Impact of 68Ga-DOTATOC PET/MRI on robotic radiosurgery treatment planning in meningioma patients: first experiences in a single institution.
Neurosurg Focus
; 46(6): E9, 2019 06 01.
Article
em En
| MEDLINE
| ID: mdl-31153151
ABSTRACT
OBJECTIVEFor stereotactic radiosurgery (SRS) planning, precise contouring of tumor boundaries and organs at risk is of utmost importance. Correct interpretation of standard neuroimaging (i.e., CT and MRI) can be challenging after previous surgeries or in cases of skull base lesions with complex shapes. The aim of this study was to evaluate the impact of 68Ga-DOTATOC PET/MRI on treatment planning for image-guided SRS by CyberKnife.METHODSThe authors retrospectively identified 11 meningioma treatments in 10 patients who received a 68Ga-DOTATOC PET/MRI prior to SRS. The planning target volume (PTV) used for the patients' treatment was defined as the reference standard. This was contoured by a treating radiosurgeon (RS0) using fused planning CT and PET/MRI data sets. The same tumors were then contoured by another experienced radiosurgeon (RS1) and by a less-experienced radiosurgeon (RS2), both blinded to PET data sets. A comparison of target volumes with focus on volume-based metrics and distance to critical structures was performed. RS1 and RS2 also filled in a questionnaire analyzing the confidence level and the subjective need for the implementation of PET data sets for contouring.RESULTSAnalysis showed a subjective personal preference for PET/MRI in all cases for both radiosurgeons, particularly in proximity to critical structures. The analysis of the planning volumes per physician showed significantly smaller RS2-PTV in comparison to RS1-PTV and to RS0-PTV, whereas the median volumes were comparable between RS1-PTV and RS2-PTV (median RS0 4.3 cm3 [IQR 3.4-6.5 cm3] and RS1 4.5 cm3 [IQR 2.7-6 cm3] vs RS2 2.6 cm3 [IQR 2-5 cm3]; p = 0.003). This was also reflected in the best spatial congruency between the 2 experienced physicians (RS0 and RS1). The percentage of the left-out volume contoured by RS1 and RS2 compared to RS0 with PET/MRI demonstrated a relevant left-out-volume portion in both cases with greater extent for the less-experienced radiosurgeon (RS2) (RS1 19.1% [IQR 8.5%-22%] vs RS2 40.2% [IQR 34.2%-53%]). No significant differences were detected regarding investigated critical structures.CONCLUSIONSThis study demonstrated a relevant impact of PET/MRI on target volume delineation of meningiomas. The extent was highly dependent on the experience of the treating physician. This preliminary study supports the relevance of 68Ga-DOTATOC PET/MRI as a tool for radiosurgical treatment planning of meningiomas.
Palavras-chave
68Ga-DOTATOC = gallium-68labeled [DOTA0-Phe1-Tyr3]octreotide; 68Ga-DOTATOC PET/MRI; CyberKnife; FSRT = fractionated stereotactic radiation therapy; GTV = gross tumor volume; IMRT = intensity-modulated radiotherapy; IQR = interquartile range; MP-RAGE = magnetization-prepared rapid acquisition with gradient echo; OAR = organ at risk; PET = positron emission tomography; PTV = planning target volume; RS = radiosurgeon; SRS = stereotactic radiosurgery; SSTR = somatostatin receptor; meningioma; stereotactic radiosurgery
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Compostos Organometálicos
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Cuidados Pré-Operatórios
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Imageamento por Ressonância Magnética
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Octreotida
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Irradiação Craniana
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Radiocirurgia
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Compostos Radiofarmacêuticos
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Tomografia por Emissão de Pósitrons
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Imagem Multimodal
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Procedimentos Cirúrgicos Robóticos
Tipo de estudo:
Observational_studies
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Qualitative_research
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Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Neurosurg Focus
Assunto da revista:
NEUROCIRURGIA
Ano de publicação:
2019
Tipo de documento:
Article