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1.
Strahlenther Onkol ; 196(5): 421-443, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32211939

RESUMO

This review details and discusses the technological quality requirements to ensure the desired quality for stereotactic radiotherapy using photon external beam radiotherapy as defined by the DEGRO Working Group Radiosurgery and Stereotactic Radiotherapy and the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The covered aspects of this review are 1) imaging for target volume definition, 2) patient positioning and target volume localization, 3) motion management, 4) collimation of the irradiation and beam directions, 5) dose calculation, 6) treatment unit accuracy, and 7) dedicated quality assurance measures. For each part, an expert review for current state-of-the-art techniques and their particular technological quality requirement to reach the necessary accuracy for stereotactic radiotherapy divided into intracranial stereotactic radiosurgery in one single fraction (SRS), intracranial fractionated stereotactic radiotherapy (FSRT), and extracranial stereotactic body radiotherapy (SBRT) is presented. All recommendations and suggestions for all mentioned aspects of stereotactic radiotherapy are formulated and related uncertainties and potential sources of error discussed. Additionally, further research and development needs in terms of insufficient data and unsolved problems for stereotactic radiotherapy are identified, which will serve as a basis for the future assignments of the DGMP Working Group for Physics and Technology in Stereotactic Radiotherapy. The review was group peer-reviewed, and consensus was obtained through multiple working group meetings.


Assuntos
Consenso , Garantia da Qualidade dos Cuidados de Saúde/normas , Radiocirurgia/normas , Alemanha , Doses de Radiação , Sociedades Médicas
2.
Strahlenther Onkol ; 194(9): 843-854, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29802435

RESUMO

PURPOSE: To investigate the quality of treatment plans of spinal radiosurgery derived from different planning and delivery systems. The comparisons include robotic delivery and intensity modulated arc therapy (IMAT) approaches. Multiple centers with equal systems were used to reduce a bias based on individual's planning abilities. The study used a series of three complex spine lesions to maximize the difference in plan quality among the various approaches. METHODS: Internationally recognized experts in the field of treatment planning and spinal radiosurgery from 12 centers with various treatment planning systems participated. For a complex spinal lesion, the results were compared against a previously published benchmark plan derived for CyberKnife radiosurgery (CKRS) using circular cones only. For two additional cases, one with multiple small lesions infiltrating three vertebrae and a single vertebra lesion treated with integrated boost, the results were compared against a benchmark plan generated using a best practice guideline for CKRS. All plans were rated based on a previously established ranking system. RESULTS: All 12 centers could reach equality (n = 4) or outperform (n = 8) the benchmark plan. For the multiple lesions and the single vertebra lesion plan only 5 and 3 of the 12 centers, respectively, reached equality or outperformed the best practice benchmark plan. However, the absolute differences in target and critical structure dosimetry were small and strongly planner-dependent rather than system-dependent. Overall, gantry-based IMAT with simple planning techniques (two coplanar arcs) produced faster treatments and significantly outperformed static gantry intensity modulated radiation therapy (IMRT) and multileaf collimator (MLC) or non-MLC CKRS treatment plan quality regardless of the system (mean rank out of 4 was 1.2 vs. 3.1, p = 0.002). CONCLUSIONS: High plan quality for complex spinal radiosurgery was achieved among all systems and all participating centers in this planning challenge. This study concludes that simple IMAT techniques can generate significantly better plan quality compared to previous established CKRS benchmarks.


Assuntos
Benchmarking , Radiocirurgia/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos , Neoplasias da Coluna Vertebral , Vértebras Torácicas , Idoso , Algoritmos , Fracionamento da Dose de Radiação , Humanos , Recidiva Local de Neoplasia/radioterapia , Órgãos em Risco , Radiocirurgia/instrumentação , Dosagem Radioterapêutica , Radioterapia de Intensidade Modulada/instrumentação , Reirradiação , Procedimentos Cirúrgicos Robóticos/instrumentação , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/secundário , Vértebras Torácicas/cirurgia
3.
Strahlenther Onkol ; 190(11): 1066-74, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25060175

