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Application of Volumetric Modulated Arc Therapy and Simultaneous Integrated Boost Techniques to Prepare "Safe Margin" in the Rabbit VX2 Limb Tumor Model.

Wang CW, Zhou Y, Bai JP, Liu H, Liu Y, Shi GL, Ding JJ, Ma DH, Li WT, Xie PM, Yan Y - Med. Sci. Monit. (2015)

Bottom Line: After radiotherapy, the two groups showed a significant difference in the GTVboost area.The 3D-PDA observation showed that tumor vascular structures decreased significantly.The formation of a necrotic zone can be effectively defined as safe margin in the GTVboost area. showing potential clinical applicability.

View Article: PubMed Central - PubMed

Affiliation: Department of Bone and Soft Tissue, The Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China (mainland).

ABSTRACT

Background: In this study, we aimed to establish the rabbit VX2 limb tumor model, and then prepare a "necrotic zone" as a safe margin by volumetric modulated arc therapy and simultaneous integrated boost (VMAT-SIB) technique applied in the areas where the tumor is located adjacent to the bone (GTVboost area).

Material and methods: Rabbits in the control group (n=10) were not treated, while those in the test group (n=10) were treated with the SIB schedule delivering a dose of 40Gy, 35Gy, 30Gy, and 25Gy to the GTVboost, GTV (gross tumor volume), CTV (clinical target volume), and PTV (planning target volume) in 10 fractions. Magnetic resonance diffusion-weighted imaging (MRDWI), 3-dimensional power Doppler angiography (3D-PDA), and histological changes were observed after radiotherapy.

Results: After radiotherapy, the two groups showed a significant difference in the GTVboost area. In the test group, the tumor necrosis showed a significantly low signal in DWI and high signal in apparent diffusion coefficient (ADC) maps. The 3D-PDA observation showed that tumor vascular structures decreased significantly. Histological analysis demonstrated that a necrotic zone could be generated in the GTVboost area, and microscopic examination observed cell necrosis and fibroplasia.

Conclusions: This studies demonstrated the feasibility of using VMAT-SIB technique in the rabbit VX2 limb tumor model. The formation of a necrotic zone can be effectively defined as safe margin in the GTVboost area. showing potential clinical applicability.

No MeSH data available.


Related in: MedlinePlus

(A) Tumor adjacent to the NVB and bone. (B) Enhancing radiation at GTVboost area using SIB.
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f1-medscimonit-21-2397: (A) Tumor adjacent to the NVB and bone. (B) Enhancing radiation at GTVboost area using SIB.

Mentions: Based on our imaging studies of tumors resected from high-grade limb STS cases, we found that some tumors did not invade the NVB or bone, but were located adjacent to these structures (Figure 1A). Thus, we hypothesized that STS is an irregularly shaped solid tumor with one surface or an edge adjacent to the NVB or bones. Using VMAT-SIB, we could increase the radiation dose in the areas where the tumor is located adjacent to the bone (i.e., when the delineated the target volume is defined as GTVboost area) (Figure 1B). This enhances local tissue injury and a necrotic zone could be generated (i.e., macroscopic and microscopic observed the cell necrosis in the GTVboost area).We defined such necrotic zone as “safe margin”.


Application of Volumetric Modulated Arc Therapy and Simultaneous Integrated Boost Techniques to Prepare "Safe Margin" in the Rabbit VX2 Limb Tumor Model.

Wang CW, Zhou Y, Bai JP, Liu H, Liu Y, Shi GL, Ding JJ, Ma DH, Li WT, Xie PM, Yan Y - Med. Sci. Monit. (2015)

(A) Tumor adjacent to the NVB and bone. (B) Enhancing radiation at GTVboost area using SIB.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4544349&req=5

f1-medscimonit-21-2397: (A) Tumor adjacent to the NVB and bone. (B) Enhancing radiation at GTVboost area using SIB.
Mentions: Based on our imaging studies of tumors resected from high-grade limb STS cases, we found that some tumors did not invade the NVB or bone, but were located adjacent to these structures (Figure 1A). Thus, we hypothesized that STS is an irregularly shaped solid tumor with one surface or an edge adjacent to the NVB or bones. Using VMAT-SIB, we could increase the radiation dose in the areas where the tumor is located adjacent to the bone (i.e., when the delineated the target volume is defined as GTVboost area) (Figure 1B). This enhances local tissue injury and a necrotic zone could be generated (i.e., macroscopic and microscopic observed the cell necrosis in the GTVboost area).We defined such necrotic zone as “safe margin”.

Bottom Line: After radiotherapy, the two groups showed a significant difference in the GTVboost area.The 3D-PDA observation showed that tumor vascular structures decreased significantly.The formation of a necrotic zone can be effectively defined as safe margin in the GTVboost area. showing potential clinical applicability.

View Article: PubMed Central - PubMed

Affiliation: Department of Bone and Soft Tissue, The Affiliated Tumor Hospital of Xinjiang Medical University, Urumqi, Xinjiang, China (mainland).

ABSTRACT

Background: In this study, we aimed to establish the rabbit VX2 limb tumor model, and then prepare a "necrotic zone" as a safe margin by volumetric modulated arc therapy and simultaneous integrated boost (VMAT-SIB) technique applied in the areas where the tumor is located adjacent to the bone (GTVboost area).

Material and methods: Rabbits in the control group (n=10) were not treated, while those in the test group (n=10) were treated with the SIB schedule delivering a dose of 40Gy, 35Gy, 30Gy, and 25Gy to the GTVboost, GTV (gross tumor volume), CTV (clinical target volume), and PTV (planning target volume) in 10 fractions. Magnetic resonance diffusion-weighted imaging (MRDWI), 3-dimensional power Doppler angiography (3D-PDA), and histological changes were observed after radiotherapy.

Results: After radiotherapy, the two groups showed a significant difference in the GTVboost area. In the test group, the tumor necrosis showed a significantly low signal in DWI and high signal in apparent diffusion coefficient (ADC) maps. The 3D-PDA observation showed that tumor vascular structures decreased significantly. Histological analysis demonstrated that a necrotic zone could be generated in the GTVboost area, and microscopic examination observed cell necrosis and fibroplasia.

Conclusions: This studies demonstrated the feasibility of using VMAT-SIB technique in the rabbit VX2 limb tumor model. The formation of a necrotic zone can be effectively defined as safe margin in the GTVboost area. showing potential clinical applicability.

No MeSH data available.


Related in: MedlinePlus