Clinical implementation of intensity modulated radiotherapy: initial experiences

2003 ◽  
Vol 3 (2) ◽  
pp. 63-67 ◽  
Author(s):  
H. A. McNair ◽  
J. Selous-Hodges ◽  
D. Convery ◽  
V. Cosgrove ◽  
J. Balyckyi ◽  
...  
Keyword(s):  
Intensity Modulated Radiotherapy ◽  
Planning System ◽  
Clinical Implementation ◽  
Linear Accelerators ◽  
Dose Distributions ◽  
Intensity Modulated ◽  
The United Kingdom ◽  
Potential Clinical Benefit ◽  
Radiotherapy Department ◽  
New Treatment

The development of intensity modulated radiotherapy (IMRT) has allowed the delivery of concave dose distributions. Planning studies have demonstrated the potential clinical benefit of IMRT in the treatment of the prostate and pelvic nodes in patients with advanced prostate cancer. As a consequence, IMRT was clinically implemented in the Royal Marsden NHS Trust in September 2000, using Elekta Sli series linear accelerators and NOMOS Corvus v3.0 planning system. As a relatively new treatment procedure in the United Kingdom, the clinical implementation involved developing appropriate quality assurance and verification procedures as well as training staff. This paper describes the practicalities of implementing IMRT into the routine workload of the radiotherapy department.

scholarly journals Implementation of compensator-based intensity modulated radiotherapy with a conventional telecobalt machine using missing tissue approach

2018 ◽  
Vol 24 (4) ◽  
pp. 171-179
Author(s):  
Samuel N. A. Tagoe ◽  
Samuel Y. Mensah ◽  
John J. Fletcher
Keyword(s):  
Treatment Planning ◽  
Specific Treatment ◽  
Intensity Modulated Radiotherapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Dose Distributions ◽  
Intensity Modulated ◽  
Limit Value ◽  
Tissue Equivalent ◽  
Tissue Equivalent Phantom

Abstract Objectives: The present study aimed to generate intensity-modulated beams with compensators for a conventional telecobalt machine, based on dose distributions generated with a treatment planning system (TPS) performing forward planning, and cannot directly simulate a compensator. Materials and Methods: The following materials were selected for compensator construction: Brass, Copper and Perspex (PMMA). Boluses with varying thicknesses across the surface of a tissue-equivalent phantom were used to achieve beam intensity modulations during treatment planning with the TPS. Beam data measured for specific treatment parameters in a full scatter water phantom with a 0.125 cc cylindrical ionization chamber, with a particular compensator material in the path of beams from the telecobalt machine, and that without the compensator but the heights of water above the detector adjusted to get the same detector readings as before, were used to develop and propose a semi-empirical equation for converting a bolus thickness to compensator material thickness, such that any point within the phantom would receive the planned dose. Once the dimensions of a compensator had been determined, the compensator was constructed using the cubic pile method. The treatment plans generated with the TPS were replicated on the telecobalt machine with a bolus within each beam represented with its corresponding compensator mounted on the accessory holder of the telecobalt machine. Results: Dose distributions measured in the tissue-equivalent phantom with calibrated Gafchromic EBT2 films for compensators constructed based on the proposed approach, were comparable to those of the TPS with deviation less than or equal to ± 3% (mean of 2.29 ± 0.61%) of the measured doses, with resultant confidence limit value of 3.21. Conclusion: The use of the proposed approach for clinical application is recommended, and could facilitate the generation of intensity-modulated beams with limited resources using the missing tissue approach rendering encouraging results.

Assessing the Difference between Planned and Delivered Intensity-modulated Radiotherapy Dose Distributions based on Radiobiological Measures

2006 ◽  
Vol 18 (7) ◽  
pp. 529-538 ◽  
Author(s):  
P. Mavroidis ◽  
B.C. Ferreira ◽  
N. Papanikolaou ◽  
R. Svensson ◽  
C. Kappas ◽  
...  
Keyword(s):  
Intensity Modulated Radiotherapy ◽  
Dose Distributions ◽  
Intensity Modulated ◽  
The Difference ◽  
Radiotherapy Dose

scholarly journals Dosimetric evaluation of cobalt-60 teletherapy in advanced radiation oncology

2018 ◽  
Vol 18 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Manny Mathuthu ◽  
Nhlakanipho Wisdom Mdziniso ◽  
Yihunie Hibstie Asres
Keyword(s):  
Three Dimensional ◽  
Intensity Modulated Radiotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Planning System ◽  
Treatment Planning System ◽  
Solid State Drives ◽  
Water Phantom ◽  
Intensity Modulated ◽  
Gafchromic Ebt2 Film ◽  
Ebt2 Film

