Abstract
The application of intensity-modulated radiation therapy (IMRT) has enabled the delivery of high doses to the target volume while sparing the surrounding normal tissues. The drawbacks of intensity modulation, as implemented using a computer-controlled multileaf collimator (MLC), are the larger number of monitor units (MUs) and longer beam-on time as compared with conventional radiotherapy. Additionally, IMRT uses more beam directions - typically 5-9 for prostate treatment - to achieve highly conformal dose and normal-tissue sparing. In the present work, we study radiation-induced cancer risks attributable to IMRT delivery using MLC for prostate patients. Whole-body computed tomography scans were used in our study to calculate (according to report no. 116 from the National Council on Radiation Protection and Measurements) the effective dose equivalent received by individual organs. We used EGS4 and MCSIM to compute the dose for IMRT and three-dimensional conformal radiotherapy. The effects of collimator rotation, distance from the treatment field, and scatter and leakage contribution to the Whole-body dose were investigated. We calculated the whole-body dose equivalent to estimate the increase in the risk of secondary malignancies. Our results showed an overall doubling in the risk of secondary malignancies from the application of IMRT as compared with conventional radiotherapy. This increase in the risk of secondary malignancies is not necessarily related to a relative increase in MUs. The whole-body dose equivalent was also affected by collimator rotation, field size, and the energy of the photon beam. Smaller field sizes of low-energy photon beams (that is, 6 MV) with the MLC axis along the lateral axis of the patient resulted in the lowest whole-body dose. Our results can be used to evaluate the risk of secondary malignancies for prostate IMRT patients.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 14-27 |
| Number of pages | 14 |
| Journal | Journal of Applied Clinical Medical Physics |
| Volume | 8 |
| Issue number | 4 |
| State | Published - Sep 2007 |
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Keywords
- IMRT
- Prostate radiation therapy
- Secondary malignancies
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Radiation
- Instrumentation
Cite this
Monte Carlo determination of radiation-induced cancer risks for prostate patients undergoing intensity-modulated radiation therapy. / Stathakis, Sotirios; Li, Jinsheng; Ma, Charlie C M.
In: Journal of Applied Clinical Medical Physics, Vol. 8, No. 4, 09.2007, p. 14-27.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Monte Carlo determination of radiation-induced cancer risks for prostate patients undergoing intensity-modulated radiation therapy
AU - Stathakis, Sotirios
AU - Li, Jinsheng
AU - Ma, Charlie C M
PY - 2007/9
Y1 - 2007/9
N2 - The application of intensity-modulated radiation therapy (IMRT) has enabled the delivery of high doses to the target volume while sparing the surrounding normal tissues. The drawbacks of intensity modulation, as implemented using a computer-controlled multileaf collimator (MLC), are the larger number of monitor units (MUs) and longer beam-on time as compared with conventional radiotherapy. Additionally, IMRT uses more beam directions - typically 5-9 for prostate treatment - to achieve highly conformal dose and normal-tissue sparing. In the present work, we study radiation-induced cancer risks attributable to IMRT delivery using MLC for prostate patients. Whole-body computed tomography scans were used in our study to calculate (according to report no. 116 from the National Council on Radiation Protection and Measurements) the effective dose equivalent received by individual organs. We used EGS4 and MCSIM to compute the dose for IMRT and three-dimensional conformal radiotherapy. The effects of collimator rotation, distance from the treatment field, and scatter and leakage contribution to the Whole-body dose were investigated. We calculated the whole-body dose equivalent to estimate the increase in the risk of secondary malignancies. Our results showed an overall doubling in the risk of secondary malignancies from the application of IMRT as compared with conventional radiotherapy. This increase in the risk of secondary malignancies is not necessarily related to a relative increase in MUs. The whole-body dose equivalent was also affected by collimator rotation, field size, and the energy of the photon beam. Smaller field sizes of low-energy photon beams (that is, 6 MV) with the MLC axis along the lateral axis of the patient resulted in the lowest whole-body dose. Our results can be used to evaluate the risk of secondary malignancies for prostate IMRT patients.
AB - The application of intensity-modulated radiation therapy (IMRT) has enabled the delivery of high doses to the target volume while sparing the surrounding normal tissues. The drawbacks of intensity modulation, as implemented using a computer-controlled multileaf collimator (MLC), are the larger number of monitor units (MUs) and longer beam-on time as compared with conventional radiotherapy. Additionally, IMRT uses more beam directions - typically 5-9 for prostate treatment - to achieve highly conformal dose and normal-tissue sparing. In the present work, we study radiation-induced cancer risks attributable to IMRT delivery using MLC for prostate patients. Whole-body computed tomography scans were used in our study to calculate (according to report no. 116 from the National Council on Radiation Protection and Measurements) the effective dose equivalent received by individual organs. We used EGS4 and MCSIM to compute the dose for IMRT and three-dimensional conformal radiotherapy. The effects of collimator rotation, distance from the treatment field, and scatter and leakage contribution to the Whole-body dose were investigated. We calculated the whole-body dose equivalent to estimate the increase in the risk of secondary malignancies. Our results showed an overall doubling in the risk of secondary malignancies from the application of IMRT as compared with conventional radiotherapy. This increase in the risk of secondary malignancies is not necessarily related to a relative increase in MUs. The whole-body dose equivalent was also affected by collimator rotation, field size, and the energy of the photon beam. Smaller field sizes of low-energy photon beams (that is, 6 MV) with the MLC axis along the lateral axis of the patient resulted in the lowest whole-body dose. Our results can be used to evaluate the risk of secondary malignancies for prostate IMRT patients.
KW - IMRT
KW - Prostate radiation therapy
KW - Secondary malignancies
UR - http://www.scopus.com/inward/record.url?scp=38049175059&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=38049175059&partnerID=8YFLogxK
M3 - Article
C2 - 18449157
AN - SCOPUS:38049175059
VL - 8
SP - 14
EP - 27
JO - Journal of Applied Clinical Medical Physics
JF - Journal of Applied Clinical Medical Physics
SN - 1526-9914
IS - 4
ER -