scholarly journals Stereotactic Body Radiotherapy for Small Lung Tumors in the University of Tokyo Hospital

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Hideomi Yamashita ◽  
Wataru Takahashi ◽  
Akihiro Haga ◽  
Satoshi Kida ◽  
Naoya Saotome ◽  
...  
Keyword(s):  
Treatment Time ◽  
Volumetric Modulated Arc Therapy ◽  
Dose Calculation ◽  
Target Volume ◽  
Lung Tumors ◽  
Local Control Rate ◽  
Internal Target Volume ◽  
Eligibility Criteria ◽  
Flattening Filter Free ◽  
Heterogeneity Correction

Our work on stereotactic body radiation therapy (SBRT) for primary and metastatic lung tumors will be described. The eligibility criteria for SBRT, our previous SBRT method, the definition of target volume, heterogeneity correction, the position adjustment using four-dimensional cone-beam computed tomography (4D CBCT) immediately before SBRT, volumetric modulated arc therapy (VMAT) method for SBRT, verifying of tumor position within internal target volume (ITV) using in-treatment 4D-CBCT during VMAT-SBRT, shortening of treatment time using flattening-filter-free (FFF) techniques, delivery of 4D dose calculation for lung-VMAT patients using in-treatment CBCT and LINAC log data with agility multileaf collimator, and SBRT method for centrally located lung tumors in our institution will be shown. In our institution, these efforts have been made with the goal of raising the local control rate and decreasing adverse effects after SBRT.

scholarly journals Investigation of 4D dose in volumetric modulated arc therapy-based stereotactic body radiation therapy: does fractional dose or number of arcs matter?

2020 ◽  
Vol 61 (2) ◽  
pp. 325-334
Author(s):  
Takashi Shintani ◽  
Mitsuhiro Nakamura ◽  
Yukinori Matsuo ◽  
Yuki Miyabe ◽  
Nobutaka Mukumoto ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Stereotactic Body Radiation Therapy ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Lung Tumors ◽  
Internal Target ◽  
Internal Target Volume ◽  
Stereotactic Body Radiation ◽  
Arc Therapy ◽  
Fractional Dose

Abstract The aim of this study was to assess the impact of fractional dose and the number of arcs on interplay effects when volumetric modulated arc therapy (VMAT) is used to treat lung tumors with large respiratory motions. A three (fractional dose of 4, 7.5 or 12.5 Gy) by two (number of arcs, one or two) VMAT plan was created for 10 lung cancer cases. The median 3D tumor motion was 17.9 mm (range: 8.2–27.2 mm). Ten phase-specific subplans were generated by calculating the dose on each respiratory phase computed tomography (CT) scan using temporally assigned VMAT arcs. We performed temporal assignment of VMAT arcs using respiratory information obtained from infrared markers placed on the abdomens of the patients during CT simulations. Each phase-specific dose distribution was deformed onto exhale phase CT scans using contour-based deformable image registration, and a 4D plan was created by dose accumulation. The gross tumor volume dose of each 4D plan (4D GTV dose) was compared with the internal target volume dose of the original plan (3D ITV dose). The near-minimum 4D GTV dose (D99%) was higher than the near-minimum 3D internal target volume (ITV) dose, whereas the near-maximum 4D GTV dose (D1%) was lower than the near-maximum 3D ITV dose. However, the difference was negligible, and thus the 4D GTV dose corresponded well with the 3D ITV dose, regardless of the fractional dose and number of arcs. Therefore, interplay effects were negligible in VMAT-based stereotactic body radiation therapy for lung tumors with large respiratory motions.

Preclinical studies for implementing flattening filter-free beams in hypofractionated volumetric-modulated arc therapy (VMAT) for prostate cancer radiotherapy

2017 ◽  
Vol 16 (3) ◽  
pp. 286-302
Author(s):  
Baochang Liu ◽  
Johnson Darko ◽  
Ernest Osei
Keyword(s):  
Prostate Cancer ◽  
Treatment Time ◽  
Volumetric Modulated Arc Therapy ◽  
Threshold Value ◽  
Dose Delivery ◽  
Cancer Radiotherapy ◽  
Dose Volume Histograms ◽  
Flattening Filter Free ◽  
Flattening Filter ◽  
Prostate Cancer Radiotherapy

