The efficacy and dosimetry analysis of CT-guided 125I seed implantation assisted with 3D-printing non-co-planar template in locally recurrent rectal cancer

Abstract

Background: Locally recurrent rectal cancer (LRRC) after surgery or external beam radiotherapy (EBRT) is a serious challenge for which no standard treatment is defined. In the present study, we investigated the feasibility of computed tomography (CT)-guided radioactive 125 I seed (RIS) implantation assisted with three-dimensional printing non-coplanar template (3D-PNCT) in LRRC patients who previously received surgery or EBRT. Methods: Sixty-six patients with LRRC treated by CT-guided RIS implantation in our institute from December 2015 to May 2019 were included. The treatment procedure included: preoperative CT localization, planning design, the printing of 3D individualized template, CT-guided RIS implantation assisted with 3D-PNCT, and postoperative dose evaluation. Therapeutic outcomes including local control (LC) and overall survival (OS) were retrospectively evaluated, as well as side effects. Results: All the patients had previously received surgery or EBRT. The median follow-up time was 12.2 (range, 2.5-35.9) months. The median radioactive activity of a single RIS was 0.6 (range, 0.43-0.72) mCi. The median number of RIS was 60, ranging from 10 to 175. The dosimetric parameters included D90 (140.7 ± 33.1) Gy, D100 (90.3 ± 138.6) Gy, and V100 (91.0 ± 13.3) %. Pain relief was achieved in 85.1% (40/47) of patients. Besides, 9.1% (6/66) of patients had severe side effects (≥grade 3), including perianal skin ulcer in 1 case, fistula, radiation proctitis, and intestinal obstruction each in two cases. Median OS time was 14.7 (95% confidence interval (CI): 13.0-16.3) months, and median LC time was 12.2 (95% CI: 9.1-15.2) months. Univariate analysis revealed that when D90 > 130 Gy or D100 > 55 Gy or V100 > 90%, the LC time was remarkably prolonged. However, none of the parameters significantly affected OS. Conclusions: CT-guided RIS implantation assisted with 3D-PNCT is an effective and safe salvage treatment strategy for patients with LRRC after EBRT or surgery. D90, D100, and V100 can be used as prognostic predictors. Trial registration: NCT03890926.

Dosimetric comparison of computed tomography-guided iodine-125 seed implantation assisted with and without three-dimensional printing non-coplanar template in locally recurrent rectal cancer: a propensity score matching study

“…Wang et al . [ 17 ] studied 66 patients with LRRC who were previously treated with EBRT or surgery. Median overall survival (OS) and local control (LC) time were 14.7 and 12.2 months, respectively.…”

“…Previous studies on prostate cancer suggested that the prognosis of patients with D 90 > 140 Gy and V 100 > 90% was significantly better compared to patients with D 90 < 140 Gy or D 100 < 90% [ 19 , 20 , 21 ]. A study on LRRC revealed that patients with D 90 > 130 Gy or V 100 > 90% had a superior prognosis [ 17 ]. One-year local control rates for patients with D 90 > 130 Gy and V 100 > 90% were 72.4% and 69.3%, respectively.…”

The accuracy and dosimetric analysis of 3D-printing non-coplanar template-assisted iodine-125 seed implantation for recurrent chest wall cancer

“…Computed tomography (CT)-guided iodine-125 seed implantation ( 125 I-SI) is proved to be safe and effective when applied in head and neck, thoracic, abdomen, retroperitoneal, and vertebral cancers, especially for locally advanced or recurrent solid cancers after EBRT [6][7][8][9][10][11][12]. 125 I-SI may be applied as a salvage therapy for rCWC alone or as a boost to EBRT, due to rapid dose falling-off and sparing of surrounding organs, while the chest wall is irregular and it may be difficult to perform CT-guided 125 I-SI in patients with rCWC.…”

“…3D-printing non-co-planar template (3D-PNCT) is helpful for high quality performance of CT-guided 125 I-SI [7,8,[12][13][14]. The safety, accuracy, and feasibility of 3D-PNCT application in CT-guided 125 I-SI for cancers raised in complex locations, such as the head and neck, has been explored and reported [7,8,10,[12][13][14][15]. However, the literature on the accuracy and dosimetric analysis of 3D-PNCT-assisted 125 I-SI for rCWC is scarce.…”

PD-1 Inhibitor Maintenance Therapy Combined Iodine-125 Seed Implantation Successfully Salvage Recurrent Cervical Cancer after CCRT: A Case Report

“…A low-dose-rate (LDR) with the computer tomography (CT) guidance and 3-dimensional (3D)-printing non-coplanar template (PNCT) assistance, RISI can achieve an accurate dose delivery and spare the normal tissues. Up to now, 3D PNCT-assisted RISI has presented promising results in the salvage treatment of several kinds of recurrent tumors [ 15 , 16 , 17 , 18 ] and has been referenced in the National Comprehensive Cancer Network guidelines for the management of a locally recurrent rectal cancer [ 19 ]. Meanwhile, existing studies have preliminarily confirmed the efficacy and safety of RISI in the treatment of cervical cancer [ 16 , 20 , 21 ].…”