Tumor-to-Gland Volume Ratio versus Tumor-to-Breast Ratio as Measured on CBBCT: Possible Predictors of Breast-Conserving Surgery

Figures & data

Figure 1 The patient is in the prone position, and the breasts naturally sag through the hole in the center of table. The X-ray tube and detector scan a circle around the breast to obtain a two-dimensional breast projection image. From this a three-dimensional image is reconstructed and uploaded to the image processing system and workstation.

Figure 2 This patient, female, 49 years old, with invasive carcinoma of the right breast, underwent breast-conserving surgery. There are four reconstructed breast images in each figures, which show transverse, sagittal, coronal, and 3D views separately. (A) Red mark represents tumor. Tumor volume is 3.25 cm³. (B) Green mark represents gland, and its volume is 92.17 cm³. Tumor-to-gland volume ratio is 3.53%. (C) Blue mark is right breast and its volume is 445.05 cm³. Tumor-to-breast volume ratio is 0.73%.

Figure 3 This patient, female, 38 years old, with invasive carcinoma of the right breast, underwent mastectomy. There are four reconstructed breast images in each figures, which show transverse, sagittal, coronal, and 3D views separately. (A) Red mark is tumor and its volume is 21.48 cm³. (B) Green mark is gland and its volume is 132.47 cm³. Tumor-to-gland volume ratio is 16.21%. (C) Blue mark is right breast and its volume is 425.80 cm³. Tumor-to-breast volume ratio is 5.04%.

Table 1 Patient Characteristics

	Study Group (Breast-Conserving Surgery)		Control Group (Mastectomy)		X^2	P
	n	%	N	%
Age					6.21	0.18
<40	5	5	9	9
40–49	43	43	28	28
50–59	36	36	39	39
60–69	14	14	22	22
≥70	2	2	2	2
Total	100	100	100	100
Pathological tumor type					1.73	0.63
IDC	55	55	61	61
ILC	35	35	32	32
DCIS	5	5	5	5
Other	5	5	2	2
Total	100	100	100	100

Notes: Carcinoma, micropapillary carcinoma, metaplastic carcinoma, etc.

Abbreviations: IDC, invasive ductal carcinoma; ILC, invasive lobular carcinoma; DCIS, ductal carcinoma in situ.

Table 2 Assessment of the Differences Between Average Volumes and Ratios (Average Tumor, Gland, Breast Volumes and Tumor-to-Gland Volume Ratio, Tumor-to-Breast Volume Ratio) Between the Two Groups

	Study Group	Control Group	Z	P
Average tumor volume (cm^3)	2.48	4.54	–5.32	P<0.001
Average gland volume (cm^3)	73.16	55.54	–3.32	P=0.12
Average breast volume (cm^3)	385.69	377.04	–0.28	P=0.78
Average tumor-to-gland volume ratio	4.32%	10.74%	–6.61	P<0.001
Average tumor-to-breast volume ratio	0.74%	1.36%	–5.46	P<0.001

Figure 4 Comparison of average tumor-to-gland and tumor-to-breast volume ratios in the two groups.