Dataset Information

Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

ABSTRACT: Stereotactic radiosurgery (SRS) is the accurate, conformal delivery of high-dose radiation to well-defined targets while minimizing normal structure doses via steep dose gradients. While inverse treatment planning (ITP) with computerized optimization algorithms are routine, many aspects of the planning process remain user-dependent. We performed an international, multi-institutional benchmark trial to study planning variability and to analyze preferable ITP practice for spinal robotic radiosurgery. 10 SRS treatment plans were generated for a complex-shaped spinal metastasis with 21 Gy in 3 fractions and tight constraints for spinal cord (V14Gy < 2 cc, V18Gy < 0.1 cc) and target (coverage > 95%). The resulting plans were rated on a scale from 1 to 4 (excellent-poor) in five categories (constraint compliance, optimization goals, low-dose regions, ITP complexity, and clinical acceptability) by a blinded review panel. Additionally, the plans were mathemati-cally rated based on plan indices (critical structure and target doses, conformity, monitor units, normal tissue complication probability, and treatment time) and compared to the human rankings. The treatment plans and the reviewers' rankings varied substantially among the participating centers. The average mean overall rank was 2.4 (1.2-4.0) and 8/10 plans were rated excellent in at least one category by at least one reviewer. The mathematical rankings agreed with the mean overall human rankings in 9/10 cases pointing toward the possibility for sole mathematical plan quality comparison. The final rankings revealed that a plan with a well-balanced trade-off among all planning objectives was preferred for treatment by most par-ticipants, reviewers, and the mathematical ranking system. Furthermore, this plan was generated with simple planning techniques. Our multi-institutional planning study found wide variability in ITP approaches for spinal robotic radiosurgery. The participants', reviewers', and mathematical match on preferable treatment plans and ITP techniques indicate that agreement on treatment planning and plan quality can be reached for spinal robotic radiosurgery.

SUBMITTER: Blanck O

PROVIDER: S-EPMC5690905 | biostudies-other | 2016 May

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

Blanck Oliver O Wang Lei L Baus Wolfgang W Grimm Jimm J Lacornerie Thomas T Nilsson Joakim J Luchkovskyi Sergii S Cano Isabel Palazon IP Shou Zhenyu Z Ayadi Myriam M Treuer Harald H Viard Romain R Siebert Frank-Andre FA Chan Mark K H MK Hildebrandt Guido G Dunst Jürgen J Imhoff Detlef D Wurster Stefan S Wolff Robert R Romanelli Pantaleo P Lartigau Eric E Semrau Robert R Soltys Scott G SG Schweikard Achim A

Journal of applied clinical medical physics 20160508 3

Stereotactic radiosurgery (SRS) is the accurate, conformal delivery of high-dose radiation to well-defined targets while minimizing normal structure doses via steep dose gradients. While inverse treatment planning (ITP) with computerized optimization algorithms are routine, many aspects of the planning process remain user-dependent. We performed an international, multi-institutional benchmark trial to study planning variability and to analyze preferable ITP practice for spinal robotic radiosurge ...[more]

PMID: 27167291

Similar Datasets

Project description:Large patient cohorts are necessary to validate the efficacy of transoral robotic surgery (TORS) in the management of head and neck cancer.To review oncologic outcomes of TORS from a large multi-institutional collaboration and to identify predictors of disease recurrence and disease-specific mortality.A retrospective review of records from 410 patients undergoing TORS for laryngeal and pharyngeal cancers from January 1, 2007, through December 31, 2012, was performed. Pertinent data were obtained from 11 participating medical institutions.Select patients received radiation therapy and/or chemotherapy before or after TORS.Locoregional control, disease-specific survival, and overall survival were calculated. We used Kaplan-Meier survival analysis with log-rank testing to evaluate individual variable association with these outcomes, followed by multivariate analysis with Cox proportional hazards regression modeling to identify independent predictors.Of the 410 patients treated with TORS in this study, 364 (88.8%) had oropharyngeal cancer. Of these 364 patients, information about post-operative adjuvant therapy was known about 338: 106 (31.3) received radiation therapy alone, and 72 (21.3%) received radiation therapy with concurrent chemotherapy. Neck dissection was performed in 323 patients (78.8%). Mean follow-up time was 20 months. Local, regional, and distant recurrence occurred in 18 (4.4%), 15 (3.7%), and 10 (2.4%) of 410 patients, respectively. Seventeen (4.1%) died of disease, and 13 (3.2%) died of other causes. The 2-year locoregional control rate was 91.8% (95% CI, 87.6%-94.7%), disease-specific survival 94.5% (95% CI, 90.6%-96.8%), and overall survival 91% (95% CI, 86.5%-94.0%). Multivariate analysis identified improved survival among women (P = .05) and for patients with tumors arising in tonsil (P = .01). Smoking was associated with worse overall all-cause mortality (P = .01). Although advanced age and tobacco use were associated with locoregional recurrence and disease-specific survival, they, as well as tumor stage and other adverse histopathologic features, did not remain significant on multivariate analysis.This large, multi-institutional study supports the role of TORS within the multidisciplinary treatment paradigm for the treatment of head and neck cancer, especially for patients with oropharyngeal cancer. Favorable oncologic outcomes have been found across institutions. Ongoing comparative clinical trials funded by the National Cancer Institute will further evaluate the role of robotic surgery for patients with head and neck cancers.

