Impact of 18F-FDG PET/CT on target volume delineation in recurrent or residual gynaecologic carcinoma

Radiation Oncology

Table 2 Summary of the composite and common volumes of GTV _CT1 and GTV _PET/CT1 as well as overlap fractions (OFs) between the GTV _CT1 , GTV _PET/CT1 and GTV _SBR

Pat. No.	Composite volume PET/CT	Common volume PET/CT	OF_CT1	OF_PET/CT1	OF_SBR
	Mean (cm³) (SD)	Mean (cm³) (SD)	Mean (cm³) (SD)	Mean (cm³) (SD)	Mean (cm³) (SD)
1	6.95	5.02	0.72	0.91	0.96
	(SD 1.32)	(SD 0.95)	(SD 0.03)	(SD 0.04)	(SD 0.04)
2	47.24	46.73	0.55	0.81	1.00
	(SD 11.80)	(SD 5.43)	(SD 0.04)	(SD 0.04)	(SD 0.00)
3	64.82	44.56	0.59	0.93	1.00
	(SD 6.02)	(SD 13.68)	(SD 0.04)	(SD 0.02)	(SD 0.00)
4	95.99	99.61	0.57	1.00	1.00
	(SD 8.01)	(SD 1.63)	(SD 0.05)	(SD 0.00)	(SD 0.00)
5	20.35	20.82	0.45	0.81	0.91
	(SD 6.53)	(SD 4.45)	(SD 0.03)	(SD 0.03)	(SD 0.08)
6	2.81	2.43	0.77	0.98	1.00
	(SD 0.75)	(SD 0.62)	(SD 0.03)	(SD 0.03)	(SD 0.00)
7	26.16	12.89	0.61	0.85	0.90
	(SD 1.99)	(SD 0.94)	(SD 0.06)	(SD 0.06)	(SD 0.05)
8	66.43	50.11	0.46	1.00	1.00
	(SD 14.08)	(SD 2.31)	(SD 0.03)	(SD 0.00)	(SD 0.00)
9	27.64	19.48	0.67	0.96	1.00
	(SD 0.94)	(SD 2.78)	(SD 0.03)	(SD 0.04)	(SD 0.00)
10	105.06	97.49	0.87	0.79	0.97
	(SD 2.74)	(SD 9.30)	(SD 0.10)	(SD 0.02)	(SD 0.03)

The composite volume PET/CT is the sum of GTV_CT1 and GTV_PET/CT1 while the common volume PET/CT is the joint volume of GTV_CT1 and GTV_PET/CT1 of each observer. [OF_CT1] is the overlap fraction (OF) of GTV_PET/CT1 relative to GTV_CT1 while [OF_PET/CT1] is the OF of GTV_CT1 relative to GTV_PET/CT1 and [OF_SBR] is the OF of GTV_PET/CT1 relative to GTV_SBR. SBR = Signal-to-background ratio.

ISSN: 1748-717X