Definitive Chemoradiation in a Patient Who Is an Imperfect Cisplatin Candidate

Standard of care, and its price. Concurrent high-dose cisplatin 100 mg/m² every 3 weeks with radiotherapy has the strongest randomized evidence for locoregional control and survival in locally advanced head and neck cancer. That makes it the default - but "default" is not the same as "indicated for everyone," and this patient sits in the gray zone.

Where he falls short of the trial population:

• Renal function: estimated CrCl 48 mL/min is below the commonly used threshold of 60 mL/min for 100 mg/m² cisplatin. Three cycles of 100 mg/m² delivers ~300 mg/m² cumulative, and cisplatin nephrotoxicity is dose-cumulative.
• Ototoxicity stacking: pre-existing high-frequency hearing loss plus diabetes both increase risk of clinically meaningful hearing decline, which is irreversible and affects function and cognition.
• Neuropathy: diabetic peripheral neuropathy is a competing risk for cisplatin sensory neurotoxicity.
• Logistics matter, but not in the direction people assume: high-dose cisplatin requires only 3 visits (plus hydration), whereas weekly regimens require 6–7. For a man driving 3 hours round trip, the every-3-week schedule is actually the less burdensome option if he can tolerate it.

Reasonable alternatives and their trade-offs:

1. Weekly cisplatin 40 mg/m² - lower peak exposure and lower cumulative dose (~200 mg/m²), generally better tolerated renally, but the evidence base is weaker than high-dose and it requires more visits and more mucositis management.
2. Weekly carboplatin AUC 1.5–2 - substantially less nephrotoxic and ototoxic; acceptable when cisplatin is genuinely unfit, but considered potentially less effective, so it is a compromise, not an equivalent.
3. Cetuximab with radiotherapy - reserve for patients in whom platinum is truly contraindicated; do not present it as a like-for-like swap.
4. Radiotherapy alone - the fallback if he declines or cannot tolerate any systemic agent.

Counseling. Frame it as a trade-off between a modestly higher chance of cure and a meaningful risk of permanent hearing loss, worsening neuropathy, or renal injury. A concrete sequencing suggestion: offer high-dose cisplatin with an aggressive renal-protection protocol (1 L normal saline pre-hydration, no mannitol required, magnesium and potassium repletion) if he accepts audiometric monitoring and stopping rules - or weekly cisplatin if he prioritizes avoiding hearing and kidney injury. Document the discussion either way.

Write these into the plan prospectively; deciding retrospectively after a creatinine bump invites continuation by momentum.

Baseline (before cycle 1):

• Cockcroft-Gault CrCl, magnesium, potassium, and a repeat audiogram if the prior one is >6 months old.
• Document baseline neuropathy grade and performance status.

Before each cycle:

• Creatinine/CrCl, magnesium, potassium, CBC, and a symptom screen for tinnitus, hearing change, numbness, and oral intake.

Stopping or switching rules (state them explicitly):

• CrCl falls below 50 mL/min, or creatinine rises ≥25–30% above baseline at the pre-cycle check → switch to carboplatin or weekly cisplatin rather than dose-reducing high-dose cisplatin.
• Magnesium <1.5 mg/dL unresponsive to repletion, or any grade ≥2 nephrotoxicity → switch.
• New symptomatic hearing loss or tinnitus, or grade ≥2 ototoxicity on audiogram → stop platinum.
• Grade ≥2 sensory neuropathy → stop platinum.
• Grade ≥3 mucositis with inability to maintain hydration or weight, or an unplanned admission → reassess before the next cycle rather than proceeding automatically.

Why this framing. The decision is not "cisplatin or not" made once at the start; it is a conditional plan with pre-agreed triggers. That avoids both premature abandonment of a curative regimen and the common failure mode of pushing a third cycle through a rising creatinine in a patient who cannot afford the renal hit.