Room: Exhibit Hall
Purpose: By making the equivalent lung phantom of the personalized tissue , compared the differences among the Monte Carlo algorithm (MC) , the Pencil beam convolution (PBC) and the Collapsed cone convolution (CCC) of Swedish ELEKTA Monaco5.11 TPS in the calculation of 3D conformal radiotherapy (3D-CRT) plan.
Methods: Using 3D printing and perfusion to make equivalent lung phantom of the personalized tissue, scanned by CT (HiSpeed Dual, GE, Germany) and transmitted to the TPS (Monaco 5.11, ELEKTA, Swedish), outline the target area and develop a suitable radiotherapy plan. The tumor tissue, normal lung tissue and spinal cord were three measuring points inserted into the ionization chamber (30013, PTW, Germany) and scanned by CT Using image fusion techniques to match CT images, unify the target area, determine the position of measurement point in the image, calculate and compare the results of the three algorithms. The radiotherapy program was performed under a medical linear accelerator (Precise Treatment System, ELEKTA, Swedish) and recorded and compared by using a dosimeter (UNIDOS E, PTW, Germany).
Results: Both MC and CCC overestimated the dose of tumor tissue, normal lung tissue and spinal cord. MC calculated the dose of tumor tissue higher than CCC, but the dose of lung normal tissue and spinal cord was lower than CCC. The PBC overestimates the dose of tumor tissue and underestimates the dose of normal lung tissue and spinal cord.
Conclusion: The equivalent model of individualized tissue is conducive to the preliminary validation of the patient's individual radiotherapy plan, and the accuracy of different algorithms is compared. For the result of this experiment, the PBC algorithm is not recommended.
Funding Support, Disclosures, and Conflict of Interest: Acknowledgement Fund Projects: National Key Research and Development Project (2016YFC0103400). J. Q. was supported by the Taishan Scholars Program of Shandong Province .
3D, Absolute Dosimetry, Phantoms
TH- Radiation dose measurement devices: Phantoms for dosimetric measurement