scholarly journals Volumetric Modulated Arc Therapy Craniospinal Re-Irradiation of Adulthood Medulloblastoma Leptomeningeal Disease

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Kremena Petrova ◽  
Lena Marinova ◽  
Zdravko Yankov ◽  
Dimka Nikolaeva
Keyword(s):  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Cauda Equina ◽  
Target Volume ◽  
Leptomeningeal Disease ◽  
Radiation Toxicity ◽  
Advantages And Disadvantages ◽  
Arc Therapy ◽  
Early Radiation ◽  
Clinical Cases

For the first time in the English medical literature we present two adulthood clinical cases with medulloblastoma leptomeningeal disease (LMD) in which we have performed second craniospinal irradiation (re-CSI) using bias volumetric-modulated arc therapy (VMAT) technique. In this article we present bias volumetric-modulated arc therapy (VMAT) technique for repeated CSI (re-CSI) in two patients with adulthood medulloblastoma leptomeningeal disease (LMD). In both clinical cases (case1/case2) with adulthood medulloblastoma LMD, re-CSI has been performed using the bias VMAT technique in the area of the spinal cord up to total dose (TD) - 24 Gy/32 Gy; cauda equina up to TD- 28 Gy/38 Gy; in the cerebellum up to TD- 24 Gy/28 Gy; both cerebral hemispheres up to TD- 26 Gy/32 Gy and the cerebral ventricles up to TD-30 Gy/38 Gy with daily dose (DD)-1.8 Gy (17/21fractions). We describe in detail the stages of dosimetry planning of this radiotherapy technique, presenting its advantages and disadvantages, the observed early radiation toxicity and the possible treatment outcome. Volumetric-modulated radiotherapy with bias dose VMAT technique in adulthood medulloblastoma patients achieves improved dose homogeneity at the junction of the fields, increased compliance with the target volume and minimized dose to the organs at risk (OARs).

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.

scholarly journals Dosimetric Comparison of Helical Tomotherapy, Volumetric-Modulated Arc Therapy, and Intensity-Modulated Proton Therapy for Angiosarcoma of the Scalp

2021 ◽  
Vol 20 ◽  
pp. 153303382098586
Author(s):  
Tomoki Mizuno ◽  
Natsuo Tomita ◽  
Taiki Takaoka ◽  
Masashi Tomida ◽  
Hiroshi Fukuma ◽  
...  
Keyword(s):  
Proton Therapy ◽  
Helical Tomotherapy ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
The Other ◽  
Intensity Modulated Proton Therapy ◽  
Intensity Modulated ◽  
Arc Therapy ◽  
Dose Constraint

Objective: We compared radiotherapy plans among helical tomotherapy (HT), volumetric-modulated arc therapy (VMAT), and intensity-modulated proton therapy (IMPT) for angiosarcoma of the scalp (AS). Methods: We conducted a planning study for 19 patients with AS. The clinical target volume (CTV) 1 and CTV2 were defined as the gross tumor volume with a specific margin and total scalp, respectively. For HT and VMAT, the planning target volume (PTV) 1 and PTV2 were defined as CTV1 and CTV2 with 0.5-cm margins, respectively. For IMPT, robust optimization was used instead of a CTV-PTV margin (i.e. CTV robust). The targets of the HT and VMAT plans were the PTV, whereas the IMPT plans targeted the CTV robust. In total, 70 Gy and 56 Gy were prescribed as the D95% (i.e. dose to 95% volume) of PTV1 (or CTV1 robust) and PTV2 (or CTV2 robust), respectively, using the simultaneous integrated boost (SIB) technique. Other constraint goals were also defined for the target and organs at risk (OAR). Results: All dose constraint parameters for the target and OAR met the goals within the acceptable ranges for the 3 techniques. The coverage of the targets replaced by D95% and D98% were almost equivalent among the 3 techniques. The homogeneity index of PTV1 or CTV1 robust was equivalent among the 3 techniques, whereas that of PTV2 or CTV2 robust was significantly higher in the IMPT plans than in the other plans. IMPT reduced the Dmean of the brain and hippocampus by 49% to 95%, and the Dmax of the spinal cord, brainstem, and optic pathway by 70% to 92% compared with the other techniques. Conclusion: The 3 techniques with SIB methods provided sufficient coverage and satisfactory homogeneity for the targets, but IMPT achieved the best OAR sparing.

