Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

Hamilton, Russell J.; Kuchnir, Franca T.; Sweeney, Patrick J.; Rubin, Steven J.; Dujovny, Manuel; Pelizzari, Charles A.; Chen, George T.Y.

doi:10.1016/0360-3016(95)00275-8

Cited by 65 publications

(23 citation statements)

References 13 publications

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“…The mean dose to the total brain increased which can be explained by the increase in dose heterogeneity and the larger volume receiving lower doses which is characteristic of conformal treatment methods. 35 The results of this study represent a small but significant step in the treatment of MB and provide a basis for further dose reductions in these patients. Our current trial includes further reductions in dose and volume: patients with average risk MB now receive 23.4 Gy CSI followed by treatment of the primary site using a 1 cm clinical target volume margin and the same chemotherapy.…”

Section: Discussionmentioning

confidence: 84%

Multi-Institution Prospective Trial of Reduced-Dose Craniospinal Irradiation (23.4 Gy) Followed by Conformal Posterior Fossa (36 Gy) and Primary Site Irradiation (55.8 Gy) and Dose-Intensive Chemotherapy for Average-Risk Medulloblastoma

Merchant¹,

Kun²,

Krasin³

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

153

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Purpose/Objective-Limiting neurocognitive sequelae of radiation therapy (RT) has been an objective in the treatment of medulloblastoma (MB). Conformal RT to less than the entire posterior fossa (PF) after craniospinal irradiation (CSI) may reduce neurocognitive sequelae and requires evaluation. October 1996 and August 2003, 86 patients, 3-21 years of age, with newly diagnosed, average-risk MB were treated on a prospective, IRB-approved, multi-institution trial of risk-adapted RT and dose-intensive chemotherapy. RT began within 28 days of definitive surgery and consisted of CSI (23.4 Gy), conformal PF RT (36.0 Gy) and primary site RT (55.8 Gy). The planning target volume for the primary site included the post-operative tumor bed surrounded by an anatomically confined margin of 2 cm which was then expanded with a geometric margin of Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Materials/Methods-Between CONFLICT OF INTEREST NOTIFICATION:There are no conflicts of interest with the authors or materials in this manuscript. NIH Public Access NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript 0.3-0.5 cm. Chemotherapy was initiated 6 weeks after RT and included 4 cycles of high-dose cyclophosphamide, cisplatin and vincristine.Results-With a median follow-up of 61.2 months (5.2-115.0 months), the estimated 5-year eventfree survival and cumulative incidence of PF failure were 83.0% ± 5.3% and 4.9% ± 2.4% (±SE), respectively. Targeting guidelines used in this study resulted in a mean reduction of 13% in the volume of the PF receiving doses above 55Gy compared to conventionally planned RT. Reductions in dose to the temporal lobes, cochleae and hypothalamus were statistically significant.Conclusions-This prospective trial demonstrates that irradiation of less than the entire PF after 23.4 Gy CSI for average-risk MB results in disease control comparable to treatment of the entire PF.

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Section: Discussionmentioning

confidence: 84%

Multi-Institution Prospective Trial of Reduced-Dose Craniospinal Irradiation (23.4 Gy) Followed by Conformal Posterior Fossa (36 Gy) and Primary Site Irradiation (55.8 Gy) and Dose-Intensive Chemotherapy for Average-Risk Medulloblastoma

Merchant¹,

Kun²,

Krasin³

et al. 2008

International Journal of Radiation Oncology*Biology*Physics

153

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“…This is realized by using dedicated MLC system with smaller leaves. Studies have shown that, with smaller MLC leaves, linear accelerator‐based SRS with multiple static beams allows better normal tissue sparing for irregular shaped targets than the multiple arching beams using the circular collimators 18 , 19 . One of the important studies to assess the impact of MLC on dose distribution was performed by Bortfeld et al (4) They showed that theoretically calculated optimum leaf width for 6 MV photon beam was in the range of

1.5 - 2.0 mm

.…”

Section: Discussionmentioning

confidence: 99%

Is 5 mm MMLC suitable for VMAT‐based lung SBRT? A dosimetric comparison with 2.5 mm HDMLC using RTOG‐0813 treatment planning criteria for both conventional and high‐dose flattening filter‐free photon beams

