Dosimetric Comparison of Craniospinal Axis Irradiation (CSI) Treatments Using Helical Tomotherapy, Smartarc&amp;lt;sup&amp;gt;TM&amp;lt;/sup&amp;gt;, and 3D Conventional Radiation Therapy

Myers, Pamela; Stathakis, Sotirios; Gutiérrez, Alonso N.; Esquivel, Carlos O.; Mavroidis, P.; Papanikolaou, Niko

doi:10.4236/ijmpcero.2013.21005

Cited by 17 publications

(17 citation statements)

References 17 publications

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“…The plan approval clinical criteria required that 95% of the planning target volume (PTV) should receive at least the prescription dose, and the dose to the involved critical organs (lungs, heart, kidneys, orbits, liver, colon, thyroid, and breasts for the female patients) should be below their tolerance limits as defined in the QUANTEC report (8) . The PTV encompassed the whole brain and the entire spinal cord with a 0.7 cm isotropic expansion (7) . The patient's respective physician delineated all the structures and defined the dose prescription prior to planning, and those factors were kept unchanged during the production of all the plans in each individual case.…”

Section: Methodsmentioning

confidence: 99%

“…The outcome of the plan can depend heavily on not only the dose given to normal tissues and the target, but also the specific dose distribution and the dose response of the involved organs. Relevant studies have been published concerning these outcomes for adult patients of varying disease sites for different treatment modalities using dosimetric and radiobiological analyses (6,7) . These studies, however, are limited in their applicability to pediatric CSI patients due to the different radiosensitivity that characterizes these young patients.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning

Myers

Mavroidis

Papanikolaou

et al. 2014

J Applied Clin Med Phys

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Currently, radiotherapy treatment plan acceptance is based primarily on dosimetric performance measures. However, use of radiobiological analysis to assess benefit in terms of tumor control and harm in terms of injury to normal tissues can be advantageous. For pediatric craniospinal axis irradiation (CSI) patients, in particular, knowing the technique that will optimize the probabilities of benefit versus injury can lead to better long‐term outcomes. Twenty‐four CSI pediatric patients (median age 10) were retrospectively planned with three techniques: three‐dimensional conformal radiation therapy (3D CRT), volumetric‐modulated arc therapy (VMAT), and helical tomotherapy (HT). VMAT plans consisted of one superior and one inferior full arc, and tomotherapy plans were created using a 5.02 cm field width and helical pitch of 0.287. Each plan was normalized to 95% of target volume (whole brain and spinal cord) receiving prescription dose 23.4 Gy in 13 fractions. Using an in‐house MATLAB code and DVH data from each plan, the three techniques were evaluated based on biologically effective uniform dose (Dfalse¯false¯), the complication‐free tumor control probability (normalP+), and the width of the therapeutically beneficial range. Overall, 3D CRT and VMAT plans had similar values of Dfalse¯false¯ (24.1 and 24.2 Gy), while HT had a Dfalse¯false¯ slightly lower (23.6 Gy). The average values of the normalP+ index were 64.6, 67.4, and 56.6% for 3D CRT, VMAT, and HT plans, respectively, with the VMAT plans having a statistically significant increase in normalP+. Optimal values of Dfalse¯false¯ were 28.4, 33.0, and 31.9 Gy for 3D CRT, VMAT, and HT plans, respectively. Although normalP+ values that correspond to the initial dose prescription were lower for HT, after optimizing the Dfalse¯false¯ prescription level, the optimal normalP+ became 94.1, 99.5, and 99.6% for 3D CRT, VMAT, and HT, respectively, with the VMAT and HT plans having statistically significant increases in normalP+. If the optimal dose level is prescribed using a radiobiological evaluation method, as opposed to a purely dosimetric one, the two IMRT techniques, VMAT and HT, will yield largest overall benefit to CSI patients by maximizing tumor control and limiting normal tissue injury. Using VMAT or HT may provide these pediatric patients with better long‐term outcomes after radiotherapy.PACS number: 87.55.dk