RESUMO

PURPOSE: This study compares the quality of intensity-modulated radiotherapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans optimized for an Elekta Agility(TM) (Elekta, Stockholm, Sweden) multileaf collimator (MLC; leaf width 5 mm) and an Elekta MLCi2 (leaf width 10 mm) for complex target volumes (anal, AC; head and neck, H&N and prostate cancer, PC). PATIENTS AND METHODS: For plan comparisons, 15 patients who had been treated with IMRT or VMAT using the MLCi2 were selected. For each patient, a retrospective treatment plan using the MLCi2 for the technique not applied was created, as were treatment plans for both techniques using the Agility(TM) MLC. Dose-volume histograms (DHVs) for planning target volumes (PTVs) and organs at risk (OARs) were compared. Further parameters relating to dose conformity, dose homogeneity and mean dose (Dmean) to the PTV, compliance with the intended OAR dose criteria and overall dose to normal tissue were analyzed. Verification measurements were performed and optimization and treatment times were compared. RESULTS: Compared to the MLCi2 plans, the Agility(TM) IMRT and VMAT plans show better or equivalent results in terms of PTV dose conformity and homogeneity. Compliance with the intended OAR dose criteria does not differ according to technique or MLC type. Slight differences are shown for dose distributions in OARs and normal tissue. Verification measurements show that all plans fulfill the acceptance criteria of a minimum of 95 % matched dose points for the 3 %/3 mm γ criterion. Optimization times for the VMAT plans increase compared to the IMRT plans, whereas treatment times decrease. CONCLUSION: With the MLCi2, treatment of complex target volumes with VMAT was only possible with compromises in terms of target coverage. Using the Agility(TM) MLC, even complex target volumes can be treated with VMAT without compromising target coverage or resulting in higher exposure of OARs or normal tissue.


Assuntos
Neoplasias/radioterapia , Planejamento da Radioterapia Assistida por Computador/instrumentação , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade , Resultado do Tratamento
4.
Int J Radiat Oncol Biol Phys ; 113(1): 214-227, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35074434

RESUMO

PURPOSE: Our purpose was to investigate whether liver stereotactic body radiation therapy treatment planning can be harmonized across different treatment planning systems, delivery techniques, and institutions by using a specific prescription method and to minimize the knowledge gap concerning intersystem and interuser differences. We provide best practice guidelines for all used techniques. METHODS AND MATERIALS: A multiparametric specification of target dose (gross target volume [GTV]D50%, GTVD0.1cc, GTVV90%, planning target volume [PTV]V70%) with a prescription dose of GTVD50% = 3 × 20 Gy and organ-at-risk (OAR) limits were distributed with computed tomography and structure sets from 3 patients with liver metastases. Thirty-five institutions provided 132 treatment plans using different irradiation techniques. These plans were first analyzed for target and OAR doses. Four different renormalization methods were performed (PTVDmin, PTVD98%, PTVD2%, PTVDmax). The resulting 660 treatments plans were evaluated regarding target doses to study the effect of dose renormalization to different prescription methods. A relative scoring system was used for comparisons. RESULTS: GTVD50% prescription can be performed in all systems. Treatment plan harmonization was overall successful, with standard deviations for Dmax, PTVD98%, GTVD98%, and PTVDmean of 1.6, 3.3, 1.9, and 1.5 Gy, respectively. Primary analysis showed 55 major deviations from clinical goals in 132 plans, whereas in only <20% of deviations GTV/PTV dose was traded for meeting OAR limits. GTVD50% prescription produced the smallest deviation from target planning objectives and between techniques, followed by the PTVDmax, PTVD98%, PTVD2%, and PTVDmin prescription. Deviations were significant for all combinations but for the PTVDmax prescription compared with GTVD50% and PTVD98%. Based on the various dose prescription methods, all systems significantly differed from each other, whereas GTVD50% and PTVD98% prescription showed the least difference between the systems. CONCLUSIONS: This study showed the feasibility of harmonizing liver stereotactic body radiation therapy treatment plans across different treatment planning systems and delivery techniques when a sufficient set of clinical goals is given.


