Cisplatin Dosing Adjustments Based on Audiology Testing Results
Cisplatin dosing should be withheld or modified when audiology testing demonstrates significant hearing loss, particularly when reaching Chang grade 2a or higher, as this correlates with clinically significant hearing impairment requiring intervention. 1
Understanding Cisplatin Ototoxicity
Cisplatin is a highly effective chemotherapeutic agent but has significant ototoxic effects that can lead to permanent hearing loss. This hearing loss typically:
- Is sensorineural in nature
- Begins in higher frequencies (≥8 kHz) and progresses to lower frequencies
- Is bilateral and symmetrical
- Is dose-dependent and often irreversible 2
- Affects up to 81% of patients receiving high-dose cisplatin 3
Audiology Monitoring Protocol
Pre-Treatment
- Baseline audiometric assessment before initiating cisplatin therapy
- Include high-frequency audiometry (up to 8 kHz or higher when available)
During Treatment
- Audiometric testing before each subsequent dose of cisplatin 4
- Focus on monitoring high frequencies (≥8 kHz) as these are affected first 5
Post-Treatment
- Continue monitoring for delayed-onset hearing loss
- Follow-up audiograms at 3,6, and 12 months post-treatment 6
Dosing Adjustment Algorithm Based on Chang Grading System
The Chang grading system provides a more clinically relevant assessment of cisplatin-induced hearing loss than other systems like CTCAE 1:
| Chang Grade | Hearing Loss | Recommended Dosing Adjustment |
|---|---|---|
| 0 | ≤20 dB at all frequencies | Continue with planned dose |
| 1a | ≥40 dB at 6-8 kHz | Continue with planned dose but increase monitoring frequency |
| 1b | >20 dB and <40 dB at 4 kHz | Continue with planned dose but increase monitoring frequency |
| 2a | ≥40 dB at 4 kHz and above | Consider dose reduction of 25-50% |
| 2b | >20 dB and <40 dB at <4 kHz | Consider dose reduction of 25-50% |
| 3 | ≥40 dB at 2 or 3 kHz and above | Strongly consider dose reduction of 50% or alternative therapy |
| 4 | ≥40 dB at 1 kHz and above | Discontinue cisplatin if possible and switch to alternative therapy |
Critical Decision Points
FDA Label Guidance: According to the FDA label, "Subsequent doses of cisplatin should not be given until an audiometric analysis indicates that auditory acuity is within normal limits." 4
Clinical Intervention Threshold: Chang grade 2a or higher correlates with the need for audiologic intervention and should trigger consideration of dose modification 1
Risk Factors for Increased Ototoxicity:
- Older age
- Higher single dose of cisplatin (more important than cumulative dose)
- Concurrent use of other ototoxic medications
- Pre-existing cardiovascular risk factors (hypertension, hypercholesterolemia)
- Family history of hearing loss 7
Practical Implementation
- Use high-frequency audiometry whenever possible as it provides earlier detection of ototoxicity 2, 5
- Consider peak plasma concentration monitoring when available (ototoxic changes less likely below 1 μg/L) 3
- When significant hearing loss is detected (Chang grade 2a or higher):
- Reduce cisplatin dose by 25-50%
- Consider alternative platinum compounds (carboplatin has less ototoxicity)
- Implement more frequent audiologic monitoring
Common Pitfalls to Avoid
- Inadequate monitoring: Only 39% of patients receive baseline audiometry and only 36% receive post-treatment evaluation 6
- Focusing only on conventional frequencies: High frequencies are affected first and should be monitored 5
- Relying solely on patient-reported symptoms: Objective audiometric testing is essential as patients may not notice early high-frequency hearing loss
- Continuing full-dose cisplatin despite significant hearing loss: This can lead to irreversible hearing impairment affecting quality of life
- Neglecting non-head and neck cancer patients: These patients often receive less audiologic follow-up 6
By implementing systematic audiologic monitoring and appropriate dose adjustments based on the Chang grading system, clinicians can minimize the risk of permanent hearing loss while maintaining effective cancer treatment.