Purpose: To evaluate, with a dosimetric and clinical feasibility study, RapidArc (a volumetric modulated arc technique) for hypofractionated stereotactic radiotherapy treatment of large arteriovenous malformations (AVMs).

Methods And Materials: Nine patients were subject to multimodality imaging (magnetic resonance, computed tomography, and digital subtraction angiography) to determine nidus and target volumes, as well as involved organs at risk (optical structures, inner ear, brain stem). Plans for multiple intensity-modulated arcs with a single isocenter were optimized for a fractionation of 25 Gy in 5 fractions. All plans were optimized for 6-MV photon beams. Dose-volume histograms were analyzed to assess plan quality. Delivery parameters were reported to appraise technical features of RapidArc, and pretreatment quality assurance measurements were carried out to report on quality of delivery.

Results: Average size of AVM nidus was 26.2 cm(3), and RapidArc plans provided complete target coverage with minimal overdosage (V(100%) = 100% and V(110%) < 1%) and excellent homogeneity (<6%). Organs at risk were highly spared. The D(1%) to chiasm, eyes, lenses, optic nerves, and brainstem (mean ± SD) was 6.4 ± 8.3, 1.9 ± 3.8, 2.3 ± 2.2, 0.7 ± 0.9, 4.4 ± 7.2, 12.2 ± 9.6 Gy, respectively. Conformity index (CI(95%)) was 2.2 ± 0.1. The number of monitor units per gray was 277 ± 45, total beam-on time was 2.5 ± 0.3 min. Planning vs. delivery γ pass rate was 98.3% ± 0.9%. None of the patients developed acute toxicity. With a median follow-up of 9 months, 3 patients presented with deterioration of symptoms and were found to have postradiation changes but responded symptomatically to steroids. These patients continue to do well on follow-up. One patient developed headache and seizures, which was attributed to intracranial bleed, confirmed on imaging.

Conclusion: Hypofractionated stereotactic radiotherapy can be successfully delivered using the RapidArc form of volumetric arc technology for intracranial AVMs. The quality of delivery and calculated parameters are in agreement with each other and are in line with published reports for other sites.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijrobp.2011.02.005DOI Listing

Publication Analysis

Top Keywords

volumetric modulated
8
hypofractionated stereotactic
8
stereotactic radiotherapy
8
radiotherapy treatment
8
arteriovenous malformations
8
modulated arc-based
4
arc-based hypofractionated
4
treatment selected
4
selected intracranial
4
intracranial arteriovenous
4

Similar Publications

Background And Purpose: In lung stereotactic body radiation therapy (SBRT) using a breath-holding technique, displacement of tumor during breath-holding is rarely considered. This study used four-dimensional (4D) dose calculation with cine computed tomography (CT) to evaluate the impact of unexpected tumor position displacement during breath-holding on the target dose of lung volumetric modulated arc therapy (VMAT)-SBRT.

Materials And Methods: This study included 20 cases for which tumor position displacement during end-exhalation breath-holding (range: 0.

View Article and Find Full Text PDF

Aim: This study leveraged standard-of-care CT scans of patients receiving unilateral radiotherapy (RT) for early tonsillar cancer to detect volumetric changes in the carotid arteries, and determine whether there is a dose-response relationship.

Methods: Disease-free cancer survivors (>3 months since therapy and age > 18 years) treated with intensity modulated RT for early (T1-2, N0-2b) tonsillar cancer with pre- and post-therapy contrast-enhanced CT scans available were included. Patients treated with definitive surgery, bilateral RT, or additional RT before the post-RT CT scan were excluded.

View Article and Find Full Text PDF

Background: The treatment of glioblastomas (GBM) with radiation therapy is extremely challenging due to their invasive nature and high recurrence rate within normal brain tissue.

Purpose: In this work, we present a new metric called the tumour spread (TS) map, which utilizes diffusion tensor imaging (DTI) to predict the probable direction of tumour cells spread along fiber tracts. We hypothesized that the TS map could serve as a predictive tool for identifying patterns of likely recurrence in patients with GBM and, therefore, be used to modify the delivery of radiation treatment to pre-emptively target regions at high risk of tumour spread.

View Article and Find Full Text PDF

: Autosomal Dominant Polycystic Kidney Disease (ADPKD) is mainly characterized by renal involvement with progressive bilateral development of renal cysts and volumetric increase in the kidneys, causing a loss of renal function, chronic kidney disease (CKD), and kidney failure. The occurrence of mosaicism may modulate the clinical course of the disease. Mosaicism is characterized by a few cell populations with different genomes.

View Article and Find Full Text PDF

Background: Radiotherapy for thymoma is delivered post-operatively in selected cases. Given the particular location of the thymic bed and the excellent prognosis, late cardiac toxicities may be an issue. The purpose of this retrospective dosimetric study is to investigate whether intensity-modulated proton beam therapy (IMPT) compared to photon therapy could better spare cardiac substructures, given prespecified dose constraints.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!