Subramanian

Subramani

Swamy

et al. 2015

J Applied Clin Med Phys

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The aim of this study is to assess the suitability of 5 mm millennium multileaf collimator (MMLC) for volumetric‐modulated arc therapy (VMAT)‐based lung stereotactic body radiotherapy (SBRT). Thirty lung SBRT patient treatment plans along with their planning target volumes (ranging from 2.01 cc to 150.11 cc) were transferred to an inhomogeneous lung phantom and retrospectively planned using VMAT technique, along with the high definition multileaf collimator (HDMLC) and MMLC systems. The plans were evaluated using Radiation Therapy Oncology Group (RTOG‐0813) treatment planning criteria for target coverage, normal tissue sparing, and treatment efficiency for both the MMLC and HDMLC systems using flat and flattening filter‐free (FFF) photon beams. Irrespective of the target volumes, both the MLC systems were able to satisfy the RTOG‐0813 treatment planning criteria without having any major deviation. Dose conformity was marginally better with HDMLC. The average conformity index (CI) value was found to be 1.069±0.034 and 1.075±0.0380 for HDMLC and MMLC plans, respectively. For the 6 MV FFF beams, the plan was slightly more conformal, with the average CI values of 1.063±0.029 and 1.073±0.033 for the HDMLC and MMLC plans, respectively. The high dose spillage was the maximum for 2 cc volume set (3% for HDMLC and 3.1% for MMLC). In the case of low dose spillage, both the MLCs were within the protocol of no deviation, except for the 2 cc volume set. The results from this study revealed that VMAT‐based lung SBRT using 5 mm MMLC satisfies the RTOG‐0813 treatment planning criteria for the studied target size and shapes.PACS numbers: 87.53.Ly, 87.53D, 87.56.jk

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“…For Iinac-based SRS with circular collimators, the planner strives to minimize the number of isocenters in a plan due to the inefficient beam delivery (28)(29)(30). For linac-based SRS with mMLCs, only one isocenter is used (4,(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). The planning methods are similar to the planning for external beam radiation therapy.…”

Section: Yu and Shepardmentioning

confidence: 99%

“…These include the use of multiple fixed fields (4,(7)(8)(9)(10)(11)(12)(13)(14)(15), dynamic conformal arcs (17,18), multiple fixed intensity-modulated fields with inverse planning (9,16). In some planning systems, the weights of the beams and/or arcs can be optimized (16).…”

Section: Introductionmentioning

confidence: 99%

“…Additional delivery methods include: (i) the use of fixed open fields (4,(7)(8)(9)(10)(11)(12)(13)(14)(15) and intensity modulated fields delivered with micro multileaf collimators (mMLCs) (9,16); (ii) the use of dynamic conformal arcs, in which the MLC shape changes as the beam is rotating around the target (17,18); (iii) the Cyber Knife" (Accuray, Inc., Sunnyville, CA) using an x-band linac mounted on a robotic arm (19); and (iv) rotational intensity-modulated beam delivery (20)(21)(22)(23)(24)(25). Online image-guidance has also been developed to ensure accurate targeting of radiation beams (4,26,27).…”

Section: Introductionmentioning

confidence: 99%

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Treatment Planning for Stereotactic Radiosurgery with Photon Beams

Shepard

2003

Technol Cancer Res Treat

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www.tcrt.org .Stereotactic Radiosurgery (SRS) has evolved as a unique discipline that combines aspects of both surgery and radiation oncology. Technological developments in the past few decades have provided a wide array of treatment techniques, including (i) the Gamma KnifeTM; (ii) Linac-based stereotactic techniques using circular collimators or using micro multileaf collimators (mMLCs); (iii) the Cyber KnifeTM. using an x-band Iinac mounted on a robotic arm; and (iv) serial and spiral tomotherapy. This paper provides a review of the treatment planning methods for stereotactic radiosurgery. Because of the differences in planning strategies used for each SRS technique. this paper will provide both a general review of the pre-requisites and common features of SRS treatment planning and the planning techniques specific to each of the SRS techniques.

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Comparison of static conformal field with multiple noncoplanar arc techniques for stereotactic radiosurgery or stereotactic radiotherapy

Cited by 65 publications

References 13 publications

Multi-Institution Prospective Trial of Reduced-Dose Craniospinal Irradiation (23.4 Gy) Followed by Conformal Posterior Fossa (36 Gy) and Primary Site Irradiation (55.8 Gy) and Dose-Intensive Chemotherapy for Average-Risk Medulloblastoma

Multi-Institution Prospective Trial of Reduced-Dose Craniospinal Irradiation (23.4 Gy) Followed by Conformal Posterior Fossa (36 Gy) and Primary Site Irradiation (55.8 Gy) and Dose-Intensive Chemotherapy for Average-Risk Medulloblastoma

Is 5 mm MMLC suitable for VMAT‐based lung SBRT? A dosimetric comparison with 2.5 mm HDMLC using RTOG‐0813 treatment planning criteria for both conventional and high‐dose flattening filter‐free photon beams

Treatment Planning for Stereotactic Radiosurgery with Photon Beams

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