Project description:Objectives The purposes of this study are to assess the effectiveness of CyberKnife® stereotactic radiosurgery (SRS) in providing both initial and sustained pain relief for patients with both forms of trigeminal neuralgia (TN), assess potential prognostic factors, and examine treatment-related toxicities. Methods The RSSearch(®) Patient Registry was screened for TN cases from July 2007 to June 2015. We evaluated initial pain relief achieved by examining changes in the Visual Analog Scale (VAS) scores following SRS. Prognostic factors relating to initial pain relief and the relationship between maximum dose (Dmax) and toxicity incidence were analyzed via univariate logistic regressions. We evaluated prognostic factors relating to sustained pain relief using the Kaplan-Meier method and log-rank analysis. Results Our analysis included 125 TN1 patients and 38 TN2 patients with initial VAS scores ? 3 treated at 16 community radiotherapy centers. Median Dmax for both cohorts was 75 Gy with a larger range for TN1 cases (67.42 Gy - 110.29 Gy) as compared to TN2 cases (70.00 Gy - 78.48 Gy). At initial follow-up, mean VAS scores after SRS were significantly lower for TN1 and TN2 patients (p < 0.0001). The vast majority of TN1 (87.2%) and TN2 (86.8%) patients experienced initial pain relief. Higher initial VAS scores (p = 0.015) were correlated with a greater likelihood of initial treatment success for TN1 patients. We did not identify any treatment or patient characteristics that had significant effects on initial pain relief for TN2 patients. Of the TN1 cohort, 28 of 125 patients reported follow-ups one year or greater after SRS. Twenty-three of 28 TN1 patients (82%) reported VAS scores of 1 or less at one-year follow-up, and eight of 11 patients (72%) had VAS scores of 1 or less at the two-year follow-up. No potential prognostic factors for long-term pain relief were significant. Roughly 18% and 11% of TN1 and TN2 patients, respectively, experienced acute toxicities (all RTOG Grade 1 or 2), with the most common being sensory neuropathy, generalized pain, and nausea. Dmax > 75 Gy was not a predictor of toxicity incidence in TN1 cases (p = 0.597) but was significant for TN2 patients (p = 0.0009 following Fisher's exact test). Conclusions SRS is an effective treatment option for TN patients in community settings. Initial pain relief following SRS was achieved in a vast majority of TN patients with associated minor toxicities observed in less than 20% of all patients.

Project description:As irradiated brain volume at 12 Gy (V12) is a predictor for radionecrosis, the purpose of the study was to develop a model for Cyberknife (CK) plans that is able to predict the lowest achievable V12 at a given tumor size and prescription dose (PD), and to suggest a new quality index regarding V12 for optimizing the treatment planning of brain metastases.In our model V12 was approximated as a spherical shell around the tumor volume. The radial distance between tumor surface and the 12 Gy isodose line was calculated using an approximation of the mean dose gradient in that area. Assuming a radially symmetrical irradiation from the upper half space, the dose distribution is given by the superposition of single fields. The dose profiles of a single field were derived by the measured off-center ratios (OCR) of the CK system. Using the calculated gradients of the sum dose profiles, minimal-V12 was estimated for different tumor sizes. The model calculation was tested using a phantom dataset and retrospectively applied on clinical cases.Our model allows the prediction of a best-case scenario for V12 at a given tumor size and PD which was confirmed by the results of the isocentric phantom plans. The results of the non-isocentric phantom plans showed that an optimization of coverage caused an increase in V12. This was in accordance with the results of the retrospective analysis. V12 s of the clinical cases were on average twice that of the predicted model calculation. A good agreement was achieved for plans with an optimal conformity index (nCI). Re-planning of cases with high V12 showed that lower values could be reached by selecting smaller collimators and by allowing a larger number of total MU and more MU per beam.V12 is a main parameter for assessing plan quality in terms of radiotoxicity. The index f12 defined as the ratio of V12 from the actual plan with the evaluated V12 from our model describes the conformity of an optimally possible V12 and thus can be used as a new quality index for optimizing treatment plans.

