SU-D-211-03: An Automated Inverse Planning Optimization Approach for Single- Fraction and Fractionated Radiosurgery Using Gamma Knife Perfexion

2012 ◽  
Vol 39 (6Part3) ◽  
pp. 3610-3610
Author(s):  
K Ghobadi ◽  
H Ghaffari ◽  
D Aleman ◽  
M Ruschin ◽  
D Jaffray
Keyword(s):  
Gamma Knife ◽  
Optimization Approach ◽  
Inverse Planning ◽  
Single Fraction ◽  
Planning Optimization ◽  
Gamma Knife Perfexion

In vitro biological dosimeter modeling of the glioblastoma response to radiation delivered by the Gamma Knife

2010 ◽  
Vol 113 (Special_Supplement) ◽  
pp. 222-227
Author(s):  
Ryan Smith ◽  
Kris A. Smith ◽  
Christopher A. Biggs ◽  
Adrienne C. Scheck
Keyword(s):  
Cell Line ◽  
Gamma Knife ◽  
Radiation Treatment ◽  
High Dose ◽  
Single Fraction ◽  
Fractionated Radiotherapy ◽  
Tissue Equivalent ◽  
Cell Subpopulations ◽  
Gamma Knife Perfexion

Object The goal of this study was to develop an assay that makes possible the assessment of the glioma cell response to single-fraction high-dose Gamma Knife surgery. In this assay, the isolation of radioresistant cell subpopulations facilitates mechanistic studies of radioresistance. Methods A tissue-equivalent paraffin phantom with an aperture capable of holding an Opticell cell culture cassette was developed for treatment with the Leksell Gamma Knife model C. A second apparatus, which the authors also created, uses the manufacturer-supplied polystyrene phantom, thereby allowing this assay to be performed in the Leksell Gamma Knife Perfexion. After treatment, the cells were morphologically assessed to determine their response to radiation treatment. Two specific parameters were used to determine radiosensitivity: 1) the diameter of the clearing zone, defined as the central region of cell death; and 2) the number of surviving colonies within this central high-dose clearing zone. Results Radioresistance was compared in 2 different cell lines from glioblastomas. The first cell line, ME, was established from a primary tumor before its treatment, and the second cell line, DIV, was established from a tumor that recurred after treatment with chemotherapy and fractionated radiotherapy. The ME cell line had the most robust response to radiosurgery, as characterized by a consistently larger clearing zone (28.33 ± 1.1 mm). In contrast, the clearing zone produced when the DIV cell line was used was 24.0 ± 1 mm, indicating an approximate response difference of 5 Gy. The mean number of surviving colonies within the clearing zone for the ME cell line was 1.33 ± 1 compared with that for the DIV cell line, which was 66.67 ± 2. Conclusions The authors developed a biological dosimeter to model the response of cells from glioblastomas to single-fraction high-dose radiation. This system also allows the identification and isolation of radioresistant cells.

scholarly journals Split Common Coincidence Point Problem: A Formulation Applicable to (Bio)Physically-Based Inverse Planning Optimization

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 2086
Author(s):  
Charles E. Chidume ◽  
Lois C. Okereke
Keyword(s):  
Optimization Problem ◽  
Coincidence Point ◽  
Point Problem ◽  
Optimization Approach ◽  
Inverse Planning ◽  
Clinical Criteria ◽  
Planning Optimization ◽  
Physically Based ◽  
Treatment Plans ◽  
Optimized Treatment

Inverse planning is a method of radiotherapy treatment planning where the care team begins with the desired dose distribution satisfying prescribed clinical objectives, and then determines the treatment parameters that will achieve it. The variety in symmetry, form, and characteristics of the objective functions describing clinical criteria requires a flexible optimization approach in order to obtain optimized treatment plans. Therefore, we introduce and discuss a nonlinear optimization formulation called the split common coincidence point problem (SCCPP). We show that the SCCPP is a suitable formulation for the inverse planning optimization problem with the flexibility of accommodating several biological and/or physical clinical objectives. Also, we propose an iterative algorithm for approximating the solution of the SCCPP, and using Bregman techniques, we establish that the proposed algorithm converges to a solution of the SCCPP and to an extremum of the inverse planning optimization problem. We end with a note on useful insights on implementing the algorithm in a clinical setting.

