Mendoza Maria G, Azoulay Melissa, Chang Steven D, Gibbs Iris C, Hancock Steven L, Pollom Erqi L, Adler John R, Harraher Ciara, Li Gordon, Gephart Melanie Hayden, Nagpal Seema, Thomas Reena P, Recht Lawrence D, Jacobs Lisa R, Modlin Leslie A, Wynne Jacob, Seiger Kira, Fujimoto Dylann, Usoz Melissa, von Eyben Rie, Choi Clara Y H, Soltys Scott G
Department of Radiation Oncology, Stanford University, Stanford, California.
Department of Radiation Oncology, McGill University Health Centre, Montreal, Quebec, Canada.
Pract Radiat Oncol. 2023 May-Jun;13(3):e239-e245. doi: 10.1016/j.prro.2023.01.008. Epub 2023 Feb 2.
In patients with newly diagnosed glioblastoma (GBM), tumor margins of at least 20 mm are the standard of care. We sought to determine the pattern of tumor progression in patients treated with 5-fraction stereotactic radiosurgery with 5-mm margins.
Thirty adult patients with newly diagnosed GBM were treated with 5-fraction stereotactic radiosurgery in escalated doses from 25 to 40 Gy with a 5-mm total treatment margin. Progression was scored as "in-field" if the recurrent tumor was within or contiguous with the 5-mm margin, "marginal" if between 5 and 20 mm, and "distant" if entirely occurring greater than 20 mm. As geometric patterns of progression do not reflect the biologic dose received, we calculated the minimum equi-effective dose in 2 Gy (EQD2) per day at the site of tumor recurrence. Progression was "dosimetrically in-field" if covered by a minimum EQD2 per day of 48 Gy.
From 2010 to 2016, 27 patients had progressed. Progression was in-field in 17 (63%), marginal in 3 (11%), and distant in 7 (26%) patients. In the 3 patients with marginal progression, the minimum EQD2 to recurrent tumor were 48 Gy, 56 Gy (both considered dosimetrically in-field), and 7 Gy (ie, dosimetrically out-of-field). Median overall survival was 12.1 months for in-field (95% confidence interval [CI], 8.9-17.6), 15.1 months (95% CI, 10.1 to not achieved) for marginal, and 21.4 months (95% CI, 11.2-33.5) for distant progression. Patients with radiation necrosis were less likely to have in-field progression (1 of 7; 14%) compared with those without radiation necrosis (16 of 20; 80%; P = .003); those with necrosis had a median overall survival of 27.2 months (95% CI, 11.2-48.3) compared with 11.7 months (95% CI, 8.9-17.6) for patients with no necrosis (P = .077).
In patients with newly diagnosed GBM treated with a 5-mm clinical target volume margin, 3 patients (11%) had marginal progression within 5 to 20 mm; only 1 patient (4%) may have dosimetrically benefitted from conventional 20-mm margins. Radiation necrosis was associated with in-field tumor control.
在新诊断的胶质母细胞瘤（GBM）患者中，至少20毫米的肿瘤边缘是治疗标准。我们试图确定接受5次分割立体定向放射外科治疗且边缘为5毫米的患者的肿瘤进展模式。
30例新诊断的成年GBM患者接受了5次分割立体定向放射外科治疗，剂量从25 Gy逐步增加到40 Gy，总治疗边缘为5毫米。如果复发肿瘤在5毫米边缘内或与之相邻，则进展被评为“野内”；如果在5至20毫米之间，则为“边缘”；如果完全发生在大于20毫米处，则为“远处”。由于进展的几何模式不能反映所接受的生物剂量，我们计算了肿瘤复发部位每天2 Gy的最小等效剂量（EQD2）。如果每天的最小EQD2覆盖范围为48 Gy，则进展为“剂量学野内”。
2010年至2016年，27例患者出现进展。17例（63%）进展为野内，3例（11%）为边缘，7例（26%）为远处。在3例边缘进展患者中，复发肿瘤的最小EQD2分别为48 Gy、56 Gy（均被视为剂量学野内）和7 Gy（即剂量学野外）。野内进展患者的中位总生存期为12.1个月（95%置信区间[CI]，8.9 - 17.6），边缘进展患者为15.1个月（95% CI，10.1至未达到），远处进展患者为21.4个月（95% CI，11.2 - 33.5）。与无放射性坏死的患者相比，有放射性坏死的患者野内进展的可能性较小（7例中的1例；14%）（20例中的16例；80%；P = 0.003）；有坏死的患者中位总生存期为27.2个月（95% CI，11.2 - 48.3），无坏死的患者为11.7个月（95% CI，8.9 - 17.6）（P = 0.077）。
在接受5毫米临床靶体积边缘治疗的新诊断GBM患者中，3例（11%）在5至20毫米范围内出现边缘进展；只有1例（4%）患者可能从传统的20毫米边缘中获得剂量学益处。放射性坏死与野内肿瘤控制相关。