Project description:One third of all cancer patients will develop bone metastases and the vertebral column is involved in approximately 70% of these patients. Conventional radiotherapy with of 1-10 fractions and total doses of 8-30?Gy is the current standard for painful vertebral metastases; however, the median pain response is short with 3-6 months and local tumor control is limited with these rather low irradiation doses. Recent advances in radiotherapy technology - intensity modulated radiotherapy for generation of highly conformal dose distributions and image-guidance for precise treatment delivery - have made dose-escalated radiosurgery of spinal metastases possible and early results of pain and local tumor control are promising. The current study will investigate efficacy and safety of radiosurgery for painful vertebral metastases and three characteristics will distinguish this study. 1) A prognostic score for overall survival will be used for selection of patients with longer life expectancy to allow for analysis of long-term efficacy and safety. 2) Fractionated radiosurgery will be performed with the number of treatment fractions adjusted to either good (10 fractions) or intermediate (5 fractions) life expectancy. Fractionation will allow inclusion of tumors immediately abutting the spinal cord due to higher biological effective doses at the tumor - spinal cord interface compared to single fraction treatment. 3) Dose intensification will be performed in the involved parts of the vertebrae only, while uninvolved parts are treated with conventional doses using the simultaneous integrated boost concept.It is the study hypothesis that hypo-fractionated image-guided radiosurgery significantly improves pain relief compared to historic data of conventionally fractionated radiotherapy. Primary endpoint is pain response 3 months after radiosurgery, which is defined as pain reduction of ??2 points at the treated vertebral site on the 0 to 10 Visual Analogue Scale. 60 patients will be included into this two-centre phase II trial.Results of this study will refine the methods of patient selection, target volume definition, treatment planning and delivery as well as quality assurance for radiosurgery. It is the intention of this study to form the basis for a future randomized controlled trial comparing conventional radiotherapy with fractionated radiosurgery for palliation of painful vertebral metastases.ClinicalTrials.gov Identifier: NCT01594892.

Project description:We hypothesized that use of a true 3D display providing easy visualization of patient anatomy and dose distribution would lead to the production of better quality radiation therapy treatment plans. We report on a randomized prospective multi-institutional study to evaluate a novel 3D display for treatment planning.The Perspecta Spatial 3D System produces 360 degrees holograms by projecting crosssectional images on a diffuser screen rotating at 900 rpm. Specially-developed software allows bi-directional transfer of image and dose data between Perspecta and the Pinnacle planning system.Thirty-three patients previously treated at three institutions were included in this IRB-approved study. Patient data were de-identified, randomized, and assigned to different planners. A physician at each institution reviewed the cases and established planning objectives. Two treatment plans were then produced for each patient, one based on the Pinnacle system alone and another in conjunction with Perspecta. Plan quality was then evaluated by the same physicians who established the planning objectives. All plans were viewable on both Perspecta and Pinnacle for review. Reviewing physicians were blinded to the planning device used. Data from a 13-patient pilot study were also included in the analysis.Perspecta plans were considered better in 28 patients (61%), Pinnacle in 14 patients (30%), and both were equivalent in 4 patients. The use of non-coplanar beams was more common with Perspecta plans (82% vs. 27%). The mean target dose differed by less than 2% between rival plans. Perspecta plans were somewhat more likely to have the hot spot located inside the target (43% vs. 33%). Conversely, 30% of the Pinnacle plans had the hot spot outside the target compared with 18% for Perspecta plans. About 57% of normal organs received less dose from Perspecta plans. No statistically significant association was found between plan preference and planning institution or planner.The study found that use of the holographic display leads to radiotherapy plans preferred in a majority of cases over those developed with 2D displays. These data indicate that continued development of this technology for clinical implementation is warranted.

Dataset Information

Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

Publications

Inverse treatment planning for spinal robotic radiosurgery: an international multi-institutional benchmark trial.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets