The Use of Photon Beams of a Flattening Filter-free Linear Accelerator for Hypofractionated Volumetric Modulated Arc Therapy in Localized Prostate Cancer

Zwahlen, Daniel R.; Lang, Stephanie; Hrbáček, Jan; Glanzmann, Christoph; Kloeck, S.; Najafi, Yousef; Streller, Tino; Studer, Gabriela; Zaugg, Kathrin; Luetolf, U.M.

doi:10.1016/j.ijrobp.2011.10.019

Cited by 55 publications

(51 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…21 Kim et al 18 also reported the same based on a study of monitoring unit efficiency for flattening-filter free photon beam in association with tumor size and location. Increased MUs for FFFB in comparison to FB were also reported by Rout et al 22 and Zwahlen et al 23 in their findings.…”

Section: Discussionsupporting

confidence: 81%

Dosimetric influence of filtered and flattening filter free photon beam on rapid arc (RA) radiotherapy planning in case of cervix carcinoma

Kumar

Yadav

Samuvel

et al. 2017

Reports of Practical Oncology & Radiotherapy

View full text Add to dashboard Cite

show abstract

Section: Discussionsupporting

confidence: 81%

Dosimetric influence of filtered and flattening filter free photon beam on rapid arc (RA) radiotherapy planning in case of cervix carcinoma

Kumar

Yadav

Samuvel

et al. 2017

Reports of Practical Oncology & Radiotherapy

View full text Add to dashboard Cite

show abstract

“…From January 2009 to April 2012, 20 non-consecutive patients with histologically proven low- (LR), intermediate- (IR) or high-risk (HR) adenocarcinoma of the prostate were treated according to the CHHIP (Conventional or Hypofractionated High Dose Intensity Modulated Radiotherapy for Prostate Cancer) protocol [8], and according to randomization VMAT (RapidArc®) was used to a dose of 74Gy/37f (n = 14), 60Gy/20f (n = 1) or 57Gy/19f (n = 5) at the University Hospital Zürich, Switzerland [9]. Hypofractionation schedules were used only for patients randomized within the CHHIP trial (open between 2010 and 2011 at Zurich) and not off-study, since hypofractionation was not standard at that time.…”

Section: Methodsmentioning

confidence: 99%

PTV margin definition in hypofractionated IGRT of localized prostate cancer using cone beam CT and orthogonal image pairs with fiducial markers

et al. 2014

Self Cite

View full text Add to dashboard Cite

PurposeTo evaluate PTV margins for hypofractionated IGRT of prostate comparing kV/kV imaging or CBCT.Patients and methodsBetween 2009 and 2012, 20 patients with low- (LR), intermediate- (IR) and high-risk (HR) prostate cancer were treated with VMAT in supine position with fiducial markers (FM), endorectal balloon (ERB) and full bladder. CBCT’s and kV/kV imaging were performed before and additional CBCT’s after treatment assessing intra-fraction motion. CTVP for 5 patients with LR and CTVPSV for 5 patients with IR/HR prostate cancer were contoured independently by 3 radiation oncologists using MRI. The van Hark formula (PTV margin =2.5Σ +0.7σ) was applied to calculate PTV margins of prostate/seminal vesicles (P/PSV) using CBCT or FM.Results172 and 52 CBCTs before and after RT and 507 kV/kV images before RT were analysed. Differences between FM in CBCT or in planar kV image pairs were below 1 mm. Accounting for both random and systematic uncertainties anisotropic PTV margins were 5-8 mm for P (LR) and 6-11 mm for PSV (IR/HR). Random uncertainties like intra-fraction and inter-fraction (setup) uncertainties were of similar magnitude (0.9-1.4 mm). Largest uncertainty was introduced by CTV delineation (LR: 1-2 mm, IR/HR: 1.6-3.5 mm). Patient positioning using bone matching or ERB-matching resulted in larger PTV margins.ConclusionsFor IGRT CBCT or kV/kV-image pairs with FM are interchangeable in respect of accuracy. Especially for hypofractionated RT, PTV margins can be kept in the range of 5 mm or below if stringent daily IGRT, ideally including prostate tracking, is applied. MR-based CTV delineation optimization is recommended.

show abstract

“…[8] During the past years, feasibility of treating various cancers including prostate, lung, larynx, chest wall, and esophagus using unflattened beams have been reported. [910111213141516] Also exclusive use of a linear accelerator in FFF mode in 3D CRT planning has also been reported to be feasible. [17] From all these published results, a reduced beam on time (BOT) and comparable plan quality seem to have been confirmed for VMAT plan with unflattened beams.…”

Section: Introductionmentioning

confidence: 99%

A dosimetric evaluation of flattening filter-free volumetric modulated arc therapy in nasopharyngeal carcinoma

Song

et al. 2014

J Med Phys

View full text Add to dashboard Cite

Purpose:To explore the dosimetric effects of flattening filter-free (FFF) beams in volumetric modulated arc therapy (VMAT) of nasopharyngeal carcinoma via a retrospective planning study.Materials and Methods:A linear accelerator (LINAC) was prepared to operate in FFF mode and the beam data were collected and used to build a model in TPS. For 10 nasopharyngeal carcinoma (NPC) cases, VMAT plans of FFF beams and normal flattened (FF) beams were designed. Differences of plan quality and delivery efficiency between FFF-VMAT plans and filter filtered VMAT (FF-VMAT) plans were analyzed using two-tailed paired t-tests.Results:Removal of the flattening filter increased the dose rate. Averaged beam on time (BOT) of FFF-VMAT plans was decreased by 24.2%. Differences of target dose coverage between plans with flattened and unflattened beams were statistically insignificant. For dose to normal organs, up to 4.9% decrease in V35 of parotid grand and 4.5% decrease in averaged normal tissue (NT) dose was observed.Conclusions:The TPS used in our study was able to handle FFF beams. The FFF beam prone to improve the normal tissue sparing while achieving similar target dose distribution. Decreasing of BOT in NPC cases was valuable in terms of patient's comfort.

show abstract

The Use of Photon Beams of a Flattening Filter-free Linear Accelerator for Hypofractionated Volumetric Modulated Arc Therapy in Localized Prostate Cancer

Cited by 55 publications

References 19 publications

Dosimetric influence of filtered and flattening filter free photon beam on rapid arc (RA) radiotherapy planning in case of cervix carcinoma

Dosimetric influence of filtered and flattening filter free photon beam on rapid arc (RA) radiotherapy planning in case of cervix carcinoma

PTV margin definition in hypofractionated IGRT of localized prostate cancer using cone beam CT and orthogonal image pairs with fiducial markers

A dosimetric evaluation of flattening filter-free volumetric modulated arc therapy in nasopharyngeal carcinoma

Contact Info

Product

Resources

About