Journal of Medical Physics
TECHNICAL NOTE
Year
: 2014  |  Volume : 39  |  Issue : 1  |  Page : 40--43

Estimation of dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiothearpy - A phantom dosimetric study with radiochromic film


Rajesh Ashok Kinhikar1, Chandrashekhar M Tambe1, Kalpana Patil1, Mahadev Mandavkar1, Deepak D Deshpande1, Rajendra Gujjalanavar2, Prabha Yadav2, Ashwini Budrukkar3 
1 Department of Medical Physics, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
2 Department of Plastic Surgery, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India
3 Department of Radiation Oncology, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India

Correspondence Address:
Rajesh Ashok Kinhikar
Department of Medical Physics, Tata Memorial Hospital, Dr. Ernest Borges Road Parel, Maharashtra, Mumbai - 400 012
India

The objective of this study was to investigate the dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiotherapy. The influence of titanium-mandibular plate with the screws on radiation dose was tested on four real bones from mandible with the metal and screws fixed. Radiochromic films were used for dosimetry. The bone and metal were inserted through the film at the center symmetrically. This was then placed in a small jig (7 cm × 7 cm × 10 cm) to hold the film vertically straight. The polymer granules (tissue-equivalent) were placed around the film for homogeneous scatter medium. The film was irradiated with 6 MV X-rays for 200 monitor units in Trilogy linear accelerator for 10 cm × 10 cm field size with source to axis distance of 100 cm at 5 cm. A single film was also irradiated without any bone and metal interface for reference data. The absolute dose and the vertical dose profile were measured from the film. There was 10% dose enhancement due to the backscatter radiation just adjacent to the metal-bone interface for all the materials. The extent of the backscatter effect was up to 4 mm. There is significant higher dose enhancement in the soft tissue/skin due to the backscatter radiation from the metallic components in the treatment region.


How to cite this article:
Kinhikar RA, Tambe CM, Patil K, Mandavkar M, Deshpande DD, Gujjalanavar R, Yadav P, Budrukkar A. Estimation of dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiothearpy - A phantom dosimetric study with radiochromic film.J Med Phys 2014;39:40-43


How to cite this URL:
Kinhikar RA, Tambe CM, Patil K, Mandavkar M, Deshpande DD, Gujjalanavar R, Yadav P, Budrukkar A. Estimation of dose enhancement to soft tissue due to backscatter radiation near metal interfaces during head and neck radiothearpy - A phantom dosimetric study with radiochromic film. J Med Phys [serial online] 2014 [cited 2019 Jul 19 ];39:40-43
Available from: http://www.jmp.org.in/article.asp?issn=0971-6203;year=2014;volume=39;issue=1;spage=40;epage=43;aulast=Kinhikar;type=0