Abstract：
OBJECTIVE: Local failure remains the major concern in grade 4 glioma or glioblastoma (GBM). Pilot studies have shown a radiotherapy (RT) dose-response relationship in GBM. Here we present our preliminary data of RT dose escalation using 68Ga-Pentixafor PET scan. High 68Ga-pentixafor uptake in glioma cells helps in sharp demarcation between tumour and normal brain.
METHODS: This phase II prospective study was conducted from 2018 to 2020. Thirty, biopsy-proven cases of grade 4 glioma were included. All patients underwent post-operative MRI of the brain and 68Ga-Pentixafor PET scan. RT was planned in 2-phases. Phase-1 GTV (GTV1) comprised of T2/flair abnormality, PET-avid disease and post-op cavity. A margin of 2cm was given to GTV-1 to create phase-1 CTV (CTV1), which was further expanded to 0.5cm to generate phase-1 PTV (PTV1). A radiation dose of 46Gy/23fr was prescribed to PTV-1. Phase-2 GTV (GTV2) consisted of CT/MRI contrast-enhancing lesion, PET avid disease and post-op cavity. A margin of 0.5 cm was given to GTV2 to create phase-2 CTV (CTV2) which was expanded to 0.5 cm to create phase-2 PTV (PTV2). RT dose of 14 Gy/7 fr was prescribed to PTV2. PET avid disease was delineated as GTV PET and a margin of 3mm was given to generate PTV-PET which received escalated RT dose of 21 Gy/7fr by simultaneous integrated boost (SIB) in phase 2 (Total dose to PTV PET = 67 Gy/30 fr). All patients received concurrent and adjuvant temozolomide. The data was prospectively maintained in Microsoft Excel sheet. SPSS v 23 was used for statistical analysis. The primary endpoints were estimation of the overall survival (OS) and progression-free survival (PFS), and secondary endpoint was to measure the incidence of radiation necrosis. Categorical variables were reported as frequency and percentage and quantitative variables were reported as median and range.
RESULTS: Data from thirty patients were analysed. A median OS of 23 months was observed with estimated 1, 2 and 3 years OS of 90%, 40% and 17.8% respectively. A significant association of OS was seen with the extent of surgery (p = 0.04) and kernofsky performance status (p = 0.007). No patient developed significant radiation necrosis.
CONCLUSIONS: The index study did not show any survival benefit from dose escalation RT. However, all of the patients tolerated the treatment well and none of them developed radiation necrosis. Considering the small sample size as a limitation of the index study, the role of 68Ga-pentixafor PET scan for radiation dose escalation should be further explored.
BACKGROUND: CTRI/2019/05/019146.
METHODS: This phase II prospective study was conducted from 2018 to 2020. Thirty, biopsy-proven cases of grade 4 glioma were included. All patients underwent post-operative MRI of the brain and 68Ga-Pentixafor PET scan. RT was planned in 2-phases. Phase-1 GTV (GTV1) comprised of T2/flair abnormality, PET-avid disease and post-op cavity. A margin of 2cm was given to GTV-1 to create phase-1 CTV (CTV1), which was further expanded to 0.5cm to generate phase-1 PTV (PTV1). A radiation dose of 46Gy/23fr was prescribed to PTV-1. Phase-2 GTV (GTV2) consisted of CT/MRI contrast-enhancing lesion, PET avid disease and post-op cavity. A margin of 0.5 cm was given to GTV2 to create phase-2 CTV (CTV2) which was expanded to 0.5 cm to create phase-2 PTV (PTV2). RT dose of 14 Gy/7 fr was prescribed to PTV2. PET avid disease was delineated as GTV PET and a margin of 3mm was given to generate PTV-PET which received escalated RT dose of 21 Gy/7fr by simultaneous integrated boost (SIB) in phase 2 (Total dose to PTV PET = 67 Gy/30 fr). All patients received concurrent and adjuvant temozolomide. The data was prospectively maintained in Microsoft Excel sheet. SPSS v 23 was used for statistical analysis. The primary endpoints were estimation of the overall survival (OS) and progression-free survival (PFS), and secondary endpoint was to measure the incidence of radiation necrosis. Categorical variables were reported as frequency and percentage and quantitative variables were reported as median and range.
RESULTS: Data from thirty patients were analysed. A median OS of 23 months was observed with estimated 1, 2 and 3 years OS of 90%, 40% and 17.8% respectively. A significant association of OS was seen with the extent of surgery (p = 0.04) and kernofsky performance status (p = 0.007). No patient developed significant radiation necrosis.
