A Clinical Dosimetry Analysis of Total Body Irradiation for Leukemia PatientsReport as inadecuate




A Clinical Dosimetry Analysis of Total Body Irradiation for Leukemia Patients - Download this document for free, or read online. Document in PDF available to download.

Background andPurpose: To perform a retrospective invivo dosimetry study of 129 total body irradiation TBI on leukemia andbone marrow transplant patients treated in our clinic from 2008 to 2011 and tofind out if there is any indication of the necessity of developing a newefficient TBI approach. Materials and Methods: The in vivo dosimetry data of 129 patients treated with TBI between2008 and 2011 were retrieved from the database and analyzed. These patientswere mostly treated with the regime of a single fraction or 6 fractions withsome exceptions of 8-fraction or 2-fraction treatments depending on theprotocols that were applied. For every fraction of treatment, 10 pairs of diodedosimeters were used to monitor the doses to the midline of head, neck, arms, mediastinum,left lung, right lung, umbilicus, thigh, knee, and ankle for both AP and PAfields. The doses to the midline of the above body parts were considered to bethe average of the AP and PA readings of each diode pair. Dose deviation fromthe prescribed value for each body part was studied by plotting the histogramof the frequency versus deviation and comparing this with the dose delivered tothe midline of the umbilicus to where the dose was prescribed. The correlationof dose deviation to body part thickness was also studied. By studying the dosedeviations, we can find the uniformity of general dose distributions forconventional TBI treatments. Results: The retrospective dosimetry study of the129 TBI patient treatments indicates that for most of the patients treated inour clinic, the doses receivedby different body parts monitored with invivo dosimetry were within the window of 10% difference from the prescribeddose. The inhomogeneity of dose on different body parts could be manuallyimproved by using compensators, but themethod is cumbersome and time consuming. The dose deviation in many histogramsranging from about ?10% to 10% indicates some incongruity of dose distribution.This could be due to the method of using lead compensators for a manual doseadjustment which could not ideally compensate for different body thicknesseseverywhere. Conclusions: The conventional TBI could give uniform dose to the major body partsunder the online in vivo dosimetrymonitoring at the level of 10%, but the treatment procedure is cumbersome andtime consuming. This implies the importance of developing a new and efficientTBI method by adopting modern radiation therapy technique.

KEYWORDS

Total Body Irradiation TBI; In Vivo Dosimetry; Lung Block; Compensators; Patient Setup; Treatment Planning

Cite this paper

L. Lu, J. Filippi, A. Patel, N. Gupta, M. Weldon, J. Woollard, A. Ayan, Y. Rong, D. Martin, C. Pelloski and M. Welliver -A Clinical Dosimetry Analysis of Total Body Irradiation for Leukemia Patients,- International Journal of Medical Physics, Clinical Engineering and Radiation Oncology, Vol. 3 No. 1, 2014, pp. 31-42. doi: 10.4236-ijmpcero.2014.31006.





Author: Lanchun Lu, Jonathan Filippi, Akshi Patel, Nilendu Gupta, Michael Weldon, Jeffery Woollard, Ahmet Ayan, Yi Rong, Douglas Martin,

Source: http://www.scirp.org/



DOWNLOAD PDF




Related documents