Clinical outcomes using a 3D printed tandem-needle-template and the EMBRACE-II planning aims for image guided adaptive brachytherapy in locally advanced cervical cancer

Biomarker Expression and Clinical Outcomes in International Study of Chemoradiation and Magnetic Resonance Imaging-Based Image-Guided Brachytherapy for Locally Advanced Cervical Cancer: BIOEMBRACE

PURPOSE

BIOEMBRACE was designed to study the impact of biomarkers in addition to clinicopathological factors on disease outcomes in patients treated with chemoradiation and magnetic resonance imaging (MRI)-guided brachytherapy (BT) for locally advanced cervical cancer in the EMBRACE study.

METHODS AND MATERIALS

Between 2018 and 2021, 8 EMBRACE-I sites contributed tumor tissue for the immunohistochemistry of p16, PD-L1, and L1CAM. These biomarkers and clinicopathological factors (International Federation of Gynecology and Obstetrics 2009 stage, nodal status, histology, and necrosis on MRI) were analyzed to predict poor response at BT (high-risk clinical target volume [HR-CTV] ≥ 40 cc) at BT) and 5-year local control, pelvic control, and disease-free survival. Interaction between p16, PD-L1, radiation therapy dose (HR-CTV D90), and disease outcomes was investigated. Univariable and multivariable analyses were performed.

RESULTS

Two hundred sixty-four patients were included. The median HR-CTV D90 was 89 Gy (86-95). P-16 positive status, PD-L1 > 1%, and L1CAM ≥ 10% was noted in 86.6%, 20.1%, and 17.8% of patients, respectively. P16 negative status (odds ratio, 2.0; 95% CI, 1.0-5.7; P = .04) and necrosis on MRI (odds ratio, 2.1; 95% CI, 1.1-4.3; P < .02) independently predicted for HR-CTV ≥ 40 cc, as did the International Federation of Gynecology and Obstetrics stage and tumor width >5 cm. PD-L1 > 1% was associated with reduced local (82% vs 94%; P = .02) and pelvic control (79% vs 89%; P = .02). HR-CTV D90 < 85 Gy was associated with inferior 5-year local control in p16-positive patients, especially if PD-L1 was coexpressed. On multivariable analysis, PD-L1 > 1% was the only independent factor for 5-year local control (hazard ratio, 3.3; P = .04) and L1CAM ≥ 50% for pelvic control (hazard ratio, 5.5; 95% CI, 1.3-23.3; P = .02).

CONCLUSIONS

P16 negative status and tumor necrosis on MRI are independently associated with poor response to chemoradiation, whereas PD-L1 > 1% and L1CAM ≥ 50% have an independent impact on local and pelvic control, suggesting an impact of biomarker expression on outcomes. Further validation is needed.

Automated planning of curved needle channels in 3D printed patient-tailored applicators for cervical cancer brachytherapy

Purpose.Patient-tailored intracavitary/interstitial (IC/IS) brachytherapy (BT) applicators may increase dose conformity in cervical cancer patients. Current configuration planning methods in these custom applicators rely on manual specification or a small set of (straight) needles. This work introduces and validates a two-stage approach for establishing channel configurations in the 3D printed patient-tailored ARCHITECT applicator.Methods.For each patient, the patient-tailored applicator shape was based on the first BT application with a commercial applicator and integrated connectors to a commercial (Geneva) intrauterine tube and two lunar ring channels. First, a large candidate set was generated of channels that steer the needle to desired poses in the target region and are contained in the applicator. The channels' centrelines were represented by Bézier curves. Channels running between straight target segments and entry points were optimised and refined to ensure (dynamic) feasibility. Second, channel configurations were selected using geometric coverage optimisation. This workflow was applied to establish patient-tailored geometries for twenty-two patients previously treated using the Venezia applicator. Treatment plans were automatically generated using the in-house developed algorithm BiCycle. Plans for the clinically used configuration,TPclin, and patient-tailored configuration,TParch, were compared.Results.Channel configurations could be generated in clinically feasible time (median: 2651 s, range 1826-3812 s). AllTParchandTPclinplans were acceptable, but planning aims were more frequently attained with patient-tailored configurations (115/132 versus 100/132 instances). Median CTVIRD98and bladderD2cm3doses significantly improved (p<0.001 andp<0.01 respectively) inTParchplans in comparison withTPclinplans, and in approximately half of the patients dosimetric indices improved.Conclusion.Automated patient-tailored BT channel configuration planning for 3D printed applicators is clinically feasible. A treatment planning study showed that all plans met planning limits for the patient-tailored configurations, and in selected cases improved the plan quality in comparison with commercial applicator configurations.