AbstractBackgroundRecent investigations demonstrate a strong potential for cobalt-60 (Co-60)-based teletherapy. The influence of the lower energy and penetration of a cobalt-60 beam compared with linear accelerator beams is negligible for intensity-modulated radiotherapy.PurposeThe aim of this research is to investigate source head fluence modulation in cobalt-60 teletherapy by using a three-dimensional (3D) physical compensator and secondary collimator jaw motion.Materials and methodsThe Oncentra treatment planning system was used to develop three hypothetical plans by secondary collimator jaw motion. A clinical MDS Nordion Equinox 80 cobalt-60 teletherapy unit was used to acquire conventional water phantom beam characteristics. Fluence modulation experiments were executed at 5·0 cm depth in a PTW universal intensity-modulated radiation therapy (IMRT) verification phantom using calibrated Gafchromic external beam therapy 2 (EBT2) and RTQA2-1010 film batches. Gafchromic EBT2 film was used to sample intensity maps generated by secondary collimator jaw motion, yet Gafchromic RTQA2-1010 film sampled maps from the 3D physical compensator. The solid-state drives used were 75·0 and 74·3 cm for the Gafchromic EBT2 and Gafchromic RTQA2-1010 film measurements.ResultsA 2D gamma index analysis was coded to compare EBT2 film measurements with Digital Imaging and Communications in Medicine data. This analysis was also used to verify film measurements versus Monte-Carlo simulations.ConclusionLateral beam profiles generated from water phantom measurements were used to establish source head fluence modulation on the film measurements. The source head fluence of a cobalt-60 teletherapy beam could be modulated by secondary collimator jaw motion and using a 3D physical compensator.

Improvement of tomographic intensity modulated radiotherapy dose distributions using periodic shifting of arc abutment regions

2000 ◽  
Vol 27 (7) ◽  
pp. 1610-1616 ◽  
Author(s):  
Leonid B. Leybovich ◽  
Nesrin Dogan ◽  
Anil Sethi ◽  
Matthew J. Krasin ◽  
Bahman Emami
Keyword(s):  
Intensity Modulated Radiotherapy ◽  
Dose Distributions ◽  
Intensity Modulated ◽  
Radiotherapy Dose

A dosimetric study of skin toxicity induced by 3-D conventional and intensity-modulated radiotherapy techniques using immobilization mask for treatment of head-and-neck (nasopharyngeal cancer) carcinoma: a prospective study

2018 ◽  
Vol 18 (02) ◽  
pp. 132-137
Author(s):  
Khaldoon Mahmoud Radaideh
Keyword(s):  
Nasopharyngeal Cancer ◽  
Intensity Modulated Radiotherapy ◽  
Skin Toxicity ◽  
Planning System ◽  
Treatment Planning System ◽  
Skin Dose ◽  
Average Percentage ◽  
Intensity Modulated ◽  
Acute Skin Toxicity ◽  
3D Crt

AbstractBackgroundThe purpose of this study was to investigate variations in surface dose, with and without the use of a Klarity® Mask (Orfit Industries America, Wijnegem, Belgium), using intensity-modulated radiotherapy (IMRT) and 3-D conventional radiotherapy (3D-CRT).Materials and methodsThermoluminescent dosimeters (TLDs) together with a phantom were used to examine acute skin toxicity during nasopharyngeal cancer treatment. These plans were sequentially delivered to the perspex phantom. Dosimeters were placed in five fixed regions over the skin. A Klarity mask for immobilization was used for covering the head, neck, and shoulder. The phantom was irradiated with and without a Klarity Mask, using IMRT and 3D-CRT, respectively.ResultsThe Klarity mask increased the skin doses for IMRT and 3D-CRT approximately 18·6% and 8·6%, respectively, from the prescribed maximum skin dose using treatment planning system (TPS). Additionally, the average percentage dose between IMRT and 3D-CRT received on the surface region was 30·9%, 24·9% with and without Klarity mask respectively. The average percentage dose received on surfaces from the total therapeutic dose 70 Gy, without using the mask was 7·7% and 5·7%, for IMRT and 3D-CRT, respectively. The TPS overestimated the skin dose for IMRT planning by 20%, and for 3D-CRT by 16·6%, compared with TLD measurements.ConclusionsThe results of this study revealed that IMRT significantly increases acute skin toxicity, compared with CRT. Although it is recommended to use Klarity mask as a sparing tool of normal tissue, it increases the risk of skin toxicity. In conclusion, skin dose is an important issue of focus during radiotherapy.

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