Nuruddin Nasution
Unknown Affiliation

Published : 3 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search

Point dose measurement on center and peripheral target for stereotactic treatment using Helical Tomotherapy Hi-Art Laras Ati Nur Fatimah; Nuruddin Nasution; Wahyu Edy Wibowo; Supriyanto Ardjo Pawiro
Journal of Medical Physics and Biophysics Vol 5, No 1 (2018)
Publisher : Indonesian Association of Physicists in Medicine (AIPM/AFISMI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (530.313 KB)

Abstract

Stereotactic radiosurgery (SRS) and stereotactic radiotherapy (SRT) using tomotherapy were advanced radiotherapy technique with prescribing high dose on the peripheral target to get as steep as possible fall-off dose criteria on the target. These technique need an accurate and high precision treatment delivery also passing the criteria for patient specific quality assurance. Point dose measurement was a simple verification to ensure these goals. However, there are many issues for point dose measurement with ionisation chamber related to the problem of high dose gradient area on the peripheral target. Therefore, the purpose of this study was to verify the assessment criteria of ±3% discrepancies for center and peripheral target measurement. The work has been done by point dose verification for 11 patient with brain cancer using Helical Tomotherapy Hi-Art. Point dose measurement were done on the center and peripheral PTV, also brainstem for organ parameter in the off-axis area, using Exradin A1SL. The measurement results show that highest discrepancy compared to the dose plan for center and peripheral target reach 1.95% and 2.81%, respectively. The Higher discrepancies shows for peripheral target compared to the center target measurement. The measurement on the brainstem show a highest discrepancies reach 5.29%. This result occur because of the off-axis area of the brainstem location. In conclusion, the center and peripheral target measurement are meet the criteria ±3% by the dose plan with peripheral target measurement shows higher discrepancies influences by volume averaging effect and lack of particle equilibrium of the condition related to the chamber size.
Lateral setup error analysis of dosimetric impact for nasopharynx carcinoma using intensity modulated radiotherapy treatment Syarifatul Ulya; Nuruddin Nasution; Wahyu Edy Wibowo; Supriyanto Ardjo Pawiro
Journal of Medical Physics and Biophysics Vol 5, No 1 (2018)
Publisher : Indonesian Association of Physicists in Medicine (AIPM/AFISMI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (596.253 KB)

Abstract

Patients with nasopharyngeal carcinoma have been analyzed for lateral setup error. Systematic and randomized inter-fractional setup errors were evaluated in 48 patients with this case. Based on these errors, the margin was drawn from CTV to obtain the delineation of PTV structure, called PTV margin. MVCT system in tomotherapy has been used to get the number of error with four-degree direction setup. Moreover, the biggest error direction value was evaluated with in 6 patients and analyzed at D98 in each PTV and OARs. The result of PTV margin for the lateral, longitudinal, vertical, and rotation was 4.91 mm, 4.27 mm, 3.37 mm and 3.53 mm, respectively. According to the result of the PTV margin, a lateral direction showed the biggest value of error. So, achievable dose coverage of PTVs on the effect of the lateral shift were 87.04%, 60.19%, and 50% for 2, 4 and 6 mm, respectively. Furthermore, OAR dose in the right position is increasing with larger shift setup direction.
The lateral shift effect of gamma index evaluation on tomotherapy Yosi Sudarsi Asril; Nuruddin Nasution; Wahyu Edy Wibowo; Supriyanto Ardjo Pawiro
Journal of Medical Physics and Biophysics Vol 5, No 1 (2018)
Publisher : Indonesian Association of Physicists in Medicine (AIPM/AFISMI)

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (592.99 KB)

Abstract

Fourteen patients with different cases have been planned and treated using helical Tomotherapy HI-ART system. To investigate the lateral shift effect on gamma index, the planning verification was evaluated for a point dose and a fluence dose measurement using ion chamber and Gafchromic EBT3 film, respectively. As a result, the difference between a measured and calculated point dose was under 3% for all interest organs, which account for 1.46±0.71% (parotid), 1.97±0.56% (pelvis and abdomen), 2.27±0.24% (brain), 1.56±0.51% (nasopharynx), and 1.43±1.3% (breast). In addition, Gamma index criteria used to evaluate fluence dose was 3mm (distance-to-agreement) and 3% (dose-difference) with 90% passed rate. Overall, the results, found in this study, shows that a lateral shift of the patient table resulted in an error beyond an acceptable tolerance if the table was shifted at more than 3mm. Gamma index criteria, then, is met if the lateral shift was within 3mm.