AbstractBackgroundVolumetric-modulated arc therapy (VMAT) has emerged as one of the most favourable techniques for radiotherapy treatment in recent years because of its conformal dose distribution to the planning target volume (PTV), lower doses to adjacent normal organs at risk (OARs) and faster and easier dose delivery. A typical conventional VMAT protocol for low-intermediate risk prostate cancer uses a flattened 6 MV photon beam to deliver 78 Gy in 39 fractions, however, a recent Radiation Therapy Oncology Group study investigated prostate cancer radiotherapy with a hypofractionated dose scheme of 36·25 Gy in 5 fractions. One advantage of flattening filter-free (FFF) beams in radiotherapy is the higher doses in the central region on the dose profile and much higher dose delivery rates.Methods and materialsThis paper reports the investigation of preclinical studies for implementing FFF beams in hypofractionated VMAT for prostate cancer radiotherapy. All treatment planning were accomplished using Varian EclipseTM treatment planning system version 11 and delivered on Varian Truebeam linear accelerators. The studies compared the biological-effective dose–volume histograms and dose–volume histograms of PTV and OARs for 20 patients using conventional and hypofractionated dose schemes. The study also evaluated the 6 and 10 MV FFF by comparing 6 and 10 MV VMAT plans with the FFF beams. The treatment time was investigated using plans with 6 MV beams and doses of 2, 4, 5, 6, 7·25 Gy/fraction and plans with 10 MV FFF with a dose of 7·25 Gy/fraction. We also investigated an angular monitor unit (MU) quantity (MU/deg) and its threshold value for RapidArcTM plans, beyond which FFF beams can be considered superior to flattened beams in terms of treatment time increased caused by higher dose per fraction.ResultsThe results show that the hypofractionated plans resulted in greater biological equivalent doses to PTV and lower doses to OARs. The 10 MV FFF plans have statistically lower mean doses to all the OARs, whereas PTV homogeneity index remains the same compared with other beam energies. The mean body integral dose for the 20 patients is 8·7% lower using 10 MV FFF compared with 6 MV FFF mainly because of the higher energy and less required MUs with the 10 MV FFF beam. The hypofractionated scheme with 10 MV FFF plan has the same treatment time as that of the 6 MV plan at 2 Gy/fraction, as the higher dose delivery rates at 10 MV FFF can compensate for the higher prescribed dose per fraction without the need of extra treatment time.ConclusionIn this study, we observed that the 10 MV FFF beam is better for hypofractionated prostate cancer VMAT plan delivery. The threshold value of MU/deg is found to be 2·083 MU/deg based on our machine configurations.

scholarly journals Feasibility study of volumetric modulated arc therapy with Halcyon™ linac for total body irradiation

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Takuya Uehara ◽  
Hajime Monzen ◽  
Mikoto Tamura ◽  
Masahiro Inada ◽  
Masakazu Otsuka ◽  
...  
Keyword(s):  
Total Body Irradiation ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Dose Calculation ◽  
Target Volume ◽  
The Body ◽  
Whole Body ◽  
Data Set ◽  
Arc Therapy ◽  
Total Body

Abstract Background The use of total body irradiation (TBI) with linac-based volumetric modulated arc therapy (VMAT) has been steadily increasing. Helical tomotherapy has been applied in TBI and total marrow irradiation to reduce the dose to critical organs, especially the lungs. However, the methodology of TBI with Halcyon™ linac remains unclear. This study aimed to evaluate whether VMAT with Halcyon™ linac can be clinically used for TBI. Methods VMAT planning with Halcyon™ linac was conducted using a whole-body computed tomography data set. The planning target volume (PTV) included the body cropped 3 mm from the source. A dose of 12 Gy in six fractions was prescribed for 50% of the PTV. The organs at risk (OARs) included the lens, lungs, kidneys, and testes. Results The PTV D98%, D95%, D50%, and D2% were 8.9 (74.2%), 10.1 (84.2%), 12.6 (105%), and 14.2 Gy (118%), respectively. The homogeneity index was 0.42. For OARs, the Dmean of the lungs, kidneys, lens, and testes were 9.6, 8.5, 8.9, and 4.4 Gy, respectively. The V12Gy of the lungs and kidneys were 4.5% and 0%, respectively. The Dmax of the testes was 5.8 Gy. Contouring took 1–2 h. Dose calculation and optimization was performed for 3–4 h. Quality assurance (QA) took 2–3 h. The treatment duration was 23 min. Conclusions A planning study of TBI with Halcyon™ to set up VMAT-TBI, dosimetric evaluation, and pretreatment QA, was established.

