Initial and cumulative recurrence patterns of glioblastoma after temozolomide-based chemoradiotherapy and salvage treatment: a retrospective cohort study in a single institution

Table 3 Summary of studies of recurrence patterns of glioblastoma in the temozolomide era

Author	Clinical target delineation and prescribed dose		Analyzed recurrent patients	Proportion of central recurrence
(year)	CTV1 (initial field)	CTV2 (boost field)	Analyzed recurrent patients	Proportion of central recurrence
Brandes et al. [6]	Enhanced tumor area according to preoperative imaging plus 2–3 cm	None (identical with initial field)	79	72.2%^a
Brandes et al. [6]	60 Gy in 30 fractions	None (identical with initial field)	79	72.2%^a
Milano et al. [7]	Edema plus 2 cm	Residual tumor/resection cavity plus 2–2.5 cm	39	80%^b
	46–50 Gy in 23–25 fractions	Residual tumor/resection cavity plus 2–2.5 cm
	46–50 Gy in 23–25 fractions	60 Gy in 30 fractions
Minniti et al. [8]	Residual tumor/resection cavity plus 2 cm	Residual tumor/resection cavity plus 1–2 cm	105	75.2%^c
Minniti et al. [8]	50 Gy in 25 fractions	60 Gy in 30 fractions	105	75.2%^c
McDonald et al. [9]	Edema plus 0.5–1.2 cm	Residual tumor/resection cavity plus 0–1 cm	41	78%^d
	46–54 Gy in 23–30 fractions	Residual tumor/resection cavity plus 0–1 cm
	46–54 Gy in 23–30 fractions	60 Gy in 30 fractions
Dobelbower et al. [10]	Primary tumor and surrounding edema plus 0.5 cm on postoperative imaging	Residual tumor/resection cavity plus 0.5 cm	20	90%^a
		60Gy in 30 fractions
	46 Gy in 23 fractions	60Gy in 30 fractions
Present Study	Residual tumor/resection cavity plus 2 cm and edema	Residual tumor/resection cavity plus 0 cm	21	66.7%
Present Study	50–54 Gy in 25–30 fractions	60 Gy in 30 fractions	21	66.7%

CTV: clinical target volume.
^aThe term “central” was not actually used in the report. Instead, “in-field” recurrence was defined as 80% of the tumor recurrence residing within the prescribed 95% isodose surface.
^bCentral recurrence was defined as growth of the original tumor or arising tumor(s) from the resection cavity.
^cCentral recurrence was defined as more than 95% of the recurrence volume within the 95% isodose line of 60 Gy.
^dCentral recurrence was defined as more than 95% of the recurrence volume inside the 100% isodose line of 60 Gy.

ISSN: 1748-717X