A geometrically based method for automated radiosurgery planning

Wagner, Thomas H.; Yi, Taeil; Meeks, Sanford L.; Bova, Francis J.; Brechner, Beverly L.; Chen, Yunmei; Buatti, John M.; Friedman, William A.; Foote, Kelly D.; Bouchet, Lionel G.

doi:10.1016/s0360-3016(00)00790-2

Cited by 42 publications

(34 citation statements)

References 14 publications

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“…The collimator size largely depends on the size of the target. Complex targets will require a combination of large collimators to fi ll in the bulk of the tumor with dose, and smaller collimators to infuse the intricate, smaller aspects of the structure [ 9 ]. For SBRT in which IMRT based delivery techniques are used, minimizing the number of beams and the number of control points per beam will lead to faster delivery times.…”

Section: Treatment Delivery Timementioning

confidence: 99%

Planning and Dosimetry for Stereotactic Body Radiotherapy

Dieterich

2014

Stereotactic Body Radiotherapy

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Planning for SBRT is characterized by the need to create high dose gradients from target to critical structures in the vicinity. Since SBRT is a relatively new fi eld, appropriate DVH constraints are still under development in clinical trials and single-center studies.The effect of residual motion such as deformation, rotation and residual respiratory motion has to be considered to determine appropriate ITV and PTV margins. SBRT targets such as lung are located in areas of the body with large tissue inhomogeneities. Treatment algorithms must be capable of modeling these inhomogeneities appropriately to generate a dose calculation which is close to the delivered dose. Planner skill has traditionally played a large role in designing high quality treatment plans with optimum target coverage and tissue sparing. Data mining of existing plans and the use of plan libraries is being explored to aid the treatment planner in standardizing planning approaches to more consistently fi nd the optimum dose distribution. To ensure a close match between plan dose calculations and delivered dose calculations, the dosimetry of small fi elds must be well understood and modelled in the treatment planning system. The small fi elds and sharp dose gradients pose more stringent challenges for patient-specifi c SBRT QA. Keywords IntroductionTreatment planning for stereotactic radiosurgery is very diverse in that it can range from using the same planning techniques as conventional IMRT (Intensity Modulated Radiation Therapy) with the only difference being in the dose-fractionation scheme and the technical constraints of delivery, to

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Section: Treatment Delivery Timementioning

confidence: 99%

Planning and Dosimetry for Stereotactic Body Radiotherapy

Dieterich

2014

Stereotactic Body Radiotherapy

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“…In this procedure a virtual wall ( Figure 11) is placed orthogonal to the axis, just next to the target, in order to prevent the surgeon from moving the instrument beyond this point; N multiple target positioning, in which the former procedure is repeated at several different positions along the translation axis: a virtual wall ( Figure 12) is placed next to each target position. When using the PRS, this procedure allows delivery of different X-ray doses at different positions so as to treat non-spherical tumours, which is not possible when manual insertion of the probe is performed (19,20) ; N continuous path positioning, which consists of moving the tool along the linear path in accordance with a pre-planned trajectory in time. In this case a time-varying bilateral virtual wall needs to be generated, so as to guide the surgeon along the path (Figure 13).…”

Section: Master-slave Haptic Controlmentioning

confidence: 99%

A telerobotic haptic system for minimally invasive stereotactic neurosurgery

Rossi¹,

Trevisani²,

Zannotto³

2005

IJMRCAS

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Medical robotics and computer assisted surgery are feasible and promising applications of robotic technology, whose main goals are surgical augmentation, information enhancement and improved surgical action. Neurosurgery probably presents the most major challenges, and can considerably benefit from the introduction of computers and robots to guide surgical procedures. This paper presents an innovative masterslave haptic robotic system for minimally invasive neurosurgery, which can help surgeons overcome human shortcomings and perform more accurate, repeatable, and reliable stereotactic neurosurgery. The system, named LANS, consists of a slave mechatronic actuator and a haptic master. The slave is designed to move linearly a laser pointer, a biopsy needle or a low-energy X-ray emitter along a pre-planned axis. The tool insertion into the brain is guided by the surgeon through the haptic master which also provides force feedback to the operator. Not only can the haptic master reproduce the contact force between the surgical tool and the treated tissue, but it can also produce virtual forces aimed at assisting surgeons during the operations. Experiments have been conducted to prove the soundness and accuracy of the overall system mechanical design and to assess the effectiveness of the control schemes synthesized for the master and the slave.

