Journal of Radiation Research and Radiation Proces ›› 2016, Vol. 34 ›› Issue (4): 40201-040201.doi: 10.11889/j.1000-3436.2016.rrj.34.040201

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Quality control test and assessment of helical tomotherapy unit

ZHAI Zipo1, ZHAI Hezheng2, MA Yongzhong3, PENG Junzhe1, ZHAO Zhixin2   

  1. 1 Hunan Prevention and Treatment Institute for Occupational Disease, Changsha 410007, China;
    2 Institute of Radiation Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin 300192, China;
    3 Beijing Centers for Diseases Control and Prevention(CDC), Beijing 100013, China
  • Received:2016-04-14 Revised:2016-06-23 Online:2016-08-20 Published:2016-08-18
  • Supported by:

    Supported by Peking Union Medical College Peking Union Youth Fund (3332015101)


The investigation was conducted to evaluate the performance of the first tomotherapy (TOMO) in hunan to provide guarantee for clinical radiotherapy. PTW UNIDOS dosimeter and two ionization chambers (0.6 cm3 and 0.125 cm3) were employed, together with MatrixXX, EBT3 films, and phantom, to test ten of the key indicators of TOMO, in accordance with the standards Specifications for Quality Control Test of Helical Tomotherapy Unit. The results showed that there were some deviations in the indicators:a deviation less than 0.1% for static output dose, a deviation of -1.4% between the rotary output dose and the planned dose; a deviation of 0.3% for ray quality from the nominal value; a discrepancy of 0.7% for the transverse beam profile; a discrepancy of 0.5 mm for the FWHM of the longitudinal beam profiles; a deviation of 0.6 mm for multi-leaf collimator; a deviation less than 1.0 mm for virtual indication of green laser lights on X-axis, Y-axis and Z-axis; a deviation lower than 1.0 mm between red laser light indication and movement of treatment couch; a 0.6 mm of synchronization deviation between couch and gantry rotation. So the 10 key indicators inspected are in line with the limits and indexes specified in Specifications for Quality Control Test of Helical Tomotherapy Unit. However, consistent inspection of the apparatus is needed.

Key words: Helical Tomotherapy, Quality control, Absorbed dose, Percent depth dose

CLC Number: 

  • R145