Dosimetry comparison between a 3D printed minimally invasive guidance template and free implantation in the brachytherapy treatment of postoperative recurrent cervical carcinoma

Figures & data

Table 1 Patient characteristics

Variable	Template group	Free group	P-value	Number of cases (%)
Number of cases	11	10		21
Age (years), mean±SD	53.2±7.8	51.8±6.9	0.89
Pathology			1.00
Squamous cell carcinoma	11	9		20 (95.2)
Adenosquamous carcinoma	0	1		1 (4.8)
Recurrence location			0.67
Simple central	6	6		12 (57.1)
Central and pelvic wall	5	4		9 (42.9)
Tumor size (cm), mean±SD	6.3±0.8	6.1±0.6	0.78
Concurrent weekly cisplatin chemotherapy			0.67
Yes	7	7		14 (66.7)
No	4	3		7 (33.3)

Figure 1 Schematic representation of needle track design (A) and 3D-printed minimally invasive-guided template (B).

Figure 2 3D printed minimally invasive guidance template implantation (A) and 3D model after reconstruction of tumor target volume and organs at risk (B). Red refers to the tumor target volume, blue refers to the bladder, yellow refers to the rectum, and pink indicates the sigmoid colon.

Table 2 Therapeutic parameters of the target volume (mean±SD)

Variable	HR-CTV D98(Gy)	HR-CTV D95(Gy)	HR-CTV D90(Gy)
Template group	5.61±0.30	5.96±0.24	6.30±0.21
Free group	5.32±0.39	5.68±0.34	6.07±0.32
P-value	0.007	0.010	0.015

Abbreviation: HR-CTV, high-risk clinical target volume.

Table 3 Therapeutic parameters of the organs at risk (mean±SD)

Variable	Bladder D2cm^3 (Gy)	Rectum D2cm^3 (Gy)	Sigmoid colon D2cm^3 (Gy)	Bowel D2cm^3 (Gy)
Template group	4.78±0.16	4.05±0.21	3.80±0.25	2.91±0.22
Free group	5.07±0.35	4.32±0.31	4.11±0.37	3.23±0.39
P-value	0.002	0.012	0.001	0.001

Abbreviation: D2cm³, illuminated dose of 2 cm³ of organ at risk.

Table 4 Number of CT scans, time for insertion, and number of needles used

Variable	Number of CT scans	Time for insertion (min)	Number of needles
Template group	1.61±0.52	10.21±2.16	5.71±1.82
Free group	3.12±0.82	30.52±6.08	7.78±2.35
P-value	0.039	0.001	0.003

Abbreviation: CT, computed tomography.