higher CI (p = 0.009) but smaller V5Gy of the lung (p = 0.005) than TomoHelical. Treatment time did not differ significantly between the thoracic wall and lung plans.

Conclusion: Prostate cancers should be treated with the TomoHelical mode. Considering the risk of low-dose radiation to the lung, the TomoDirect mode could be an option for thoracic wall and lung tumors.

Show MeSH
Related in: MedlinePlus