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“…15 To address this issue, a sequential planning strategy has been employed by most of the existing GK inverse planning algorithms, including the inverse planning algorithm provided in the prevailing commercial treatment planning system for the Leksell GK units, named Leksell GammaPlan (LGP, Elekta Instrument AB Stockholm, Stockholm, Sweden). 11,13,14,[16][17][18][19] Specifically, isocenter locations are predetermined using a grassfire and sphere-packing (GSP) algorithm or some other geometric methods based on the geometry of the treatment targets. 13,16,18 Then, the shot shapes and durations are optimized at these predetermined locations to achieve a good dose distribution.…”

Section: Introductionmentioning

confidence: 99%

A preliminary study on a multiresolution‐level inverse planning approach for Gamma Knife radiosurgery

et al. 2020

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Purpose: With many plan variables to determine, manual forward planning for Gamma Knife (GK) radiosurgery is very challenging. Inverse planning eases GK planning by determining the variables via solving an optimization problem. However, due to the vast search space, most inverse planning algorithms, including the one provided in Leksell GammaPlan (LGP) treatment planning system, have to predetermine the isocenter locations using some geometric methods and then optimize the shot shapes and durations at these preselected isocenters. This sequential planning scheme does not necessarily lead to optimal isocenter locations and hence globally optimal plans. In this study, we proposed a multiresolution-level (MRL) inverse planning approach, attempting to approach this large-scale GK optimization problem via an iterative method. Methods: In our MRL approach, several rounds of optimizations were performed with a progressively increased resolution used for isocenter candidates. At each round, an optimization problem was solved to optimize the beam-on time for each collimator and sector at each isocenter candidate. The isocenters that obtained nonzero beam-on times at the previous round and their neighbors on a finer resolution were used as new isocenter candidates for the next round of optimization. After plan optimization, shot sequencing was performed to group the optimized sectors to deliverable composite shots. Results: We have tested our MRL approach on six GK cases previously treated in our institution. For the five cases that have a single target, with similar target coverage obtained, our MRL inverse planning approach achieved better plan quality compared to manual forward planning and LGP inverse planning, with higher selectivity (0.73 AE 0.07 vs 0.72 AE 0.08 and 0.62 AE 0.10), lower gradient index (2.71 AE 0.25 vs 2.78 AE 0.24 and 3.00 AE 0.29), lower brainstem D 0.1cc dose (6.10 AE 4.46 Gy vs 8.87 AE 4.82 Gy and 9.17 AE 3.80 Gy), and shorter total beam-on time (62.1 AE 22.9 min vs 83.6 AE 28.2 min and 70.7 AE 16.7 min). For the case that have six targets, compared with manual planning and LGP inverse planning, our MRL approach achieved higher selectivity (0.68 vs 0.57 and 0.47) and lower gradient index (3.77 vs 4.51 and 5.11). The beam-on time of our plan was slightly longer than manual planning and LGP inverse planning (206.4 min vs 204.7 min and 199.3 min). We have also performed sector duration optimization at the isocenters determined by manual planning or the LGP inverse planning, and the resulting plan qualities were found to be inferior to our MRL approach for all the six cases. Conclusions: This preliminary study has demonstrated the efficacy and feasibility of our MRL inverse planning approach for GK radiosurgery.

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A geometrically based method for automated radiosurgery planning

Cited by 42 publications

References 14 publications

Planning and Dosimetry for Stereotactic Body Radiotherapy

Planning and Dosimetry for Stereotactic Body Radiotherapy

A telerobotic haptic system for minimally invasive stereotactic neurosurgery

A preliminary study on a multiresolution‐level inverse planning approach for Gamma Knife radiosurgery

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