Volumetric modulated arc therapy: a dosimetric comparison with dynamic IMRT and step-and-shoot IMRT

2019 ◽  
Vol 19 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Payal Raina ◽  
Sudha Singh ◽  
Rajanigandha Tudu ◽  
Rashmi Singh ◽  
Anup Kumar
Keyword(s):  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Intensity Modulated Radiation Therapy ◽  
Target Volume ◽  
Planning System ◽  
Treatment Planning System ◽  
Conformity Index ◽  
Delivery Time ◽  
Arc Therapy ◽  
Step And Shoot

AbstractAim:The aim of this study was to compare volumetric modulated arc therapy (VMAT) with dynamic intensity-modulated radiation therapy (dIMRT) and step-and-shoot IMRT (ssIMRT) for different treatment sites.Materials and methods:Twelve patients were selected for the planning comparison study. This included three head and neck, three brain, three rectal and three cervical cancer patients. Total dose of 50 Gy was given for all the plans. Plans were done for Elekta synergy with Monaco treatment planning system. All plans were generated with 6 MV photons beam. Plan evaluation was based on the ability to meet the dose volume histogram, dose homogeneity index, conformity index and radiation delivery time, and monitor unit needs to deliver the prescribed dose.Results:The VMAT and dIMRT plans achieved the better conformity (CI98% = 0·965 ± 0·023) and (CI98% = 0·939 ± 0·01), respectively, while ssIMRT plans were slightly inferior (CI98% = 0·901 ± 0·038). The inhomogeneity in the planning target volume (PTV) was highest with ssIMRT with HI equal to 0·097 ± 0·015 when compared to VMAT with HI equal to 0·092 ± 0·0369 and 0·095 ± 0·023 with dIMRT. The integral dose is found to be inferior with VMAT 105·31 ± 53·6 (Gy L) when compared with dIMRT 110·75 ± 52·9 (Gy L) and ssIMRT 115 38 ± 55·1(Gy L). All the techniques respected the planning objective for all organs at risk. The delivery time per fraction for VMAT was much lower than dIMRT and ssIMRT.Findings:Our results indicate that dIMRT and VMAT provide better sparing of normal tissue, homogeneity and conformity than ssIMRT with reduced treatment delivery time.

scholarly journals Image guided high-dose-rate brachytherapy versus volumetric modulated arc therapy for head and neck cancer: A comparative analysis of dosimetry for target volume and organs at risk

2018 ◽  
Vol 52 (4) ◽  
pp. 461-467
Author(s):  
Hironori Akiyama ◽  
Csilla Pesznyák ◽  
Dalma Béla ◽  
Örs Ferenczi ◽  
Tibor Major ◽  
...  
Keyword(s):  
Head And Neck Cancer ◽  
Head And Neck ◽  
Dose Rate ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
High Dose Rate ◽  
High Dose ◽  
Image Guided ◽  
Arc Therapy

Abstract Background The aim of the study was to present dosimetric comparison of image guided high-dose-rate brachytherapy (IGBT) with volumetric modulated arc therapy (VMAT) for head and neck cancer regarding conformity of dose distribution to planning target volume (PTV) and doses to organs at risk (OARs). Patients and methods Thirty-eight consecutive patients with T1-4 mobile tongue, floor of mouth and base of tongue cancer treated with IGBT were selected. For these patients additional VMAT treatment plans were also prepared using identical computed tomography data. OARs and PTV related parameters (e.g. V98, D0.1cm3, Dmean, etc.) were compared. Results Mean V98 of the PTV was 90.2% vs. 90.4% (p > 0.05) for IGBT and VMAT, respectively. Mean D0.1cm3 to the mandible was 77.0% vs. 85.4% (p < 0.05). Dmean to ipsilateral and contralateral parotid glands was 4.6% vs. 4.6% and 3.0% vs. 3.9% (p > 0.05). Dmean to ipsilateral and contralateral submandibular glands was 16.4% vs. 21.9% (p > 0.05) and 8.2% vs. 16.9% (p < 0.05), respectively. Conclusions Both techniques showed excellent target coverage. With IGBT dose to normal tissues was lower than with VMAT. The results prove the superiority of IGBT in the protection of OARs and the important role of this invasive method in the era of new external beam techniques.

