A New Infrared-Based Design for Measuring the Source to Skin Distance

Year 2019, Volume: 9 Issue: 2, 269 - 276, 01.06.2019

Yalcin Isler Alpman Manalp

https://doi.org/10.7212/zkufbd.v9i2.1448

Abstract

Cancer is a major public health problem worldwide. There are many types of cancer therapy methods including the radiotherapy. In radiotherapy, positioning the patient to a consistent treatment location is significantly crucial to receive an effective dose, which closely affects the success of the therapy. The most commonly used parameter for ensuring the effective patient position is the source to skin distance SSD . In this study, an infrared-based SSD measuring device is developed and its feasibility and accuracy are tested. The prototype of the infrared SSD measuring device IRD is composed of two major parts: a measuring distance sensor unit and a control unit. The microcontroller-based control unit displays the measurement in millimeters and transmits it to a computer via serial port. The SSD measurement experiments were conducted on a Siemens Primus Linear Accelerator with a full-sized male phantom. Thirty measurements were conducted at different gantry angles for anatomic locations in order to determine the mean values and standard deviations. This device was tuned by a conventional mechanical ruler with an accuracy of 0.7324 mm. The results revealed that the proposed device gives more consistent and accurate readouts with smaller variations in all body functions than other devices.

Keywords

Patient setup, Positioning error, Source-to-skin distance, Linear accelerators

Kaynak Cilt Mesafesi Ölçümüne Yönelik Kızılötesi Tabanlı Yeni Bir Tasarım

Abstract

Kanser dünya genelindeki başlıca toplum sağlığı sorunudur. Radyoterapi de dahil olmak üzere birçok kanser tedavi yöntemi bulunmaktadır. Radyoterapide sabit bir tedavi noktasına hastayı konumlandırmak tedavinin başarımını doğrudan etkileyen etkin doz alımı için oldukça önemlidir. Etkili hasta konumunu garanti altına almak için en çok kullanılan parametre kaynak cilt mesafesidir SSD . Bu çalışmada, kızılötesi tabanlı bir SSD ölçüm cihazı geliştirilerek kullanışlılığı ve doğruluğu test edilmiştir. Kızılötesi SSD ölçüm cihazının IRD örneği iki ana bileşenden oluşmaktadır: bir mesafe algılayıcısı ve bir kontrol birimi. Mikrodenetleyici tabanlı kontrol birimi ölçümü milimetre cinsinden ekranda gösterir ve seri port aracılığıyla bir bilgisayara aktarmaktadır. SSD ölçüm deneyleri gerçek boyutlu bir erkek model üzerinde Siemens Primus marka lineer algılayıcı ile gerçekleştirilmiştir. Farklı cihaz açıları ve anatomik konumların her biri için otuzar ölçüm alınarak ortalama ve standart sapmalar hesaplanmıştır. Cihaz geleneksel mekanik cetvel ile 0,7324 mm doğrulukta kalibre edilmiştir. Elde edilen sonuçlara göre, geliştirilen cihaz tüm vücut konumları için benzerlerinden daha düşük sapmalarla daha yüksek doğrulukta ölçüm sonuçları vermektedir

Keywords

Lineer hızlandırıcılar, Hasta düzeni, Konumlama hatası, Kaynak-cilt mesafesi

References

• Acroname Robotics. 2013. Linearizing Sharp Ranger Data. https://acroname.com/articles/linearizing-sharp-ranger-data
• Ahn, PHK. 2016. Patient positioning system and methods for diagnostic radiology and radiotherapy. United States Patent Office US 9433387, 6 September 2016.
• Akgul, A. 2003. Statistical Analysis Techniques in Medical Researches: SPSS Experiments. Ankara: Seckin Yayincilik, Turkey, (in Turkish).
• Birkenbach, R., Manus, J. 2018. Patient positioning system with an electromagnetic field generator of an electromagnetic tracking system. United States Patent Office US 9918797, 20 March 2018.
• National Cancer Institute. 2017. Types of Cancer Treatment, https://www.cancer.gov/about-cancer/treatment/types, last updated April 6, 2017 and last visited February 13, 2019.
• National Cancer Institute. 2018. Radiation Therapy to Treat Cancer, https://www.cancer.gov/about-cancer/treatment/ types/radiation-therapy, last reviewed May 1, 2018, and last visited February 13, 2019.
• Padilla, L., Kang, H., Washington, M., Hasan, Y., Chmura, S., Al-Hallaq, H. 2014. Assessment of interfractional variation of the breast surface following conventional patient positioning for whole-breast radiotherapy. J. Appl. Clin. Med. Phys., 15(5): 177-189.
• Rehammar, JC., Jensen, MB., McGale, P., Lorenzen, EL., Taylor, C., Darby, SC., Videbaek, L., Wang, Z., Ewertza, M. 2017. Risk of heart disease in relation to radiotherapy and chemotherapy with anthracyclines among 19464 breast cancer patients in Denmark 1977-2005. Radiother Oncol., 123(2): 299-305.
• Siegel, RL., Miller, K.D., Jemal, A. 2016. Cancer statistics 2016. CA. Cancer J. Clin., 66(1): 7-30.
• Siiskonen, T., Kaijaluoto, S., Florea, T. 2017. Imaging practices and radiation doses from imaging in radiotherapy. Physica. Med. 42: 247-252.
• Stanescu, T., Dolg, V., Mondoc, A. 2014. Random issues in workspace analysis for a mobile robot. AIP Conf Proc 1637(1): 1254.
• Us, B., Pepele, EK. 2017. An experimental study on the determination of gantry angle and SSD dependencies of TLD and MOSFET dosimeter systems. Int. J. Radiat. Res., 15(1): 117-121.
• Viergever, MA., Maintz, JBA., Klein, S., Murphy, K., Staring, M., Pluim, JPW. 2016. A survey of medical image registration. Med. Image Anal., 33: 140-144.
• Walter, F., Freislederer, P., Belka, C., Heinz, C., Sohn, M., Roeder, F. 2016. Evaluation of daily patient positioning for radiotherapy with a commercial 3D surface-imaging system (Catalyst). Radiat. Oncol., 11: 154.1-8.
• Xing, L. 2000. Dosimetric effects of patient displacement and collimator and gantry angle misalignment on intensity modulated radiation therapy. Radiat. Oncol., 56(1): 97-108.