QUESTIONS

The UFO is composed of Nylon 12, and it was manufactured using nylon powder in multi-jet fusion 3D-printing. Nylon 12 is a thermoplastic polymer that is lightweight, durable, visible on CT imaging, and has previously been used to develop medical devices. Moreover, it is able to be printed with a smooth surface, without the rough layers that are otherwise typically seen in filament 3D-printing. The material is also biocompatible and autoclavable, allowing the UFO to fit into the current workflow of brachytherapy by being sterilizable and compatible with tissue/bodily fluids.

Our device was developed within the Global Health department and designed to be implemented in low-resource settings. Because the UFO has precise detailing, like its channels, high-resolution 3D-printers must be used, but this process is not necessarily cheap - currently, at small-scale, each device costs approximately $180, a significant cost for low-resource settings. Due to its high-quality design, it is simply not economical for the UFO to be single-use, especially since the standard for current brachytherapy equipment is to be reusable and Nylon-12 is already autoclavable. We anticipate the UFO channels will be cleaned and sterilized using high-pressure water systems and chemical solutions with cleaning brushes before being autoclaved.

Our project collaborators, radiation oncologists Dr. Ludwig and Dr. Hanania, have had significant input on the shape of our device. Both have repeatedly confirmed that the UFO device, with its dimensions, can easily be inserted into the patient. Together, we determined that the optimal shape for the UFO was a wider 6cm head to stabilize the device within the vaginal canal space at the cervix and the cervical fornices.

The remaining cylindrical shape is modeled after the standard equipment. All edges of the device are rounded and smooth, and the flattened head (instead of a spherical one) allows the UFO to rest firmly against the cervix. The wider head is also required for the needles to gradually bend within the UFO's internal template before entering the tumor. Initially, we considered a flexible head for the UFO, but the doctors determined that this was unnecessary given the small size of our design.

Brachytherapy is extremely traumatic to the reproductive tissues, and the current equipment greatly contributes to patient morbidity and pain. So, despite its wider head, the UFO and our proposed method of treatment is significantly more comfortable than current methods.

All current devices on the market continue to rely on the use of transcutaneous needles that cause significant harm to healthy tissue. They are highly expensive, unavailable globally, only usable with company-specific equipment, and are highly complex, like Varian's Elekta device. The UFO’s simple, efficient design separates itself from devices on the market by being low-cost, compatible with equipment of most brachytherapy companies, and accessible globally. Currently, a tandem, a metal rod inserted into the uterus, is used to provide concentrated high-dose radiation to the cervix. However, many women battling cervical cancer have had a complete hysterectomy and do not have a uterus. In these cases, a tandem cannot be used, as it cannot be inserted, so their tumors cannot be optimally treated. The UFO is the only device on the market with an option that accommodates a needle instead of a tandem, enabling the cervix to be irradiated for women without a uterus. The features of the UFO clearly improve upon the currently available equipment.

A physician is necessary to complete this procedure. The UFO reduces the skill level required to carry out cervical cancer brachytherapy, because even inexperienced professionals are able to accurately slide needles into the UFO’s channels. There is less technical knowledge needed, since now the person carrying out the procedure does not have to be as meticulous with needle placement. However, a physician's expertise is still needed to properly locate a tumor site, determine how many needles are needed to irradiate it, and which channels should be used to accomplish this.

Uterus length can vary slightly from patient to patient, and the UFO has 13cm and 15cm options (as is the standard for current brachytherapy equipment) to accommodate for this variation. Moreover, the UFO is unique compared to current equipment, as it can be used to comprehensively treat patients with complete hysterectomies (without a uterus). Currently, a tandem, a metal rod inserted into the uterus during brachytherapy to irradiate the cervix itself, cannot be used on women with complete hysterectomies, as it cannot be inserted without a uterus. If a needle was fed centrally into the cervix, the tumors could still be comprehensively treated, but current equipment does not accommodate this. The UFO comes with options to address this issue. One version of the UFO has a tandem-sized central channel to treat patients with a uterus, and another version of the UFO has a needle-sized central channel to be able to irradiate the cervix for patients without a uterus.

Generally speaking, the device could be customized to a particular patient. However, the UFO already has 4 available options for adaptability: 2 options for varying vaginal canal lengths and 2 options for treating patients with and without a uterus. These 4 options will be sufficient enough to treat 90% of cervical cancer cases, making the UFO a much cheaper alternative for customization, since customizing brachytherapy applicators involves having to individually scan each patient, design the device to their anatomy, and successfully print the personalized device.

In fact, there are existing initiatives to manufacture customizable brachytherapy applicators, for multiple different types of brachytherapy - not just cervical cancer. However, these customizable applicators are time-intensive and extremely costly to create due to the process behind them, making them unsustainable and inaccessible in low-resource settings.

Our team has considered molding as an alternative manufacturing method for the device, and we have been in contact with companies that offer this service. However, because of the current stage and scale of the device, molding does not appear to be a cost-effective or feasible manufacturing method. Moreover, with 3D printing, the UFO is manufactured in Nylon 12 using nylon powder in multi-jet fusion 3D-printing, and this process ensures that the device has completely smooth surfaces, mitigating any risks of splintering or defects from layering that could prevent the UFO from being biocompatible.

In the current brachytherapy procedure, before needle insertion, doctors scan the patient using CT to create a dosimetry plan in which they determine the number of needles and the arrangement of needles necessary to reach the full extent of the patient's tumor. Currently, an external template is typically used to guide needles, and it arranges needles on 1cm concentric arcs. This arrangement provides uniform radiation distribution, because the 1cm separation between needles provides even radiation across the tumor, preventing gaps and hot spots. The UFO mirrors this standard of arrangement on its internal template, but also adds an additional 4 channels that are able to reach usually untreatable areas too close to surrounding vital structures. The UFO fits seamlessly into the brachytherapy procedure, and the same steps for the procedure are taken, including CT scanning the patient and creating a dosimetry plan before needle insertion. The only thing that has changed is the applicator used to insert the needles.

Due to its internal template, composed of angled channels, the UFO is able to gently bend the needles to flare out and reach a wider diameter. The outermost channels of the device guide needles to spread out to 8cm in diameter. Radiation seeds within the needles irradiate approximately 1cm diameter around, allowing needles within the UFO to effectively treat up to a 9cm tumor.

The UFO can greatly lower the risk of various brachytherapy-related complications, including fistulas. Using the UFO, all needles are guided within the vaginal canal and only exposed to tissue towards the cervix at the site of the tumor, 'bypassing' surrounding vital structures and significantly reducing any potential contact that could cause fistulas between the cervix and bladder or the cervix and rectum.