SU-E-J-78: Internal Target Volume Delineation for Lung Tumors in Patients Treated with Robotic Radiosurgery

2014 ◽  
Vol 41 (6Part7) ◽  
pp. 173-173
Author(s):  
M Descovich ◽  
D Pinnaduwage ◽  
N Kirby ◽  
A Gottschalk ◽  
S Yom ◽  
...  
Keyword(s):  
Target Volume ◽  
Lung Tumors ◽  
Internal Target ◽  
Internal Target Volume ◽  
Target Volume Delineation ◽  
Robotic Radiosurgery ◽  
Volume Delineation

scholarly journals Is IMRT or VMAT superior or inferior to 3D conformal therapy in the treatment of lung cancer? A brief literature review

2021 ◽  
pp. 1-5
Author(s):  
Kazi T. Afrin ◽  
Salahuddin Ahmad
Keyword(s):  
Lung Cancer ◽  
Literature Review ◽  
Treatment Time ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Patient Comfort ◽  
Tumour Control ◽  
Intrafraction Motion ◽  
Conformal Therapy ◽  
3D Crt

Abstract Aim: To identify treatment outcome, dose uniformity, treatment time, toxicity among 3D conformal therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated arc therapy (VMAT) for non-small-cell lung cancer (NSCLC) based on literature review. Methods: A literature search was conducted using PubMed/MEDLINE, BMC—part of Springer Nature, Google Scholar and iMEDPub Ltd with the following keywords for filtering: 3D-CRT, IMRT, VMAT, lung cancer, local control and radiobiology. A total of 14 publications were finally selected for the comparison of 3D-CRT, IMRT and VMAT to determine which technique is superior or inferior among these three. Results: Compared to 3D-CRT, IMRT delivers more precise treatment, has better conformal dose coverage to planning target volume (PTV) that covers gross tumour with microscopic extension, respiratory tumour motion and setup margin. 3D-CRT has large number of limitations: low overall survival (OS), large toxicity, secondary malignancies. Conclusions: It is difficult to choose the best technique for treating NSCLC due to patient conditions and technique availability. A high-precision treatment may improve tumour control probability (TCP) and patient’s quality of life. VMAT, whether superior or not, needs more clinical trials to treat NSCLC and requires longer dose optimisation time with the greatest benefit of rapid treatment delivery, improved patient comfort, reduced intrafraction motion and increased patient throughput compared to IMRT and 3D-CRT.

scholarly journals Effectiveness of robust optimization in volumetric modulated arc therapy using 6 and 10 MV flattening filter-free beam therapy planning for lung stereotactic body radiation therapy with a breath-hold technique

2020 ◽  
Vol 61 (4) ◽  
pp. 575-585
Author(s):  
Hideharu Miura ◽  
Shuichi Ozawa ◽  
Yoshiko Doi ◽  
Minoru Nakao ◽  
Katsumaro Kubo ◽  
...  
Keyword(s):  
Radiation Therapy ◽  
Robust Optimization ◽  
Stereotactic Body Radiation Therapy ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Breath Holding ◽  
X Ray ◽  
Flattening Filter Free ◽  
Arc Therapy ◽  
Flattening Filter

Abstract We investigated the feasibility of a robust optimization with 6 MV X-ray (6X) and 10 MV X-ray (10X) flattening filter-free (FFF) beams in a volumetric modulated arc therapy (VMAT) plan for lung stereotactic body radiation therapy (SBRT) using a breath-holding technique. Ten lung cancer patients were selected. Four VMAT plans were generated for each patient; namely, an optimized plan based on the planning target volume (PTV) margin and a second plan based on a robust optimization of the internal target volume (ITV) with setup uncertainties, each for the 6X- and 10X-FFF beams. Both optimized plans were normalized by the percentage of the prescription dose covering 95% of the target volume (D95%) to the PTV (1050 cGy × 4 fractions). All optimized plans were evaluated using perturbed doses by specifying user-defined shifted values from the isocentre. The average perturbed D99% doses to the ITV, compared to the nominal plan, decreased by 369.1 (6X-FFF) and 301.0 cGy (10X-FFF) for the PTV-based optimized plan, and 346.0 (6X-FFF) and 271.6 cGy (10X-FFF) for the robust optimized plan, respectively. The standard deviation of the D99% dose to the ITV were 163.6 (6X-FFF) and 158.9 cGy (10X-FFF) for the PTV-based plan, and 138.9 (6X-FFF) and 128.5 cGy (10X-FFF) for the robust optimized plan, respectively. Robust optimized plans with 10X-FFF beams is a feasible method to achieve dose certainty for the ITV for lung SBRT using a breath-holding technique.

