3D printing in brachytherapy: A systematic review of gynecological applications

Bioprinting functional constructs for women's reproductive health: Utilizing tailored biomaterials and biopolymer macromolecules for drug delivery and tissue regeneration

The application of 3D bioprinting, combined with the versatility of biomaterials and biopolymers macromolecules is revolutionizing the landscape of women's reproductive health. Biomaterials, including both natural and synthetic variants, offer unmatched biocompatibility, degradability, and functional adaptability, enabling the development of innovative solutions for complex reproductive disorders. This review examines the pivotal role of biomaterials and biopolymers macromolecules in creating scaffolds, bioinks, and drug delivery systems tailored to address disorders such as endometriosis, polycystic ovary syndrome, gynecological cancers, and so on. By integrating biomaterials, 3D bioprinting overcomes anatomical and physiological challenges unique to the female reproductive tract, such as cyclic hormonal variations and diverse microbiomes, ensuring precise and personalized healthcare interventions. The potential of various polymer-based hydrogels (biomaterials and biopolymers) in sustained drug delivery and regenerative tissue applications is highlighted, along with advancements in tissue-engineered constructs for reproductive health restoration. This amalgamation of polymer science and 3D bioprinting not only enhances therapeutic outcomes but also paves the way for innovative advancements in women's healthcare, addressing long-standing challenges with unparalleled precision and efficacy.

Development and implementation of a 3d-HDR brachytherapy program for cervical cancer in a sub-Saharan African centre

BACKGROUND

Cervical cancer is the second most common cancer among women in Nigeria where, the gap between need for, and access to, radiation therapy including brachytherapy is significant. This report documents the implementation of the first three-dimensional high-dose-rate (3D-HDR) brachytherapy service for cervical cancer in Nigeria.

PURPOSE

This report details the steps taken to implement the 3D-HDR brachytherapy program, the challenges faced, and the adaptive strategies employed to overcome them. Our objective is to provide a guide for teams and centers in similar resource-restricted settings to implement 3D-HDR brachytherapy services, by leveraging our shared experience and lessons learned.

METHOD AND METERIALS

The implementation process required investment in infrastructure: creating a dedicated brachytherapy suite equipped with modern technology; and human capital: conducting both virtual and hands-on training for staff; and involving international experts during the initial treatment phases. Quality assurance protocols were established to ensure the accuracy and safety of treatments. Key adaptations included extensive remote training, international experts flying in for the initiation phase, and preemptively re-ordering the radioisotope to prevent delays.

RESULTS

The 3D-HDR brachytherapy program was successfully implemented, with five cases treated in the first 2 months despite challenges such as high equipment costs, expertise and proficiency needs, and source replacement delays. Continuous training and quality assurance measures ensured the program's sustainability and effectiveness.

CONCLUSIONS

Implementing a 3D-HDR brachytherapy program in a system with restricted resources is possible with thorough planning, flexible strategies, and adaptive measures. We document our experience to provide insights for other institutions aiming to establish similar programs. Collaboration and innovative financial strategies are essential for ensuring sustainable access to cancer treatment in the region. Strategies such as remote training and proactive resource management, are critical for overcoming implementation barriers.

Application of 3D printing technology in the surgical management of advanced ovarian serous carcinoma: a case report

Advanced ovarian serous carcinoma presents significant surgical challenges due to tumor size, deep location, and complex anatomical relationships with surrounding structures. This case report highlights the use of 3D printing technology to improve surgical planning and outcomes in such complex scenarios. A 48-year-old female presented with bilateral ovarian tumors, confirmed as serous cystadenocarcinoma. Preoperative 3D modeling was employed to create a detailed anatomical model based on imaging data. This model provided precise visualization of tumor size, vascular supply, and relationships with adjacent organs, facilitating the development of an optimal surgical plan. During surgery, bilateral ovarian tumors were resected along with the uterus, omen tum, and lymph nodes, achieving complete R0 resection. Postoperatively, the patient recovered well, with no complications or recurrence observed during follow-up. This case underscores the value of 3D printing in enhancing surgical precision and safety in complex gynecological oncology cases. By providing individualized anatomical insights, 3D printing supports preoperative planning, improves patient outcomes, and contributes to advancing precision medicine in surgical practice.

IPEM topical report: guidance on 3D printing in radiotherapy

There has been an increase in the availability and utilization of commercially available 3D printers in radiotherapy, with applications in phantoms, brachytherapy applicators, bolus, compensators, and immobilization devices. Additive manufacturing in the form of 3D printing has the advantage of rapid production of personalized patient specific prints or customized phantoms within a short timeframe. One of the barriers to uptake has been the lack of guidance. The aim of this topical review is to present the radiotherapy applications and provide guidance on important areas for establishing a 3D printing service in a radiotherapy department including procurement, commissioning, material selection, establishment of relevant quality assurance, multidisciplinary team creation and training.

