scholarly journals Adequate target volume in total-body irradiation by intensity-modulated radiation therapy using helical tomotherapy: a simulation study

2016 ◽  
Vol 58 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Ryosuke Takenaka ◽  
Akihiro Haga ◽  
Hideomi Yamashita ◽  
Keiichi Nakagawa
Keyword(s):  
Radiation Therapy ◽  
Total Body Irradiation ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
The Body ◽  
High Fluence ◽  
Intensity Modulated ◽  
Small Set ◽  
Total Body ◽  
Set Up

Abstract Recently, intensity-modulated radiation therapy (IMRT) has been used for total-body irradiation (TBI). Since the planning target volume (PTV) for TBI includes the surrounding air, a dose prescription to the PTV provides high fluence to the body surface. Thus with just a small set-up error, the body might be exposed to a high-fluence beam. This study aims to assess which target volume should be prescribed the dose, such as a clinical target volume (CTV) with a margin, or a CTV that excludes the surface area of the skin. Three treatment plans were created for each patient: the 5-mm clipped plan (Plan A), the 0-mm margin plan (Plan B) and the 5-mm margin plan (Plan C). The CTV was the whole body. PTVs were the CTV with the exception of 5 mm from the skin surface in Plan A, equal to the CTV in Plan B, and the CTV with a 5 mm margin in Plan C. The prescribed dose was 12 Gy in six fractions. To assess the influence of the set-up error, dose distributions were simulated on computed tomography (CT) images shifted 2 pixels (= 4.296 mm), 5 pixels (= 10.74 mm) and 10 pixels (= 21.48 mm) in the lateral direction from the original CT. With a set-up error of 10.74 mm, V110% was 8.8%, 11.1% and 23.3% in Plans A, B and C, respectively. The prescription to the PTV containing the surrounding air can be paradoxically vulnerable to a high-dose as a consequence of a small set-up error.

A planning study to optimise a simultaneously integrated boost treatment of larynx cancer with seven intensity-modulated radiation therapy (IMRT) beams

2018 ◽  
Vol 17 (4) ◽  
pp. 447-454 ◽  
Author(s):  
M. Erraoudi ◽  
M. A. Youssoufi ◽  
F. Bentayeb ◽  
M. R. Malisan
Keyword(s):  
Radiation Therapy ◽  
Organs At Risk ◽  
Intensity Modulated Radiation Therapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
The Body ◽  
Larynx Cancer ◽  
Body Volume ◽  
Intensity Modulated ◽  
Integrated Boost

AbstractBackgroundIntensity-modulated radiation therapy (IMRT) is one of the most reported techniques for head and neck cancer treatment, as it allows a good coverage of the planning target volume (PTV) while sparing the surrounding organs at risk (OAR) better than conventional conformal radiotherapy. The objective of this work is to optimise an IMRT technique for the simultaneously integrated boost (SIB) treatment of larynx cancer delivering a total dose of 69·96 Gy to the boost volume and 54·45 Gy to the elective volume in 33 fractions.MethodsThree IMRT techniques, each using seven equally spaced beams, were planned for a sample of 10 patients. The first two techniques (IMRT-0 and IMRT-26) differ only for the starting angle of the seven beams, whereas the third (IMRT-CT) combines both these techniques by delivering IMRT-0 in the first half of treatment, and IMRT-26 in the second half, thus taking advantage of using 14 beams in total while using seven at a time only. The planning results were compared according to the dose coverage, homogeneity and conformity of the two PTVs, as well as to the dose to OARs, that is, spinal cord, parotids, mandible, brainstem and healthy tissue (defined as the body volume minus the sum of PTVs).ResultsBasically the PTV coverage resulted acceptable and comparable with all the three techniques. Concerning OARs, statistically better results are obtained in IMRT-CT when compared with IMRT-26 and IMRT-0.ConclusionThe IMRT-CT technique, combining two different seven-beam setups, delivered in two treatment phases, improves dose distribution without increasing delivery time.

scholarly journals Safety of total body irradiation using intensity-modulated radiation therapy by helical tomotherapy in allogeneic hematopoietic stem cell transplantation: a prospective pilot study