Effect of paclitaxel-carboplatin (PC) consolidation chemotherapy after weekly PC concurrent chemo-radiotherapy (CCR) for patients with locally advanced non-small cell lung cancer (LA-NSCLC): 3-year definitive results of the B001-phase III GERCOR-study

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 7112-7112 ◽  
Author(s):  
P. Colin ◽  
N. Jovenin ◽  
G. Ganem ◽  
J. Duhamel ◽  
J. Oster ◽  
...  
Keyword(s):  
Febrile Neutropenia ◽  
Locally Advanced ◽  
Target Volume ◽  
Local Control Rate ◽  
Phase Iii ◽  
Rank Test ◽  
Eligibility Criteria ◽  
Additional Chemotherapy ◽  
Sequential Schedule

7112 Background: Local control rate of LA-NSCLC seems better after concurrent CCR than after sequential schedule; the role of additional chemotherapy is not clearly defined. A multi-institutional phase-III trial was conducted to evaluate the role of chemotherapy consolidation after CCR Methods: Eligibility criteria included mediastinoscopy-controlled unresectable NSCLC stage IIIA (27%) - IIIB (59%) and inoperable mediastinal recurrence after surgery (14%), PS < 3, clinical target volume compatible with a minimal 60 Gy dose radiation. After registration, patients (pts) were treated with combination of weekly P (45 mg/m2), C (AUC 2), and radiotherapy 60–66 Gy (5 × 2 Gy per week). The pts with response or stable disease were randomized either to receive 3 cycles of P (175 mg/m2) and C (AUC 5) consolidation on days 1–22–43 or observation. Primary endpoint was OS (log-rank test), planned sample was 122 pts. Results: Actually, 71 pts were enrolled. Thirty pts (42%) were not randomized because of progression (22%) and disease-related death (22%), toxicity (26%), refusal (9%), protocol violation (21%). Toxicity grade 3–4 per patient: for the PC-TRT sequence; neutropenia 5%, febrile neutropenia 5%, thrombopenia 5%, pneumonitis 5%, oesophagitis 19%. For the PC consolidation sequence; neutropenia 24%, febrile neutropenia 6%, thrombopenia 0% (no treatment-related death). After a minimal follow-up of 3 years, despite poor inclusion rate, OS and PFS were greater in the PC consolidation group with 3-year OS: 29.9% vs 10% (HR = 0.45; CI 0.95: 0.22–0.91) (p = 0.002) and 3-year PFS: 27.8% vs 10% (HR = 0.6; CI 0.95: 0.3–1.3) (p = 0.17). Nine pts developed metastasis in each treatment arm. Conclusions: The addition of PC consolidation to PC-CCR is not easily feasible for all LA-NSCLC. For selected pts (only 58% of pts in this trial), despite premature ending of the trial because of slow accrual, PC consolidation significantly improved the 3-year OS and probably PFS. Because no difference in the metastatic incidence was observed, the effect of chemotherapy dosage in the consolidation arm could be explained by delaying metastasis. No significant financial relationships to disclose.

scholarly journals VMAT Optimization and Dose Calculation in the Presence of Metallic Hip Prostheses

2019 ◽  
Vol 18 ◽  
pp. 153303381989225 ◽  
Author(s):  
Holly M. Parenica ◽  
Panayiotis Mavroidis ◽  
William Jones ◽  
Gregory Swanson ◽  
Niko Papanikolaou ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Planning Target Volume ◽  
Volumetric Modulated Arc Therapy ◽  
Dose Calculation ◽  
Target Volume ◽  
Calculation Algorithm ◽  
Hip Prostheses ◽  
Ion Chamber ◽  
Arc Therapy ◽  
Monte Carlo Dose Calculation