Brachytherapy for cervical cancer: from intracavitary to interstitial technique

Cervical cancer is a common malignant tumor of female reproductive system. Radiation therapy is one of the main methods of cervical cancer treatment, of which brachytherapy is an essential and important part of radiation therapy for locally advanced cervical cancer. With the rapid development of imaging technologies such as computed tomography (CT) and magnetic resonance imaging (MRI), brachytherapy for cervical cancer has gradually developed from traditional two-dimensional image-guided technology to three-dimensional image-guided technology. And there are more and more treatment methods, including intracavitary brachytherapy, interstitial brachytherapy, and intracavitary combined interstitial implantation brachytherapy. We performed a PubMed search for introduce the application progress of intracavity, implantation, intracavity combined implantation brachytherapy and radioactive seed implantation, and discuss the dosimetric feasibility of internal and external fusion irradiation.

3D-printed brachytherapy in patients with cervical cancer: improving efficacy and safety outcomes

OBJECTIVE

This study aims to evaluate the efficacy and safety of 3D printing technology in brachytherapy for cervical cancer, comparing its outcomes with conventional free hand implantation brachytherapy.

METHODS

A total of 50 cervical cancer patients treated at the First Affiliated Hospital of Gannan Medical College from January 2019 to July 2023 were included in this study. Patients were divided into two groups: 25 patients received intensity-modulated radiotherapy (IMRT) combined with 3D-printed brachytherapy, and 25 patients underwent IMRT combined with free hand brachytherapy implantation. Key indicators analyzed included short-term therapeutic effects, survival outcomes, operation times, the number of CT scans, the number of needles inserted, dosimetric parameters, and complications.

RESULTS

The use of 3D-printed brachytherapy significantly improved the safety of radiation therapy operations, especially for large tumors (≥ 30 mm), by providing more precise dose distribution and reducing the radiation doses received by critical organs such as the bladder and rectum. Compared to the artificial implant group (88% prevalence), the 3D-printed brachytherapy group showed a significantly lower incidence of radiation enteritis (29.2% prevalence, p < 0.001). There were no significant differences in other complications between the two groups. For instance, the incidence of radiation cystitis was relatively high in the 3D-printed brachytherapy group (79.2% prevalence) compared to the artificial implant group (64% prevalence, p = 0.240). The median follow-up period in this study was 22.5 months [IQR 18-29]. Among the 49 patients included, 43 had cervical squamous carcinoma and 6 had cervical adenocarcinoma. Short-term therapeutic response rates were comparable, with no significant difference in overall survival observed between the two groups.

CONCLUSION

3D-printed brachytherapy offers a more effective and safer therapeutic option for patients with cervical cancer, particularly for those with large tumors or complex anatomical structures.

Comparison of 3D-printed multichannel non-co-planar vaginal applicators and single-channel vaginal applicators for brachytherapy with positive or close surgical margins in cervical cancer

OBJECTIVE

This study was conducted to compare the differences between 3D-printed multichannel non-co-planar vaginal applicators and single-channel vaginal applicators in cervical cancer patients with positive or close surgical margins.

METHODS

Between January 2015 and June 2023, 104 cervical cancer patients who underwent radical surgery with positive or close surgical margins were enrolled to receive concurrent intensity-modulated chemoradiotherapy combined with 3D-printed multichannel non-co-planar vaginal applicators (3D-printed group, 41 patients) or single-channel vaginal applicators (single-channel group, 63 patients) guided brachytherapy. The dosimetric parameters, 5-year local control (LC), progression-free survival (PFS), overall survival (OS) of two groups were retrospectively analyzed.