2020 ◽  
Vol 61 (6) ◽  
pp. 969-976
Author(s):  
Tatsuya Konishi ◽  
Hiroaki Ogawa ◽  
Yuho Najima ◽  
Shinpei Hashimoto ◽  
Atsushi Wada ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Stem Cell ◽  
Pilot Study ◽  
Hematopoietic Stem Cell Transplantation ◽  
Total Body Irradiation ◽  
Helical Tomotherapy ◽  
Intensity Modulated Radiation Therapy ◽  
Hematopoietic Stem ◽  
Intensity Modulated ◽  
Total Body

Abstract Total body irradiation using intensity-modulated radiation therapy total body irradiation (IMRT-TBI) by helical tomotherapy in allogeneic hematopoietic stem cell transplantation (allo-HSCT) allows for precise evaluation and adjustment of radiation dosage. We conducted a single-center pilot study to evaluate the safety of IMRT-TBI for allo-HSCT recipients. Patients with hematological malignancies in remission who were scheduled for allo-HSCT with TBI-based myeloablative conditioning were eligible. The primary endpoint was the incidence of adverse events (AEs). Secondary endpoints were engraftment rate, overall survival, relapse rate, non-relapse mortality, and the incidence of acute and chronic graft-versus-host disease (aGVHD and cGVHD, respectively). Between July 2018 and November 2018, ten patients were recruited with a median observation duration of 571 days after allo-HSCT (range, 496–614). D80% for planning target volume (PTV) in all patients was 12.01 Gy. Average D80% values for lungs, kidneys and lenses (right/left) were 7.50, 9.03 and 4.41/4.03 Gy, respectively. Any early AEs (within 100 days of allo-HSCT) were reported in all patients. Eight patients experienced oral mucositis and gastrointestinal symptoms. One patient experienced Bearman criteria grade 3 regimen-related toxicity (kidney and liver). All cases achieved neutrophil engraftment. There was no grade III–IV aGVHD or late AE. One patient died of sinusoidal obstruction syndrome 67 days after allo-HSCT. The remaining nine patients were alive and disease-free at final follow-up. Thus, IMRT-TBI was well tolerated in terms of early AEs in adult patients who underwent allo-HSCT; this warrants further study with longer observation times to monitor late AEs and efficacy.

SU-E-T-813: Using Intensity Modulated Radiation Therapy for Total Body Irradiation - a Phantom Study

2011 ◽  
Vol 38 (6Part23) ◽  
pp. 3678-3678 ◽  
Author(s):  
D Vade BonCoeur ◽  
C Pelloski ◽  
N Gupta ◽  
M Weldon ◽  
J Woollard ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Total Body Irradiation ◽  
Intensity Modulated Radiation Therapy ◽  
Phantom Study ◽  
Intensity Modulated ◽  
Total Body

scholarly journals Dosimetric comparison between 3D conformal and intensity-modulated radiation therapy for prostate cancer

2010 ◽  
Vol 9 (2) ◽  
pp. 77-85 ◽  
Author(s):  
Courtney Buckey ◽  
Gregory Swanson ◽  
Sotirios Stathakis ◽  
Nikos Papanikolaou
Keyword(s):  
Radiation Therapy ◽  
Organs At Risk ◽  
External Beam Radiotherapy ◽  
Radiation Therapy Oncology Group ◽  
Intensity Modulated Radiation Therapy ◽  
Standard Of Care ◽  
Target Volume ◽  
Conformal Radiation Therapy ◽  
Intensity Modulated ◽  
3D Crt

AbstractBackground and Purpose: Intensity-modulated radiation therapy (IMRT) is considered by many to be the standard of care in the delivery of external-beam radiotherapy treatments to the prostate. The purpose of this study is to assess the validity of the purported benefits of IMRT.Materials and Methods: Treatment plans were produced for 10 patients using both 3D conformal radiation therapy (3D-CRT) and IMRT, utilising the dose constraints recommended by the Radiation Therapy Oncology Group (RTOG) 0415 protocol. Three IMRT modalities used in this study were linear accelerator based IMRT, helical tomotherapy, and serial tomotherapy. The prescription to the target, 76 Gy, was the same for all plans.Results: In general the 3D-CRT plans satisfied the RTOG criteria for planning target volume (PTV) coverage, and met or bettered the dose criteria for the organs at risk. PTV coverage was more homogeneous for the IMRT plans than the 3D-CRT plans but not significantly improved.Conclusions: Technically, because the IMRT plans required greater effort for the optimisation, longer treatment times and higher monitor units, the use of IMRT for the fulfilment of the protocol’s dosimetric goals was not justified using these constraints.

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