CT-guided ¹²⁵I interstitial brachytherapy for pelvic recurrent cervical carcinoma after radiotherapy

Figures & data

Table 1 Patients’ characteristics

Characteristics	Patients (n=33)
Age, years	50.9 (25–76)
<50	19 (57.6)
≥50	14 (42.4)
KPS
<80	15 (45.5)
≥80	18 (54.5)
Histology
SCC	29 (87.9)
Other	4 (12.1)
Initial FIGO stage
I–II	15 (45.5)
III–IV	18 (54.5)
Prior history of radical hysterectomy
Yes	17 (51.5)
No	16 (48.5)
Prior history of chemotherapy
Yes	30 (90.9)
No	3 (9.1)
Previous EBRT dose, Gy	49.6 (16–62)
Prior history of HDR brachytherapy, Gy	24.3 (15–36)
Yes	10 (30.3)
No	23 (67.9)
Location of tumor
Central pelvis	19 (57.6)
Pelvic wall involvement	14 (42.4)
Interval time, months	7.3 (1–18)
<6	10 (30.3)
≥6	23 (69.7)
Maximum tumor diameter, cm	4.9 (2.7–8.4)
<4	9 (27.3)
≥4	24 (72.7)
Extra pelvic metastases
No	12 (36.4)
Yes	21 (63.6)

Notes: Data shown as median (range) or n (%). Initial FIGO stage: clinical staging of patients at initial diagnosis. Maximum tumor diameter is measured from CT before ¹²⁵I brachytherapy. The interval time is defined from the last radiotherapy to seed implantation.

Abbreviations: EBRT, external beam radiotherapy; FIGO, International Federation of Gynecology and Obstetrics; HDR, high-dose rate; KPS, Karnofsky performance status; SCC, squamous cell cancer.

Figure 1 Administration of ¹²⁵I seed brachytherapy.

Notes: (A) The preoperative transverse CT image was obtained to target the area of interest. (B) The radiation oncologist outlined the gross tumor volume (red area) and organs at risk (OARs) for the targeting area including rectum (yellow area) and bladder (green area), therapy planning system determination of the target dose, needle position, and number and distribution of particles. (C) The dose-volume histogram shows the planning target volume (red line) as well as dose distribution in OARs including rectum (yellow line) and bladder (green line). (D) Two months after seed implantation. (E) Six months after seed implantation.

Figure 2 (A) Local tumor progression-free survival after ¹²⁵I brachytherapy. (B) Local tumor progression-free survival in patients with tumors of different sizes. (C) Local tumor progression-free survival with D90≥130 Gy and D90<130 Gy. (D) Overall survival rate after ¹²⁵I brachytherapy. (E) Overall survival rate in patients with different KPS.

Note: D90 is prescribed dose delivered to 90% of the target volume.
Abbreviations: Cum, cumulative; KPS, Karnofsky performance status.

Table 2 Treatment outcomes of ¹²⁵I seed implantation

Follow-up period, months	Local control efficacy (%)
	CR	PR	SD	PD	LC
1	10	18	5	0	28/33 (84.5%)
3	9	14	6	2	23/31 (74.2%)
6	7	8	8	2	15/25 (60.0%)
12	4	1	2	2	5/9 (55.5%)
18	1	0	3	0	1/3 (33.3%)

Note: LC, based on the Response Evaluation Criteria in Solid Tumors, is defined as the proportion of patients with complete response and partial response.

Abbreviations: CR, complete response; LC, local control; PD, progressive disease; PR, partial response; SD, stable disease.

Table 3 Univariate analysis regarding LTPFS and OS

Parameter	Category	P-value (LTPFS)	P-value (OS)
Age, years	<50 vs ≥50	0.565	0.918
KPS	<80 vs ≥80	0.019	<0.001
Histology	SCC vs others	0.239	0.789
Tumor stage	I–IIa vs IIb–IV	0.118	0.909
Prior history of radical hysterectomy	Yes vs no	0.136	0.768
Prior history of chemotherapy	Yes vs no	0.475	0.208
Prior history of HDR brachytherapy	Yes vs no	0.337	0.854
Interval time, months	<6 vs ≥6	0.014	0.803
Location of tumor	Central vs pelvic wall involvement	0.475	0.715
Maximum tumor diameter, cm	<4 vs ≥4	0.006	0.048
Extra pelvic metastases	Yes vs no	0.732	0.016
D90, Gy	<130 vs ≥130	0.022	0.704

Note: D90 is prescribed dose delivered to 90% of the target volume.

Abbreviations: HDR, high-dose rate; LTPFS, local tumor progression-free survival; KPS, Karnofsky performance status; OS, overall survival; SCC, squamous cell cancer.

Table 4 Results of Cox proportional hazards regression analysis for LTPFS and OS

Variable	LTPFS			OS
	P-value	HR	95% CI	P-value	HR	95% CI
KPS
≥80	0.054	0.309	0.154, 1.015	0.001	0.086	0.019, 0.387
<80
Tumor size, cm
<4	0.033	3.357	1.105, 10.212
≥4
D90, Gy
<130	0.035	2.766	1.072, 7.141
≥130

Note: D90 is prescribed dose delivered to 90% of the target volume.

Abbreviations: HR, hazard ratio; KPS, Karnofsky performance status; LTPFS, local tumor progression-free survival; OS, overall survival.

Table 5 Relief of clinical symptoms

Symptoms	SI	PI	IC	AG	RR
Pain	9	6	4	0	15/19 (78.9%)
Fatigue	7	10	6	0	17/23 (73.9%)
Abnormal defecation	2	5	4	1	7/11 (63.3%)
Abdominal distension	3	3	4	0	6/10 (60.0%)
Urinary irritation	4	3	5	1	7/12 (58.3%)
Vaginal discharge	0	3	6	2	3/11 (27.3%)
Vaginal bleeding	3	2	3	1	5/9 (55.6%)
Tenesmus	4	7	5	0	11/16 (62.5%)
Leg edema	0	1	2	0	1/3 (33.3%)

Notes: The relief of clinical symptoms was divided into SI, PI, IC and AG. RR of clinical symptoms was the proportion of SI and PI.

Abbreviations: AG, aggravation; IC, indistinctive change; PI, partial improvement; RR, remission rate; SI, significant improvement.