Volumetric modulated arc therapy versus 3D conformal radiotherapy for selected childhood neoplasms

2014 ◽  
Vol 14 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Marzanna Chojnacka ◽  
Anna Zygmuntowicz-Piętka ◽  
Anna Semaniak ◽  
Katarzyna Pędziwiatr ◽  
Ryszard Dąbrowski ◽  
...  
Keyword(s):  
At Risk ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Conformal Radiotherapy ◽  
Target Volume ◽  
High Dose ◽  
Dose Volume Histograms ◽  
Dose Volume ◽  
Arc Therapy ◽  
Childhood Neoplasms

AbstractAimThe comparative study of the plan quality between volumetric modulated arc therapy (VMAT) and 3D conformal therapy (3DCRT) for the treatment of selected representative childhood neoplasms was performed.Materials and methodsDuring the year 2013, 44 children with neoplasms were irradiated using VMAT. The 3DCRT plans were created retrospectively and compared with the VMAT plans for four tumour locations. The conformity parameters, dose volume histograms for target volume and organs at risk, number of monitor units and time used to deliver the single fraction were evaluated and compared for each plan. Additionally, for patients with brain tumour the comparison of different arcs configuration was made.ResultsVMAT modality presented the superiority over older conformal methods with regard to the improvement in the dose conformity and normal tissue sparing. The noncoplanar arcs arrangement was beneficial in the decrease of high-dose volume and the protection of the organs at risk located oppositely to the target volume.FindingsVMAT could be preferred technique for treating childhood neoplasms, especially when the complex-shaped target volume is localised close to the critical structures. The noncoplanar arcs arrangement could be the method of choice in the reirradiated patients and in these with laterally located brain tumours.

The importance of collimator angle error in volumetric-modulated arc therapy

2015 ◽  
pp. 1-8
Author(s):  
Vicente Puchades-Puchades ◽  
Alfredo Serna-Berná ◽  
Fernando Mata-Colodro ◽  
David Ramos-Amores ◽  
Miguel Alcaraz-Baños
Keyword(s):  
High Risk ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Low Risk ◽  
Angle Error ◽  
Dose Volume Histograms ◽  
Original Plan ◽  
Collimator Angle ◽  
Arc Therapy

AbstractPurposeTo evaluate the dosimetric errors associated with the effect of the collimator angle error in volumetric-modulated arc therapy (VMAT) treatments.Methods and materialsFour patients with different planning target volume (PTV) and localisations treated using VMAT were analysed (high-risk prostate, low-risk prostate, head and neck (H&amp;N) and holocranial with hippocampus protection) in terms of dosimetric variations when errors in the collimator angle were introduced. Original plans underwent modifications of the planned collimator angles of ±0·5°, ±1° and ±1·5°. These modified plans were re-calculated using the same original plan fluencies, and the resulting dose–volume histograms and homogeneity index (HI-ICRU) were compared.ResultsFor the high-risk prostate case, there was a noticeable loss of PTV dose coverage for collimator angle errors larger than ±1°, with HI-ICRU relative variations up to 75% in the range analysed. The low-risk prostate case did not present significant changes in organs at risk or PTV dose coverage. For the H&amp;N case, the spinal cord presented changes around 4% forD0·1 cc. In the holocranial case, optic lens showed dose variations up to 5% for collimator angle errors larger than ±1°.ConclusionsThe effect of the collimator error in VMAT increased as the PTV increased.For selecting the position of the isocentre, one should be cautious, and whenever possible choose a position close to the geometrical centre of the PTVs in order to avoid or minimise errors from the calibration of the collimator angle.

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.

