The current standards in radiotherapy of high-grade gliomas(HGG) are based on anatomic imaging techniques, usually computed tomography(CT) scanning and magnetic resonance imaging(MRI). The guidelines vary depending on...The current standards in radiotherapy of high-grade gliomas(HGG) are based on anatomic imaging techniques, usually computed tomography(CT) scanning and magnetic resonance imaging(MRI). The guidelines vary depending on whether the HGG is a histological grade 3 anaplastic glioma(AG) or a grade 4 glioblastoma multiforme(GBM). For AG, T2-weighted MRI sequences plus the region of contrast enhancement in T1 are considered for the delineation of the gross tumor volume(GTV), and an isotropic expansion of 15 to 20 mm is recommended for the clinical target volume(CTV). For GBM, the Radiation Therapy Oncology Group favors a two-step technique, with an initial phase(CTV1) including any T2 hyperintensity area(edema) plus a 20 mm margin treated with up to 46 Gy in 23 fractions, followed by a reduction in CTV2 to the contrast enhancement region in T1 with an additional 25 mm margin. The European Organisation of Research and Treatment of Cancer recommends a single-phase technique with a unique GTV, which comprises the T1 contrast enhancement region plus a margin of 20 to 30 mm. A total dose of 60 Gy in 30 fractions is usually delivered for GBM, and a dose of 59.4 Gy in 33 fractions is typically given for AG. As more than 85% of HGGs recur in field, dose-escalation studies have shown that 70 to 75 Gy can be delivered in 6 weeks with relevant toxicities developing in < 10% of the patients. However, the only randomized dose-escalation trial, in which the boost dose was guided by conventional MRI, did not show any survival advantage of this treatment over the reference arm. HGGs are amongst the most infiltrative and heterogeneous tumors, and it was hypothesized that the most highly aggressive areas were missed; thus, better visualization of these high-risk regions for radiation boost could decrease the recurrence rate. Innovations in imaging and linear accelerators(LINAC) could help deliver the right doses of radiation to the right subvolumes according to the dose-painting concept. Advanced imaging techniques provide functional info展开更多
目的根据肿瘤实质区及瘤周水肿区代谢物的差异,评估磁共振波谱成像对鉴别高级别胶质瘤与单发性颅内转移瘤的价值。方法经手术病理证实的高级别脑胶质瘤23例及单发脑转移瘤15例,术前均行常规MRI及1H-M RS检查。检测肿瘤实质区、瘤周水肿...目的根据肿瘤实质区及瘤周水肿区代谢物的差异,评估磁共振波谱成像对鉴别高级别胶质瘤与单发性颅内转移瘤的价值。方法经手术病理证实的高级别脑胶质瘤23例及单发脑转移瘤15例,术前均行常规MRI及1H-M RS检查。检测肿瘤实质区、瘤周水肿区胆碱(Cho)、肌酸(Cr)、N-乙酰天门冬氨酸(NAA)及脂质(Lip)、乳酸(Lac)的变化,计算Cho/Cr、Cho/NAA及NAA/Cr的比值进行比较。对瘤周Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值进行ROC曲线分析。结果高级别胶质瘤与单发脑转移瘤瘤周水肿区Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值差异有统计学意义(P<0.05)。ROC曲线表明瘤周水肿区Cho/Cr比值为1.33时鉴别高级别脑胶质瘤与脑转移瘤的敏感度、特异度及曲线下面积分别为73.9%、100%、89.3%。而瘤周水肿区Cho/NAA比值为1.25时鉴别高级别脑胶质瘤及脑转移瘤的敏感度、特异性及曲线下面积分别为76.2%、100%、90.7%。结论 M RS波谱分析,特别是对瘤周代谢物比值的测量及ROC曲线分析,能够有效鉴别高级别胶质瘤与脑转移瘤。展开更多
文摘The current standards in radiotherapy of high-grade gliomas(HGG) are based on anatomic imaging techniques, usually computed tomography(CT) scanning and magnetic resonance imaging(MRI). The guidelines vary depending on whether the HGG is a histological grade 3 anaplastic glioma(AG) or a grade 4 glioblastoma multiforme(GBM). For AG, T2-weighted MRI sequences plus the region of contrast enhancement in T1 are considered for the delineation of the gross tumor volume(GTV), and an isotropic expansion of 15 to 20 mm is recommended for the clinical target volume(CTV). For GBM, the Radiation Therapy Oncology Group favors a two-step technique, with an initial phase(CTV1) including any T2 hyperintensity area(edema) plus a 20 mm margin treated with up to 46 Gy in 23 fractions, followed by a reduction in CTV2 to the contrast enhancement region in T1 with an additional 25 mm margin. The European Organisation of Research and Treatment of Cancer recommends a single-phase technique with a unique GTV, which comprises the T1 contrast enhancement region plus a margin of 20 to 30 mm. A total dose of 60 Gy in 30 fractions is usually delivered for GBM, and a dose of 59.4 Gy in 33 fractions is typically given for AG. As more than 85% of HGGs recur in field, dose-escalation studies have shown that 70 to 75 Gy can be delivered in 6 weeks with relevant toxicities developing in < 10% of the patients. However, the only randomized dose-escalation trial, in which the boost dose was guided by conventional MRI, did not show any survival advantage of this treatment over the reference arm. HGGs are amongst the most infiltrative and heterogeneous tumors, and it was hypothesized that the most highly aggressive areas were missed; thus, better visualization of these high-risk regions for radiation boost could decrease the recurrence rate. Innovations in imaging and linear accelerators(LINAC) could help deliver the right doses of radiation to the right subvolumes according to the dose-painting concept. Advanced imaging techniques provide functional info
文摘目的根据肿瘤实质区及瘤周水肿区代谢物的差异,评估磁共振波谱成像对鉴别高级别胶质瘤与单发性颅内转移瘤的价值。方法经手术病理证实的高级别脑胶质瘤23例及单发脑转移瘤15例,术前均行常规MRI及1H-M RS检查。检测肿瘤实质区、瘤周水肿区胆碱(Cho)、肌酸(Cr)、N-乙酰天门冬氨酸(NAA)及脂质(Lip)、乳酸(Lac)的变化,计算Cho/Cr、Cho/NAA及NAA/Cr的比值进行比较。对瘤周Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值进行ROC曲线分析。结果高级别胶质瘤与单发脑转移瘤瘤周水肿区Cho/Cr、Cho/NAA、NAA/Cr及肿瘤实质内Cho/Cr的比值差异有统计学意义(P<0.05)。ROC曲线表明瘤周水肿区Cho/Cr比值为1.33时鉴别高级别脑胶质瘤与脑转移瘤的敏感度、特异度及曲线下面积分别为73.9%、100%、89.3%。而瘤周水肿区Cho/NAA比值为1.25时鉴别高级别脑胶质瘤及脑转移瘤的敏感度、特异性及曲线下面积分别为76.2%、100%、90.7%。结论 M RS波谱分析,特别是对瘤周代谢物比值的测量及ROC曲线分析,能够有效鉴别高级别胶质瘤与脑转移瘤。