RESULTS

The high-risk clinical target volume (D90, D100) and high-dose volume fraction (V150) in 3D-printed group were significantly higher than those in single-channel group (p < 0.05), and the homogeneity index (HI) and conformal index (COIN) were equally better in 3D-printed group. In 3D-printed group, the D2cc, D1cc, and D0.1cc of the bladder and rectum were significantly lower than those of the single-channel group (p < 0.05). The 3D-printed group had significantly superior 5-year LC (70.0% vs. 51.3%, p = 0.041) and PFS (63.0% vs. 44.2%, p = 0.045), but OS were not significantly different between treatment groups (75.4% vs. 59.7%, p = 0.112). The incidence of radiation enteritis and cystitis was lower in the 3D-printed group than in the single-channel group, but no statistical difference was noted.

CONCLUSIONS

The 3D-printed multichannel non-co-planar vaginal insertion applicators show the advantage of target dose, improve the LC and PFS in patients with positive or close surgical margins after cervical cancer surgery. Thus, the popularization of this method and its application may be of value.

Evaluation and improvement of the safety of 3D-printed template assisted intracavitary/interstitial brachytherapy for cervical cancer using repeat FMEA

BACKGROUND AND PURPOSE

3D-printed templates are used in intracavitary/interstitial brachytherapy (3DP-IC/IS) for locally advanced cervical cancer (LACC). We applied failure mode and effects analysis (FMEA) twice in one year to improve 3DP-IC/IS safety.

MATERIALS AND METHODS

A risk assessment group was established. We created a process map for 3DP-IC/IS procedures, identifying potential failure modes (FMs) and evaluating occurrence (O), detectability (D), severity (S), and risk priority number (RPN = O*D*S). High RPN values identified high-risk FMs, and quality control (QC) methods were determined by root cause analysis. A second FMEA was performed a year later.

RESULTS

The 3DP-IC/IS process included 10 main steps, 48 subprocesses, and 54 FMs. Initial RPN values ranged from 4.50 to 171.00 (median 50.50; average 52.18). Ten high-risk FMs were identified: (1) unreasonable needle track design (171.00/85.50), (2) noncoplanar needle label identification failure (126.00/64.00), (3) template model reconstruction failure (121.50/62.50), (4) improper gauze filling (112.00/60.25), (5) poor needle position (112.00/52.50). QC interventions lowered all high-risk RPN values during the second assessment.

CONCLUSIONS

A feasible 3DP-IC/IS process was proposed. Staff training, automatic needle path planning, insertion guidance diagrams, template checking, system commissioning, and template design improvements effectively enhanced process safety.

High-Dose-Rate Three-Dimensional Image-Guided Adaptive Brachytherapy (3D IGABT) for Locally Advanced Cervical Cancer (LACC): A Narrative Review on Imaging Modality and Clinical Evidence

Background: Brachytherapy (BT) is a critical component of radiotherapy for locally advanced cervical cancer (LACC), and it has rapidly developed in recent decades. Since the advent of three-dimensional image-guided adaptive brachytherapy (3D-IGABT), magnetic resonance imaging (MRI) has emerged as the primary modality for image guidance. Meanwhile, other imaging modalities, such as computed tomography, 18F-fluorodeoxyglucose positron emission tomography, ultrasound, and their combinations have also been widely studied. Materials and methods: We reviewed studies on different imaging modalities utilized for target delineation and planning. Emerging techniques in IGABT like real-time image guidance and 3D printing were also included. We summarized research on their feasibility and concentrated on their clinical outcomes. Results: MRI-guided BT was the gold standard, and CT-guided BT was the most widely applied. Other modalities have shown feasibility and promising efficacy in dosimetry studies and preliminary outcomes. The longer-term clinical outcomes associated with these approaches require further elucidation. Conclusions: As 3D-IGABT was validated by promising clinical outcomes, the future of BT for LACC is expected to progress toward the refinement of more effective image-guided procedures. Moreover, achieving operational consensus and driving technological advancements to mitigate the inherent limitations associated with different imaging modes remain essential.