Stereotactic radiosurgery versus stereotactic radiotherapy for patients with vestibular schwannoma: a Leksell Gamma Knife Society 2000 debate

2000 ◽  
Vol 93 (supplement_3) ◽  
pp. 90-92 ◽  
Author(s):  
Mark E. Linskey
Keyword(s):  
Gamma Knife ◽  
Stereotactic Radiotherapy ◽  
Three Dimensional ◽  
Late Recurrence ◽  
Vestibular Schwannomas ◽  
Tumor Control ◽  
Complication Rates ◽  
Content Type ◽  
Single Fraction ◽  
Fine Print

✓ By definition, the term “radiosurgery” refers to the delivery of a therapeutic radiation dose in a single fraction, not simply the use of stereotaxy. Multiple-fraction delivery is better termed “stereotactic radiotherapy.” There are compelling radiobiological principles supporting the biological superiority of single-fraction radiation for achieving an optimal therapeutic response for the slowly proliferating, late-responding, tissue of a schwannoma. It is axiomatic that complication avoidance requires precise three-dimensional conformality between treatment and tumor volumes. This degree of conformality can only be achieved through complex multiisocenter planning. Alternative radiosurgery devices are generally limited to delivering one to four isocenters in a single treatment session. Although they can reproduce dose plans similar in conformality to early gamma knife dose plans by using a similar number of isocenters, they cannot reproduce the conformality of modern gamma knife plans based on magnetic resonance image—targeted localization and five to 30 isocenters. A disturbing trend is developing in which institutions without nongamma knife radiosurgery (GKS) centers are championing and/or shifting to hypofractionated stereotactic radiotherapy for vestibular schwannomas. This trend appears to be driven by a desire to reduce complication rates to compete with modern GKS results by using complex multiisocenter planning. Aggressive advertising and marketing from some of these centers even paradoxically suggests biological superiority of hypofractionation approaches over single-dose radiosurgery for vestibular schwannomas. At the same time these centers continue to use the term radiosurgery to describe their hypofractionated radiotherapy approach in an apparent effort to benefit from a GKS “halo effect.” It must be reemphasized that as neurosurgeons our primary duty is to achieve permanent tumor control for our patients and not to eliminate complications at the expense of potential late recurrence. The answer to minimizing complications while maintaining maximum tumor control is improved conformality of radiosurgery dose planning and not resorting to homeopathic radiosurgery doses or hypofractionation radiotherapy schemes.

scholarly journals Evaluating the impact of prescription isodose line on plan quality using Gamma Knife inverse planning

2021 ◽  
Author(s):  
Qianyi Xu ◽  
Gregory Kubicek ◽  
David Mulvihill ◽  
Warren Goldman ◽  
Gary Eastwick ◽  
...  
Keyword(s):  
Gamma Knife ◽  
Plan Quality ◽  
Inverse Planning ◽  
The Impact ◽  
Prescription Isodose

scholarly journals Intracranial Metastatic Neuroblastoma Treated with Gamma Knife Stereotactic Radiosurgery: Report of Two Novel Cases

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Nathan C. Rowland ◽  
Jennifer Andrews ◽  
Daxa Patel ◽  
David V. LaBorde ◽  
Adam Nowlan ◽  
...  
Keyword(s):  
Stereotactic Radiosurgery ◽  
Gamma Knife ◽  
Treatment Options ◽  
Tumor Burden ◽  
Poor Survival ◽  
Intracranial Metastasis ◽  
Temporary Reduction ◽  
Single Fraction ◽  
Curative Therapy ◽  
Gamma Knife Stereotactic Radiosurgery

Intracranial metastasis of neuroblastoma (IMN) is associated with poor survival. No curative therapy for the treatment of IMN currently exists. Unfractionated radiotherapy may be beneficial in the treatment of IMN given the known radiosensitivity of neuroblastoma as well as its proclivity to metastasize as discrete lesions. We present two patients with IMN treated with Gamma Knife stereotactic radiosurgery (SRS). Single-fraction radiotherapy yielded temporary reduction of tumor burden and stability of disease in both patients. SRS may be a useful palliative tool in the treatment of IMN and expands the overall treatment options for this disease.

PO-1908 Inverse planning in Gamma Knife radiotherapy for benign tumors

2021 ◽  
Vol 161 ◽  
pp. S1629
Author(s):  
M. Spaniol ◽  
S. Mai ◽  
T. Zakrzewski ◽  
M. Ehmann ◽  
F. Stieler
Keyword(s):  
Gamma Knife ◽  
Benign Tumors ◽  
Inverse Planning ◽  
Gamma Knife Radiotherapy

scholarly journals Verification of dose distribution on the gamma knife perfexion radiosurgery using gafchromic EBT3 film: RANDO phantom study

2020 ◽  
Vol 1528 ◽  
pp. 012028
Author(s):  
I N Pranditayana ◽  
A R. Setiadi ◽  
M M Ramadhan ◽  
D Tandian ◽  
S A. Pawiro
Keyword(s):  
Gamma Knife ◽  
Dose Distribution ◽  
Phantom Study ◽  
Gamma Knife Perfexion
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