Introduction: This research quantifies and compares the effect of hip prostheses on dose distributions calculated using collapsed cone convolution superposition and Monte Carlo (with and without correcting for the density of the implant and surrounding tissues). The use of full volumetric modulated arc therapy arcs versus volumetric modulated arc therapy arcs avoiding the hip implants (skip arcs) was also studied. Materials and Methods: Six prostate patients with hip prostheses were included in this study. The hip prostheses and the streaking artifacts on the computed tomography images were contoured by a single physician, and full volumetric modulated arc therapy arcs were created in the Pinnacle3 TPS. Copies of each plan were made, and the doses were recalculated with the densities of the prostheses and surrounding tissues overridden. The plans were then exported to Monaco and recalculated using a Monte Carlo dose calculation algorithm, with and without densities of the prosthesis and surrounding tissues overridden. Results: With density overrides, Pinnacle3 had a 4.4% error for ion chamber measurements. Monaco was within 0.2% of ion chamber measurement when density overrides were used. On average, when density overrides were used in Pinnacle3 for patient dose calculations, the planning target volume D95 value dropped from 99.3% to 82.7%. Monaco also showed decreased planning target volume coverage when plans were recalculated with correct density information. Full arc plans (with density overrides) for the patient with a bilateral prosthesis provided significant bladder sparing and some rectal sparing compared to skip arc plans. Conclusion: When planning for prostate patients with hip prostheses, correct density information for implants and surrounding tissues should be used to optimize the plan and ensure optimal accuracy. If available, a Monte Carlo algorithm should be used as a second check. Full arcs could be used to spare dose to organs at risk, while maintaining adequate planning target volume coverage, when using a Monte Carlo dose calculation algorithm.

scholarly journals Novel strategy with the automatic non-coplanar volumetric-modulated arc therapy for angiosarcoma of the scalp.

2020 ◽  
Author(s):  
Shoki Inui ◽  
Yoshihiro Ueda ◽  
Shingo Ohira ◽  
Haruhi Tsuru ◽  
Masaru Isono ◽  
...  
Keyword(s):  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Normal Brain ◽  
Pass Rates ◽  
Flattening Filter Free ◽  
Arc Therapy ◽  
Dosimetric Accuracy ◽  
Flattening Filter ◽  
Novel Strategy

Abstract Background Total scalp irradiation presents technical and dosimetric challenges. While reports suggest that HyperArc, a new stereotactic radiosurgery planning technique, is associated with high conformity and rapid dose fall-off, the performance of HyperArc plans for cancers of the head and neck regions has not been explored. The current study aimed to compare the dosimetric performance of HyperArc plans with those of non-coplanar volumetric-modulated arc therapy (VMAT) plans in angiosarcoma of the scalp.Methods Six patients with angiosarcoma of the scalp were included in this study. Performance of three different non-coplanar plans administered using TrueBeam Edge was compared. Three plans were employed namely VMAT using flattening filter (FF) beams (VMAT-FF), HyperArc using FF beams (HyperArc-FF), and HyperArc using flattening filter free (FFF) beams (HyperArc-FFF). The dose distribution, dosimetric parameters, and dosimetric accuracy for all plans were evaluated.Results The three plans showed no statistically significant differences in target volume coverage, conformity, and homogeneity. With regard to the normal brain tissue, the received volume doses were significantly lower for the HyperArc-FF and the HyperArc-FFF plans than for the VMAT-FF plans. Mean brain doses were 17.56 ± 5.70 Gy, 12.88 ± 3.36 Gy, and 13.24 ± 3.55 Gy in the VMAT-FF, the HyperArc-FF, and the HyperArc-FFF plans, respectively. There were almost no differences in sparing the organs at risk between the HyperArc-FF and HyperArc-FFF plans. The HyperArc-FF and HyperArc-FFF plans provide a shorter beam-on time than does the VMAT-FF plan. The 3%/2 mm gamma test pass rates were above 95% for all plans.Conclusions Our results suggested that the HyperArc plan can be potentially used for radiation therapy of target regions with large and complicated shape, such as the scalp, and that there are no advantages of using FFF beams.

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