CONCLUSIONS: The index study did not show any survival benefit from dose escalation RT. However, all of the patients tolerated the treatment well and none of them developed radiation necrosis. Considering the small sample size as a limitation of the index study, the role of 68Ga-pentixafor PET scan for radiation dose escalation should be further explored.
BACKGROUND: CTRI/2019/05/019146.
摘要：
目的：局部衰竭仍然是4级胶质瘤或胶质母细胞瘤（GBM）的主要问题。初步研究表明，GBM中存在放疗（RT）剂量反应关系。在这里，我们提供了使用68Ga-Pentixa进行PET扫描的RT剂量递增的初步数据。神经胶质瘤细胞中68Ga-pentixa的高摄取有助于肿瘤和正常大脑之间的清晰划分。
方法：这项II期前瞻性研究于2018年至2020年进行。三十,活检证实的4级胶质瘤病例包括在内.所有患者均接受脑部术后MRI和68Ga-PentixaPET扫描。RT计划分两个阶段进行。第1阶段GTV(GTV1)包括T2/Flair异常,PET-狂热的疾病和术后腔。给予GTV-12cm的余量以创建阶段1CTV（CTV1），进一步扩展到0.5cm以产生1相PTV（PTV1）。对PTV-1规定了46Gy/23fr的辐射剂量。2期GTV（GTV2）包括CT/MRI对比增强病变，PET狂热疾病和术后腔。给予GTV20.5cm的余量以产生阶段2的CTV（CTV2），将其扩展至0.5cm以产生阶段2的PTV（PTV2）。PTV2的RT剂量为14Gy/7fr。PET狂热疾病被描述为GTVPET，并给予3mm的边缘以产生PTV-PET，该PTV-PET在第2阶段通过同时整合增强（SIB）接受了21Gy/7fr的递增RT剂量（PTVPET的总剂量=67Gy/30fr）。所有患者同时接受替莫唑胺辅助治疗。数据前瞻性地保存在MicrosoftExcel表中。采用SPSSv23进行统计分析。主要终点是估计总生存期（OS）和无进展生存期（PFS），次要终点是测量放射性坏死的发生率。分类变量报告为频率和百分比，定量变量报告为中位数和范围。
结果：分析了30例患者的数据。中位OS为23个月，估计1年、2年和3年OS为90%，分别为40%和17.8%。OS与手术程度（p=0.04）和kernofsky表现状态（p=0.007）显着相关。没有患者出现明显的放射性坏死。
结论：指标研究未显示剂量递增RT的任何生存益处。然而,所有患者对治疗的耐受性良好，均未发生放射性坏死。考虑到小样本量是指标研究的局限性，应进一步探讨68Ga-pentixa对PET扫描辐射剂量递增的作用.
背景：CTRI/2019/05/019146。
方法：这项II期前瞻性研究于2018年至2020年进行。三十,活检证实的4级胶质瘤病例包括在内.所有患者均接受脑部术后MRI和68Ga-PentixaPET扫描。RT计划分两个阶段进行。第1阶段GTV(GTV1)包括T2/Flair异常,PET-狂热的疾病和术后腔。给予GTV-12cm的余量以创建阶段1CTV（CTV1），进一步扩展到0.5cm以产生1相PTV（PTV1）。对PTV-1规定了46Gy/23fr的辐射剂量。2期GTV（GTV2）包括CT/MRI对比增强病变，PET狂热疾病和术后腔。给予GTV20.5cm的余量以产生阶段2的CTV（CTV2），将其扩展至0.5cm以产生阶段2的PTV（PTV2）。PTV2的RT剂量为14Gy/7fr。PET狂热疾病被描述为GTVPET，并给予3mm的边缘以产生PTV-PET，该PTV-PET在第2阶段通过同时整合增强（SIB）接受了21Gy/7fr的递增RT剂量（PTVPET的总剂量=67Gy/30fr）。所有患者同时接受替莫唑胺辅助治疗。数据前瞻性地保存在MicrosoftExcel表中。采用SPSSv23进行统计分析。主要终点是估计总生存期（OS）和无进展生存期（PFS），次要终点是测量放射性坏死的发生率。分类变量报告为频率和百分比，定量变量报告为中位数和范围。
结果：分析了30例患者的数据。中位OS为23个月，估计1年、2年和3年OS为90%，分别为40%和17.8%。OS与手术程度（p=0.04）和kernofsky表现状态（p=0.007）显着相关。没有患者出现明显的放射性坏死。
结论：指标研究未显示剂量递增RT的任何生存益处。然而,所有患者对治疗的耐受性良好，均未发生放射性坏死。考虑到小样本量是指标研究的局限性，应进一步探讨68Ga-pentixa对PET扫描辐射剂量递增的作用.
背景：CTRI/2019/05/019146。