Individual curved-needle interstitial template created using three-dimensional printing for brachytherapy for distal parauterine tumor recurrence

BACKGROUND

Achieving a clinically acceptable dose distribution with commercial vaginal applicators for brachytherapy of recurrent parauterine tumors is challenging. However, the application of three-dimensional (3D) printing technology in brachytherapy has been widely acknowledged and can improve clinical treatment outcomes.

PURPOSE

This study aimed to introduce an individual curved-needle interstitial template (ICIT) created using 3D printing technology for high-dose-rate (HDR) brachytherapy with interstitial treatment to provide a clinically feasible approach to distal parauterine and vaginal cuff tumors. The entire workflow, including the design, optimization, and application, is presented.

METHODS

Ten patients with pelvic cancer recurrence were examined at our center. The vaginal topography was filled with gauze strips soaked in developer solution, and images were obtained using computed tomography (CT) and magnetic resonance imaging (MRI). Curved needle paths were designed, and ICITs were 3D-printed according to the high-risk clinical target volume (HRCTV) and vaginal filling model. The dose and volume histogram parameters of the HRCTV (V100, V200, D90, and D98) and organs at risk (OARs) (D2cc) were recorded.

RESULTS

All patients completed interstitial brachytherapy treatment with the 3D-printed ICIT. One patient experienced vaginal cuff tumor recurrence, and nine patients experienced parametrial tumor recurrence (four on the left and five on the right). We used two to five interstitial needles, and the maximum angle of the curved needle was 40°. No source obstruction events occurred during treatment of these 10 patients. The doses delivered to the targets and OARs of all patients were within the dose limits and based on clinical experience at our center.

CONCLUSION

The ICIT is a treatment option for patients with distal parauterine tumor recurrence. This method addresses the limitations of vaginal intracavitary and standard interstitial applicators. The ICIT has the advantages of biocompatibility, personalization, and magnetic resonance imaging compatibility.

A novel 3D printing method for a notched eye plaque "dummy" for uveal melanoma brachytherapy

PURPOSE

Suture preplacement by the ocular oncology surgeon is a critical step before inserting a radioactive plaque for ocular melanoma brachytherapy. We report on a novel 3D-printing method to create a custom "dummy" plaque applicator for the 22 mm notched gold plaque using in-house 3D-printing.

METHODS

A computer-aided design (CAD) file was created replicating a heavily used gold plaque that no longer has a satisfactory "dummy" plaque. The file was exported as a 3D file (surface tessellation language, STL) and prepared using Formlabs' PreForm print software. The 3D-printed dummies were oriented on the printer to have no cups or supports on the surfaces that would come in contact with the patient's external sclera. The dummies were printed in FormLabs BioMed Clear V1 on a Formlabs Form-3 3D printer. Postprinting, the dummies were processed in isopropyl alcohol and cured according to manufacturer instructions. They were polished utilizing a rotary tool to improve transparency. Chemical and sterilization cycle tests were performed to ensure dummy integrity.

RESULTS

Four "dummy" plaques were printed. The 3D-printed "dummy" dimensions were verified to be within 0.5-mm of the notched plaque using digital calipers. The polishing process created acceptable light opacity for the eye plaque procedure in the operating room. No impactful discoloration or material change was observed during the chemical and sterilization cycle tests performed.

CONCLUSIONS

3D printing can produce custom eye plaque dummies using transparent, biocompatible, chemically inert materials suitable for human use. This capability introduces an additional layer of patient-specific hygienics.

A novel multi-channel applicator with a U-shaped channel for vaginal intracavity brachytherapy

BACKGROUND

Endometrial cancer is one of the most common gynecological malignancies in the world. Vaginal brachytherapy is an important postoperative adjuvant treatment for endometrial cancer. However, a common problem with existing applicators is insufficient dose at the vaginal apex.

PURPOSE

This study describes the Hangzhou (HZ) cylinder, a novel 3D printed vaginal intracavity brachytherapy applicator, detailing its characteristics, dose distribution, and clinical applications.

METHODS AND MATERIALS

The HZ cylinder is distinguished by its unique structure: a U-shaped channel with a 2 mm diameter, a straight central axis channel of the same diameter, and 10 parallel straight channels. For comparison, standard plans were employed, designed to ensure that a minimum of 95% of the prescribed dose reached 5 mm beneath the mucosal surface. We conducted comparative analyses of mucosal surface doses and doses at a 5 mm depth below the mucosa between the HZ cylinder and a conventional single-channel cylinder across various treatment schemes. Additionally, the study examined dose differences in target volume and organs at risk (OARs) between actual HZ cylinder plans and hypothetical single-channel plans.

