Intra-Arterial Paraplatin Shows No Hearing Loss in Retinoblastoma

DPOAE testing showed no hearing loss in children with retinoblastoma treated with intra-arterial paraplatin: © stock.adobe.com.

Hearing loss was not linked to intra-arterial Paraplatin (carboplatin) when measured using distortion product otoacoustic emission measurement (DPOAE) testing in children with retinoblastoma, according to study findings presented at the 50^th Annual Oncology Nursing Society Congress.

“As novel cancer modalities become standard practice, care must be taken to investigate and pre-mitigate potential toxicities,” Mary Elizabeth Davis wrote in her presentation. “Retinoblastoma is a curable cancer. For children acquiring language, even small losses of hearing can lead to communication difficulties.”

Enrollment and study completion were significantly affected by the COVID-19 pandemic. Of the 40 enrolled patients, 22 completed both pre- and post-testing and were evaluable. Participants ranged in age from 2 months to 4.5 years, with a mean age of 16 months. Sixteen were female. No measurable hearing loss was observed in any child. These findings suggest that intra-arterial Paraplatin does not affect outer hair cell function. Additionally, DPOAE can provide useful information when monitoring children at risk of developing Paraplatin ototoxicity.

What is Retinoblastoma and How is it Cured?

Retinoblastoma is the most common primary eye cancer in children, with about 8,000 cases diagnosed globally each year, according to the abstract of the presentation. It can be cured using multimodal treatments, including intravenous chemotherapy with Paraplatin, etoposide and vincristine. However, this approach often causes serious side effects such as bone marrow suppression, nausea and vomiting, and irreversible hearing loss from Paraplatin. To reduce toxicity, many institutions now deliver chemotherapy for retinoblastoma solely through intra-arterial administration.

“Hearing loss from intravenous Paraplatin is usually irreversible,” wrote Elizabeth in the presentation. “In recent years, at many institutions, chemotherapy for retinoblastoma is now given by intra-arterial administration.”

What is Distortion Product Otoacoustic Emission Measurement Testing?

According to the National Library of Medicine, distortion product otoacoustic emissions, or DPOAEs, are sounds created by the inner ear that help reflect how well the outer hair cells and cochlea work. In clinical settings, they’re a quick, noninvasive way to screen for hearing loss — especially helpful for testing newborns and young children. Because they’re easy to perform and give reliable results, DPOAEs are used for both routine hearing checks and more detailed evaluations when hearing issues are suspected.

Over the past decade, experts have improved how DPOAEs are recorded, making the results even more accurate. In research, DPOAEs are also valuable for studying how the cochlea functions at different sound frequencies. Techniques like ipsilateral suppression, where researchers observe how DPOAEs change in response to sound in the same ear, have been used to learn more about how hearing develops in infants.

With their strong clinical and research applications, DPOAEs continue to be a vital part of hearing care and auditory science, as per the presentation.

Study Design and Methods

The prospective pre-posttest study evaluated hearing in children receiving intra-arterial Paraplatin, according to the abstract of the presentation. Children were excluded if they had prior intra-arterial Paraplatin or hearing loss, but those who had received intravenous Paraplatin with available dosing data were included. Hearing was assessed before intra-arterial chemotherapy and again three to nine months after treatment.

Given the young age at diagnosis, DPOAE served as the primary evaluation tool. Although not a direct measure of hearing, DPOAE correlates with cochlear function: present responses suggest normal cochlear amplification, while absent responses indicate dysfunction. Tympanometry ensured the absence of middle ear fluid. A certified audiologist performed all evaluations using consistently calibrated equipment.

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