SU-GG-T-602: Cobalt-60 Based 3-D Conformal Radiotherapy Using an MLC and Corvus Treatment Planning System

2010 ◽  
Vol 37 (6Part25) ◽  
pp. 3326-3326
Author(s):  
L Xu ◽  
M Romesberg ◽  
S Bhat
Keyword(s):  
Treatment Planning ◽  
Conformal Radiotherapy ◽  
Planning System ◽  
Treatment Planning System

scholarly journals Independent verification of treatment planning system calculations

Nukleonika ◽  
2021 ◽  
Vol 66 (2) ◽  
pp. 47-53
Author(s):  
Edyta Dąbrowska-Szewczyk ◽  
Anna Zawadzka ◽  
Beata Brzozowska ◽  
Agnieszka Walewska ◽  
Paweł Kukołowicz
Keyword(s):  
Treatment Planning ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Rank Test ◽  
Average Dose ◽  
Independent Verification ◽  
The Mean

Abstract Purpose According to the available international recommendations, at least one independent verification of the calculations of number of monitor unit (MU) is required for every patient treated by teleradiotherapy. The aim of this study was to estimate the differences of dose distributions calculated with two treatment planning systems: Eclipse (Varian) and Oncentra MasterPlan (Elekta). Materials and methods The analysis was performed for 280 three-dimensional conformal radiotherapy treatment (3D-CRT) plans with photon beams from Varian accelerators: CL 600C/D X6 MV (109 plans), CL 2300C/D X6 MV (43 plans), and CL 2300C/D X15 MV (128 plans). The mean doses in the planning target volume (PTV) and doses at the isocenter point obtained with Eclipse and Oncentra MasterPlan (OMP) were compared with Wilcoxon matched-pairs signed rank test. Additionally, the treatment planning system (TPS) calculations were compared with dosimetric measurements performed in the inhomogeneous phantom. Results Data were analysed for 6 MV plans and for 15 MV plans separately, independently of the treatment machine. The dose values calculated in Eclipse were significantly (p <0.001) higher compared to calculations of OMP system. The average difference of the mean dose to PTV was (1.4 ± 1.0)% for X6 MV and (2.5 ± 0.6)% for X15 MV. Average dose disparities at the isocenter point were (1.3 ± 1.9)% and (2.1 ± 1.0)% for X6 MV and X15 MV beams, respectively. The largest differences were observed in lungs, air cavities, and bone structures. Moreover the variation in dosimetric measurements was less as compared to Eclipse calculations. Conclusions OMP calculations were introduced as the independent MU verification tool with the first action level range equal to 3.5%.

scholarly journals The choice of optimal radiotherapy technique for locally advanced maxillary carcinoma using 3d treatment planning system

2004 ◽  
Vol 61 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Dusan Mileusnic
Keyword(s):  
Maxillary Sinus ◽  
Treatment Planning ◽  
Locally Advanced ◽  
Three Dimensional ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Parotid Glands ◽  
3D Conformal Radiotherapy

Aim. To compare the isodose distribution of three radiotherapy techniques for locally advanced maxillary sinus carcinoma and analyze the potential of three-dimensional (3D) conformal radiotherapy planning in order to determine the optimal technique for target dose delivery, and spare uninvolved healthy tissue structures. Methods. Computed tomography (CT) scans of fourteen patients with T3-T4, N0, M0 maxillary sinus carcinoma were acquired and transferred to 3D treatment planning system (3D-TPS). The target volume and uninvolved dose limiting structures were contoured on axial CT slices throughout the volume of interest combining three variants of treatment plans (techniques) for each patient: 1. A conventional two-dimensional (2D) treatment plan with classically shaped one anterior two lateral opposite fields and two types of 3D conformal radiotherapy plans were compared for each patient. 2. Three-dimensional standard (3D-S) plan one anterior + two lateral opposite coplanar fields, which outlines were shaped with multileaf collimator (MLC) according to geometric information based on 3D reconstruction of target volume and organs at risk as seen in the beam eye's view (BEV) projection. 3. Three-dimensional non-standard (3D-NS) plan: one anterior + two lateral noncoplanar fields, which outlines were shaped in the same manner as in 3D-S plans. The planning parameters for target volumes and the degree of neurooptic structures and parotid glands protection were evaluated for all three techniques. Comparison of plans and treatment techniques was assessed by isodose distribution, dose statistics and dose-volume histograms. Results. The most enhanced conformity of the dose delivered to the target volume was achieved with 3D-NS technique, and significant differences were found comparing 3D-NS vs. 2D (Dmax: p<0,05 Daver: p<0,01; Dmin: p<0,05; V90: p<0,05, and V95: p<0,01), as well as 3D-NS vs. 3D-S technique (Dmin: p<0,05; V90: p<0,05, and V95: p<0,01), while there were no differences between 2D vs. 3D-S technique. 3D-S conformal plans were significantly superior to 2D plans regarding the protection of parotid glands, and the additional improvement of dose conformity was achieved with 3D-NS technique. 3D-NS technique resulted in the decrease of Dmax for ipsilateral retina compared with 3D-S technique, while the level of Dmax for optic nerve was increased (within an acceptable range) with 3D-NS technique. Conclusion. In this study, 3D planning of radiotherapy for locally advanced maxillary sinus carcinoma with noncoplanar fields, which number did not exceed the number of fields for conventional arrangement enabled conformal delivering of the adequate dose to the target volume with the improved sparing of adjacent uninvolved healthy tissue structures.

DOSIMETRIC COMPARISON OF VMAT AND 3D CONFORMAL RADIOTHERAPY IN PREOPERATIVE RECTAL CANCER

2021 ◽  
Author(s):  
Tatjana Miladinović ◽  
◽  
Aleksandar Miladinović ◽  
Nina Pavlović ◽  
Dragoslav Nikezić ◽  
...  
Keyword(s):  
Femoral Head ◽  
Treatment Planning ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Rectum Cancer ◽  
Clockwise Direction ◽  
3D Crt

The standard procedure in treating rectum cancer is surgical intervention, but presurgical chemotherapy and radiotherapy lead to a lower rate of localized recidives. Our study compared the results obtained by two techniques of radiation treatment planning (RTP) in radiotherapy, which patients received in the preoperative course of rectum cancer treatment, Volumetric Modulated Arc Therapy (VMAT) and field-in-field three-dimensional conformal radiotherapy (FIF 3D-CRT). We analyzed better coverage of the planning target volume (PTV) and better protection of organs from risk (OAR): bladder, bowel, left femoral head, and right femoral head results and monitor unit (MU). Also, we analyzed the target volume coverage indicators included homogeneity index (HI), and conformity index (CI). Selected five patients were treated in University Clinical Center Kragujevac during 2020. The two types of techniques for making radiotherapy plans, mentioned above, were designed for each patient using the same CT scans. All plans were done on the treatment planning system ECLIPSE- Version 15.6 (Varian). The prescribed dose for all patients was 50 Gy in 25 fractions. The first arc was planned in the clockwise direction and the second in the counter clockwise direction. FIF 3D-CRT plans were obtained by using fields from four different directions with the same isocenter. It was obtained that VMAT plans, compared to the FIF 3D-CRT, achieved better coverage of the PTV (D95%), better heterogeneity, and conformity. Protection for OAR such as the bladder, femoral heads, and small bowel is much better than that given by FIF 3D-CRT plans. However, the number of MU calculated by FIF 3D-CRT is almost twice lower compared to VMAT.

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