RESULTS

In the standard plans, mucosal surface doses at the apex of the vagina were 209.32% and 200.61% of the prescribed dose with the HZ and single-channel cylinders, respectively. The doses on the left and right wall mucosal surfaces varied from 149.26% to 178.13% and 142.98% to 180.75% of the prescribed dose, and on the anterior and posterior wall mucosal surfaces varied from 128.87% to 138.50% and 142.98% to 180.75% of the prescribed dose. Analysis of 24 actual treatment plans revealed that when the vaginal tissue volume dose covering 98% (vaginal D98%) was comparable between the HZ cylinder and virtual single-channel plans (6.74 ± 0.07 Gy vs. 6.69 ± 0.10 Gy, p = 0.24), rectum doses of HZ cylinder plans were significantly lower than those of single-channel plans (D1cc, 5.96 ± 0.56 Gy vs. 6.26 ± 0.71 Gy, p = 0.02 and D2cc, 5.26 ± 0.52 Gy vs. 5.56 ± 0.62 Gy, p = 0.02).

CONCLUSIONS

The HZ cylinder demonstrates a reduction in dose to the rectum and bladder while maintaining adequate target volume coverage. Its mucosal surface dose is comparable to that of the traditional single-channel cylinder. These findings suggest that the HZ cylinder is a viable and potentially safer alternative for vaginal brachytherapy, warranting further investigation with larger sample sizes.

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.

Gynecological brachytherapy hybrid training: The Tata Memorial Centre and BrachyAcademy experience

PURPOSE

The lack of training is a significant barrier to practicing brachytherapy (BT). Tata Memorial Centre, alongside international BT experts and BrachyAcademy, developed a hybrid gynecological BT training module. This study outlines the preparation, organization, and execution of the 2022-2023 Mumbai training, evaluates its effectiveness, and highlights areas for improvement.

MATERIALS AND METHODS

Participants were radiation oncologists (RO) and medical physicists (MP) with experience in gynecological BT aiming to transition to image-guided brachytherapy (IGBT). The training covered cervical, endometrial, vaginal, vulvar, periurethral cancers, and pelvic reirradiation. The hybrid course included online pre and postcourse homework assignments, a live workshop with hands-on training, a 6-month online follow-up, and a 12-month opportunity to share the transition experience.

RESULTS

The December 2022 Mumbai live workshop spanned 2.5 days, attracting 39 participants from 8 countries (Asia, Africa, Australia/Oceania). Feedback rated the course 9/10, with 78% fully meeting expectations. Forty-four percent suggested extending hands-on training. At the 6-month follow-up, response rates were low (33% RO, 11% MP). Among responding RO, 70% reported practice changes after attending the course, 40% implemented IGBT concepts in clinical practice, and 50% increased confidence in image-guided procedures. Overall, 45% of respondent sites could strengthen their intracavitary/interstitial program, while others faced limitations due to lack of access to advanced BT applicators.

CONCLUSION

The hybrid gynecological BT training concept was successfully executed. Areas for improvement include extending hands-on training and enhancing participant engagement postcourse. Structured steps beyond training may be needed to improve the utilization of advanced brachytherapy for gynecological cancers.

Phantom study of a fully automatic radioactive seed placement robot for the treatment of skull base tumours

BACKGROUND

Interstitial brachytherapy is a form of intensive local irradiation that facilitates the effective protection of surrounding structures and the preservation of organ functions, resulting in a favourable therapeutic response. As surgical robots can perform needle placement with a high level of accuracy, our team developed a fully automatic radioactive seed placement robot, and this study aimed to evaluate the accuracy and feasibility of fully automatic radioactive seed placement for the treatment of tumours in the skull base.

METHODS

A fully automatic radioactive seed placement robot was established, and 4 phantoms of skull base tumours were built for experimental validation. All the phantoms were subjected to computed tomography (CT) scans. Then, the CT data were imported into the Remebot software to design the preoperative seed placement plan. After the phantoms were fixed in place, navigation registration of the Remebot was carried out, and the automatic seed placement device was controlled to complete the needle insertion and particle placement operations. After all of the seeds were implanted in the 4 phantoms, postoperative image scanning was performed, and the results were verified via image fusion.

RESULTS

A total of 120 seeds were implanted in 4 phantoms. The average error of seed placement was (2.51 ± 1.44) mm.

CONCLUSION

This study presents an innovative, fully automated radioactive particle implantation system utilizing the Remebot device, which can successfully complete automated localization, needle insertion, and radioactive particle implantation procedures for skull base tumours. The phantom experiments showed the robotic system to be reliable, stable, efficient and safe. However, further research on the needle-soft tissue interaction and deformation mechanism of needle puncture is still needed.