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 ◽  
Pass Rates ◽  
Flattening Filter Free ◽  
Arc Therapy ◽  
Dosimetric Accuracy ◽  
Planning Technique ◽  
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 applied to non-coplanar volumetric-modulated arc therapy (VMAT) technique, is associated with high conformity and rapid dose fall-off, the performance of HyperArc for total scalp irradiation has not been explored. The current study aimed to compare the dosimetric performance of HyperArc plans with those of non-coplanar VMAT plans in angiosarcoma of the scalp. Methods: Ten patients with angiosarcoma of the scalp were included in this study. The performance of three different plans administered using TrueBeam Edge were compared: non-coplanar 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 each of these plans were evaluated. Results: The three plans showed no statistically significant differences in target volume coverage, conformity, and homogeneity. The HyperArc-FF and HyperArc-FFF plans provided significantly lower mean brain doses (12.63 ± 3.31 Gy and 12.71 ± 3.40 Gy) than did the VMAT-FF plans (17.11 ± 5.25 Gy). 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 provided a shorter beam-on time than did the VMAT-FF plan. The 3%/2 mm gamma test pass rates were above 95% for all three plans. Conclusions: Our results suggest that the HyperArc plan can be potentially used for radiation therapy of target regions with large and complicated shapes, such as the scalp, and that there are no advantages of using FFF beams.

scholarly journals The Capabilities and Characteristics of Helical Tomotherapy and Co-Planar Dual Arcs Volumetric-Modulated arc Therapy Associated with Hippocampal Sparing During Prophylactic Cranial Irradiation

2021 ◽  
Vol 20 ◽  
pp. 153303382110439
Author(s):  
Dandan Wang ◽  
Xingmin Ma ◽  
Lu Fu ◽  
Jiabing Gu ◽  
Tong Bai ◽  
...  
Keyword(s):  
At Risk ◽  
Planning Target Volume ◽  
Helical Tomotherapy ◽  
Organs At Risk ◽  
Volumetric Modulated Arc Therapy ◽  
Target Volume ◽  
Cranial Irradiation ◽  
Prophylactic Cranial Irradiation ◽  
Target Coverage ◽  
Arc Therapy

Objective: To investigate the features of helical tomotherapy and co-planar dual Arcs volumetric-modulated arc therapy during prophylactic cranial irradiation associated with bilateral hippocampal tissue sparing. Materials and methods: Helical tomotherapy and co-planar dual arcs volumetric-modulated arc therapy treatment plans were generated with a dose of 30 Gy/10 fractions in 16 patients treated with prophylactic cranial irradiation. The dose to the bilateral hippocampal tissues, organs at risk, and planning target volume were determined when the average dose of bilateral hippocampal tissues was reduced by approximately 4 Gy as an observation point. Changes in dosimetry when sparing the bilateral hippocampal tissues were determined for both modalities. Results: When bilateral hippocampal tissues were restricted to 8 Gy, D40%mean-bilateral hippocampal tissues = 7.64 ± 0.41 Gy in helical tomotherapy, while D40%mean-bilateral hippocampal tissues = 10.96 ± 0.38 Gy in co-planar dual arcs volumetric-modulated arc therapy volumetric-modulated arc therapy. Helical tomotherapy was associated with significantly lower doses to organs at risk, including Dmean-bilateral hippocampal tissues ( P = .03), D98%-bilateral hippocampal tissues ( P = .01), D2%-bilateral hippocampal tissues ( P = .01), Dmean-inner ear ( P = .02), Dmean-parotid glands ( P = .02), Dmax-lens ( P = .02), and Dmax-brainstem ( P = .02), but not Dmax-optic nerves ( P = .87). Helical tomotherapy provided better target coverage, with lower average D2%-PTV ( P = .02), higher average D98%-PTV ( P = .02), and better conformal index (0.87 vs 0.84, P = .02) and homogeneity index (0.15 vs 0.21, P = .05). With smaller bilateral hippocampal tissues doses, the planning target volume dose changed across 3 dosimetry regions for both modalities; the plateau region (>20.0 Gy for helical tomotherapy versus >16.0 Gy for co-planar dual arcs volumetric-modulated arc therapy), gradient region (20.0-12.0 Gy vs 16.0-11.0 Gy), and falling region (<12.0 Gy vs <11.0 Gy). The average delivery duration of helical tomotherapy was almost 7.7 times longer than that of co-planar dual arcs volumetric-modulated arc therapy. Conclusions: Helical tomotherapy was better at sparing the bilateral hippocampal tissues and organs at risk and had better target coverage but a significantly longer treatment duration than co-planar dual arcs volumetric-modulated arc therapy. Further dose decreases in the bilateral hippocampal tissues would yield worse target dose coverage.

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