Mohammadi Homan, Shiue Kevin, Grass G Daniel, Verma Vivek, Engellandt Kay, Daubner Dirk, Schackert Gabriele, Gondim Mercia J, Gondim Dibson, Vortmeyer Alexander O, Kamer Aaron P, Jin William, Robinson Timothy J, Watson Gordon, Yu Hsiang-Hsuan M, Lautenschlaeger Tim
Department of Radiation Oncology, H. Lee Moffitt Cancer Center and Research Institute, Tampa, FL, USA.
Department of Radiation Oncology, Indiana University Simon Cancer Center, Indianapolis, USA.
Neurooncol Pract. 2020 Mar;7(2):185-195. doi: 10.1093/nop/npz050. Epub 2019 Oct 10.
Pseudoprogression (psPD) represents false radiologic evidence of tumor progression and is observed in some glioblastoma (GBM) patients after postoperative chemoradiation (CRT) with temozolomide (TMZ). The ambiguity of the psPD diagnosis confounds identification of true progression and may lead to unnecessary interventions. The association between psPD and isocitrate dehydrogenase 1 () mutational (mut) status is understudied, and its incidence may alter clinical decision making.
We retrospectively evaluated 120 patients with -mut (n = 60) and -wild-type (IDH-WT; [n = 60]) GBMs who received postoperative CRT with TMZ at 4 academic institutions. Response Assessment in Neuro-Oncology criteria were used to identify psPD rates in routine brain MRIs performed up to 90 days after CRT completion.
Within 90 days of completing CRT, 9 GBM patients (1 [1.7%] -mut and 8 [13.3%] -WTs) demonstrated true progression, whereas 17 patients (3 [5%] -muts and 14 [23.3%] -WTs) demonstrated psPD ( = .004). -mut GBMs had a lower probability of psPD (hazard ratio: 0.173, 95% CI, 0.047-0.638, = .008). Among the patients with radiologic signs suggestive of progression (n = 26), psPD was found to be the cause in 3 of 4 (75.0%) of the -mut GBMs and 14 of 22 (63.6%) of the -WT GBMs ( .496). Median overall survival for -mut and -WT GBM patients was 40.3 and 23.0 months, respectively ( < .001).
-mut GBM patients demonstrate lower absolute rates of psPD expression. Irrespective of GBM subtype, psPD expression was more likely than true progression within 90 days of completing CRT. Continuing adjuvant treatment for -mut GBMs is suggested if radiologic progression is suspected during this time interval.
假性进展（psPD）表现为肿瘤进展的假影像学证据，在一些胶质母细胞瘤（GBM）患者术后接受替莫唑胺（TMZ）同步放化疗（CRT）后可观察到。psPD诊断的不明确性混淆了真正进展的识别，并可能导致不必要的干预。psPD与异柠檬酸脱氢酶1（IDH1）突变状态之间的关联研究不足，其发生率可能会改变临床决策。
我们回顾性评估了在4家学术机构接受术后TMZ同步放化疗的120例IDH1突变（n = 60）和IDH1野生型（IDH-WT；n = 60）GBM患者。采用神经肿瘤学反应评估标准，在CRT完成后90天内进行的常规脑部MRI检查中确定psPD发生率。
在完成CRT的90天内，9例GBM患者（1例[1.7%]IDH1突变型和8例[13.3%]IDH1野生型）表现为真正进展，而17例患者（3例[5%]IDH1突变型和14例[23.3%]IDH1野生型）表现为psPD（P = 0.004）。IDH1突变型GBM发生psPD的可能性较低（风险比：0.173，95%CI，0.047 - 0.638，P = 0.008）。在有影像学进展提示的患者（n = 26）中，4例IDH1突变型GBM中有3例（75.0%）和22例IDH1野生型GBM中有14例（63.6%）的原因是psPD（P = 0.496）。IDH1突变型和IDH1野生型GBM患者的中位总生存期分别为40.3个月和23.0个月（P < 0.001）。
IDH1突变型GBM患者表现出较低的psPD表达绝对率。无论GBM亚型如何，在完成CRT的90天内，psPD表达比真正进展更常见。如果在此时间间隔内怀疑有影像学进展，建议对IDH1突变型GBM继续进行辅助治疗。