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning

Myers

Mavroidis

Papanikolaou

et al. 2014

J Applied Clin Med Phys

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“…Fractions of 1.8 Gy were prescribed to a total number of 13 fractions for each plan. The different plans were optimized to meet the acceptance criteria according to which at least 95% of the volume of the PTV should receive the prescribed dose (37). A single planner designed, evaluated, and completed each of the plans for all the modalities involved according to institutional policies for purposes of consistency.…”

Section: Treatment Setup Prescription and Modalitiesmentioning

confidence: 99%

Pediatric Cranio-spinal Axis Irradiation

Myers

Mavroidis

Komisopoulos

et al. 2015

Technol Cancer Res Treat

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Pediatric cranio-spinal axis irradiation (CSI) is a valuable treatment for many central nervous system (CNS) diseases, but due to the life expectancies and quality of life expectations for children, the minimization of the risk for radiation-induced secondary malignancies must be a high priority. This study compared the estimated CSI-induced secondary malignancy risks of three radiation therapy modalities using three different models. Twenty-four (n 5 24) pediatric patients previously treated with CSI for tumors of the CNS were planned using three different treatment modalities: three-dimensional conformal radiation therapy (3D-CRT), volume modulated arc therapy (VMAT), and Tomotherapy. Each plan was designed to deliver 23.4 Gy (1.8 Gy/fraction) to the target which was defined as the entire brain and spinal column with a 0.7 cm expansion. The mean doses as well as the dose volume histograms (DVH) of specific organs were analyzed for secondary malignancy risk according to three different methods: the effective dose equivalent (EDE), the excess relative risk (ERR), and the linear quadratic (LQ) models. Using the EDE model, the average secondary risk was highest for the 3D-CRT plans (37.60%), compared to VMAT (28.05%) and Tomotherapy (27.90%). The ERR model showed similarly that the 3D-CRT plans had considerably higher risk (10.84%) than VMAT and Tomotherapy, which showed almost equal risks (7.05 and 7.07%, respectively). The LQ model requires organ-specific cell survival parameters, which for the lungs, heart, and breast relevant values were found and applied. The lung risk for secondary malignancy was found to be 1.00, 1.96, and 2.07% for 3D-CRT, VMAT, and Tomotherapy, respectively. The secondary cancer risk for breast was estimated to be 0.09, 0.21, and 0.27% and for heart it was 9.75, 6.02 and 6.29% for 3D-CRT, VMAT, and Tomotherapy, respectively. Based on three methods of secondary malignancy estimation, the 3D-CRT plans produced highest radiationinduced secondary malignancy risk, and the VMAT and Tomotherapy plans had nearly equal risk. Pediatric patients must be treated with reducing long term sequelae as a priority.

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“…Dozimetrik olarak daha üstün bir plan olmasına rağmen tedavi süresinin uzun olması intrafraksiyon organ hareketine sebep olabileceği düşüncesini doğurmaktadır. [20,21] Bizim çalışmamızda da tedavi süresi IMRT planlarına göre oldukça yüksek çıkmıştır. Ayrıca yapılan çalışmada tomoterapi ile yapılan planda tüm vücut dozu diğer planlama sistemlerine göre daha fazla çıktığı görüldü.…”

Section: İntegral Dozunclassified

“…Myers ve ark.nın [20] yaptığı çalışmaya göre tomoterapi planları, 5 cm alan genişliği, 0.287 pitch değerinde ve 2 modülasyon faktöründe oluşturuldu. Tedavi sürelerini ortalamada 1902.1s olarak buldular.…”

Section: İntegral Dozunclassified

A comparative planning study of step -and -shoot IMRT versus helical tomotherapy IMRT in the treatment of craniospinal tumor

Onay¹

2014

TJ Oncol

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Dosimetric Comparison of Craniospinal Axis Irradiation (CSI) Treatments Using Helical Tomotherapy, Smartarc<sup>TM</sup>, and 3D Conventional Radiation Therapy

Cited by 17 publications

References 17 publications

Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning

Comparing conformal, arc radiotherapy and helical tomotherapy in craniospinal irradiation planning

Pediatric Cranio-spinal Axis Irradiation

A comparative planning study of step -and -shoot IMRT versus helical tomotherapy IMRT in the treatment of craniospinal tumor

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