Assuntos
Neoplasias Hepáticas , Radiocirurgia , Radioterapia de Intensidade Modulada , Benchmarking , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/radioterapia , Radiocirurgia/métodos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador/métodos , Radioterapia de Intensidade Modulada/métodos
5.
Head Neck ; 41(4): E48-E54, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30521102

RESUMO

BACKGROUND: For locally recurrent head and neck cancer, re-irradiation with modern techniques like stereotactic body radiotherapy is a promising, possibly curative alternative to palliative systemic therapy. METHODS: We report on 1 patient with nasopharyngeal carcinoma (NPC) and 1 patient with cutaneous squamous cell carcinoma (SCC). Both patients received full dose primary treatment (>66 Gy, EQD2), full dose re-irradiation (>50 Gy, EQD2), and a second course of re-irradiation via robotic radiosurgery (CyberKnife) for a second local recurrence. RESULTS: Both treatments resulted in adequate tumor response. No grade III-IV acute or late toxicities occurred. Follow-up at 6 months after third irradiation showed partial remission for the patient with NPC. In the second case (SCC), no toxicities occurred and the tumor was in remission 18 months after last treatment. CONCLUSION: These cases show that a second course of re-irradiation utilizing modern techniques like robotic radiosurgery might be feasible for carefully selected patients with head and neck cancer.


Assuntos
Carcinoma de Células Escamosas/radioterapia , Neoplasias de Cabeça e Pescoço/radioterapia , Recidiva Local de Neoplasia/radioterapia , Radioterapia Conformacional/métodos , Reirradiação/métodos , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/diagnóstico por imagem , Carcinoma de Células Escamosas/patologia , Relação Dose-Resposta à Radiação , Epistaxe/diagnóstico , Epistaxe/etiologia , Seguimentos , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Invasividade Neoplásica/patologia , Recidiva Local de Neoplasia/diagnóstico por imagem , Estadiamento de Neoplasias , Dosagem Radioterapêutica , Medição de Risco , Terapia de Salvação/métodos , Resultado do Tratamento
6.
Melanoma Res ; 29(2): 187-195, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30802230

RESUMO

The aim was to evaluate toxicity and oncological outcome of combined stereotactic radiosurgery (SRS) and immunotherapy or targeted therapy in patients with multiple brain metastases originating from malignant melanoma. Despite the fact that both SRS and kinase inhibitors or immune checkpoint inhibitors are considered standard treatment options for this indication, the optimal combination and sequence of these modalities remains largely unknown, especially for patients with a high number of brain metastases. For this retrospective analysis, conducted in two large SRS dedicated centers, we identified patients with brain metastases from malignant melanoma and simultaneous application of immunotherapy or targeted therapy within 30 days of SRS. Forty-eight patients with a total of 250 lesions (median: 3) were treated in 65 single fraction SRS sessions from 2012 to 2018. After a median follow-up of 8.3 months (range: 1.2-43.6 months), the 6-month and 1-year overall survival rates were 75.3 and 50.8%, respectively. The local control rate at one year was 89.5%. Immunotherapy and the application of systemic treatment directly before or concomitant to SRS were both associated with improved overall survival (P=0.037 and 0.045, respectively). We observed four grade III toxicities, of which only two can be clearly attributed to the combined treatment. Various combinations of SRS and kinase inhibitors or immune checkpoint inhibitors appear feasible and provide promising oncological results and safety profiles for treating few (n=1-4) and also multiple (n≥5) melanoma brain metastases.


Assuntos
Neoplasias Encefálicas/secundário , Imunoterapia/métodos , Melanoma/radioterapia , Melanoma/cirurgia , Inibidores de Proteínas Quinases/uso terapêutico , Radiocirurgia/métodos , Neoplasias Cutâneas/radioterapia , Neoplasias Cutâneas/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Encefálicas/patologia , Feminino , Humanos , Masculino , Melanoma/patologia , Pessoa de Meia-Idade , Inibidores de Proteínas Quinases/farmacologia , Estudos Retrospectivos , Neoplasias Cutâneas/patologia
7.
PLoS One ; 13(6): e0198692, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29874299

