New - fast track review!
Dear Authors,
If you believe that your paper was mistakenly rejected by other leading journals and you do not agree with final decision, the editors of Reports of Practical Oncology and Radiotherapy offer new fast track review. You may submit your manuscript to Reports of Practical Oncology and Radiotherapy together with all prior peer-reviews obtained from the other journal and your rebuttal letter. We guarantee review based decision within 72 hours from the time we will receive your manuscript.

Fast track submission process: Please submit the manuscript with all reviews and rebuttal letter by email to Dr. Michal Masternak ( for fast review processing. To assure immediate attention the email title must to include: RPOR-fast track- Last Name First Name (of corresponding author).

Volume 15, Number 1, 2010

EPID in vivo dosimetry in RapidArc technique

Krzysztof Slosarek, Marta Szlag, Barbara Bekman, Aleksandra Grzadziel


Aim: The aim of the study was to estimate the dose at the reference point applying an
aSi-EPID device in the course of patient treatment.
Materials and methods: The method assumes direct proportionality between EPID signal and
dose delivered to the patient reference point during the treatment session. The procedure
consists of treatment plan calculation for the actual patient in the arc technique. The plan
was realized with an elliptic water-equivalent phantom. An ionization chamber inside the
phantom measured the dose delivered to the reference point. Simultaneously, the EPID
matrix measured the CU distribution. EPID signal was also registered during patient irradiation
with the same treatment plan. The formula for in vivo dose calculation was based
on the CU(g) function, EPID signal registered during therapy and the relation between the
dose and EPID signal level measured for the phantom. In vivo dose was compared with dose
planned with the treatment planning system.
Irradiation was performed with a Clinac accelerator by Varian Medical Systems in the
RapidArc technique. The Clinac was equipped with an EPID matrix (electronic portal image
device) of aSi-1000. Treatment plans were calculated with the Eclipse/Helios system. The
phantom was a Scanditronix/Wellhöfer Slab phantom, and the ionization chamber was a
0.6ccm PTW chamber.
Results: In vivo dose calculations were performed for five patients. Planned dose at the
reference point was 2 Gy for each treatment plan. Mean in vivo dose was in the range of
Conclusions: Our method was shown to be appropriate for in vivo dose evaluation in the
RapidArc technique.

Signature: Rep Pract Oncol Radiother, 2010; 15(1) : 8-14

« back