RESUMO

PURPOSE: Stereotactic radiosurgery (SRS) is an established primary treatment for newly diagnosed brain metastases with high local control rates. However, data about local re-irradiation in case of local failure after SRS (re-SRS) are rare. We evaluated the feasibility, efficacy and patient selection characteristics in treating locally recurrent metastases with a second course of SRS. METHODS: We retrospectively evaluated patients with brain metastases treated with re-SRS for local tumor progression between 2011 and 2017. Patient and treatment characteristics as well as rates of tumor control, survival and toxicity were analyzed. RESULTS: Overall, 32 locally recurrent brain metastases in 31 patients were irradiated with re-SRS. Median age at re-SRS was 64.9 years. The primary histology was breast cancer and non-small-cellular lung cancer (NSCLC) in respectively 10 cases (31.3%), in 5 cases malignant melanoma (15.6%). In the first SRS-course 19 metastases (59.4%) and in the re-SRS-course 29 metastases (90.6%) were treated with CyberKnife® and the others with Gamma Knife. Median planning target volume (PTV) for re-SRS was 2.5 cm3 (range, 0.1-37.5 cm3) and median dose prescribed to the PTV was 19 Gy (range, 12-28 Gy) in 1-5 fractions to the median 69% isodose (range, 53-80%). The 1-year overall survival rate was 61.7% and the 1-year local control rate was 79.5%. The overall rate of radiological radio-necrosis was 16.1% and four patients (12.9%) experienced grade ≥ 3 toxicities. CONCLUSIONS: A second course of SRS for locally recurrent brain metastases after prior local SRS appears to be feasible with acceptable toxicity and can be considered as salvage treatment option for selected patients with high performance status. Furthermore, this is the first study utilizing robotic radiosurgery for this indication, as an additional option for frameless fractionated treatment.


Assuntos
Neoplasias Encefálicas/radioterapia , Recidiva Local de Neoplasia/radioterapia , Lesões por Radiação/epidemiologia , Radiocirurgia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Encéfalo/efeitos da radiação , Neoplasias Encefálicas/mortalidade , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/secundário , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Carcinoma Pulmonar de Células não Pequenas/secundário , Estudos de Viabilidade , Feminino , Seguimentos , Humanos , Neoplasias Pulmonares/patologia , Imageamento por Ressonância Magnética , Masculino , Melanoma/mortalidade , Melanoma/patologia , Melanoma/radioterapia , Melanoma/secundário , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/secundário , Seleção de Pacientes , Lesões por Radiação/etiologia , Radiocirurgia/efeitos adversos , Radiocirurgia/instrumentação , Retratamento/efeitos adversos , Retratamento/métodos , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/efeitos adversos , Procedimentos Cirúrgicos Robóticos/instrumentação , Análise de Sobrevida , Resultado do Tratamento
8.
Phys Med ; 32(6): 838-46, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27245301

RESUMO

PURPOSE: High precision radiosurgery demands comprehensive delivery-quality-assurance techniques. The use of a liquid-filled ion-chamber-array for robotic-radiosurgery delivery-quality-assurance was investigated and validated using several test scenarios and routine patient plans. METHODS AND MATERIAL: Preliminary evaluation consisted of beam profile validation and analysis of source-detector-distance and beam-incidence-angle response dependence. The delivery-quality-assurance analysis is performed in four steps: (1) Array-to-plan registration, (2) Evaluation with standard Gamma-Index criteria (local-dose-difference⩽2%, distance-to-agreement⩽2mm, pass-rate⩾90%), (3) Dose profile alignment and dose distribution shift until maximum pass-rate is found, and (4) Final evaluation with 1mm distance-to-agreement criterion. Test scenarios consisted of intended phantom misalignments, dose miscalibrations, and undelivered Monitor Units. Preliminary method validation was performed on 55 clinical plans in five institutions. RESULTS: The 1000SRS profile measurements showed sufficient agreement compared with a microDiamond detector for all collimator sizes. The relative response changes can be up to 2.2% per 10cm source-detector-distance change, but remains within 1% for the clinically relevant source-detector-distance range. Planned and measured dose under different beam-incidence-angles showed deviations below 1% for angles between 0° and 80°. Small-intended errors were detected by 1mm distance-to-agreement criterion while 2mm criteria failed to reveal some of these deviations. All analyzed delivery-quality-assurance clinical patient plans were within our tight tolerance criteria. CONCLUSION: We demonstrated that a high-resolution liquid-filled ion-chamber-array can be suitable for robotic radiosurgery delivery-quality-assurance and that small errors can be detected with tight distance-to-agreement criterion. Further improvement may come from beam specific correction for incidence angle and source-detector-distance response.


Assuntos
Garantia da Qualidade dos Cuidados de Saúde , Radiometria/instrumentação , Radiocirurgia/instrumentação , Robótica , Humanos , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador
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