Cisplatin chemoradiation is a standard approach to cancer treatment that combines the platinum-based chemotherapy drug, Cisplatin, concurrently with daily external beam radiation therapy. The primary goal of this combined treatment is to maximize the destruction of localized or locally advanced cancer cells. Clinicians aim to achieve a higher rate of tumor control than either modality could accomplish alone. This approach is frequently utilized when high efficacy is required while attempting to preserve the function of nearby organs.
The Synergy of Concurrent Chemoradiation
The success of combining Cisplatin with radiation therapy is rooted in radiosensitization. Cisplatin acts not only as a direct cancer cell killer but also enhances the tumor’s vulnerability to the radiation beams by interfering with the cell’s ability to repair radiation damage.
Cisplatin forms covalent cross-links within the cancer cell’s DNA, creating structural distortions. When radiation induces further damage, these Cisplatin-DNA adducts effectively jam the cellular machinery responsible for DNA repair, particularly the Non-Homologous End Joining (NHEJ) pathway. By inhibiting this repair mechanism, the drug converts repairable radiation damage into permanent, lethal damage. Cisplatin also causes a temporary accumulation of cancer cells in the G2/M phase of the cell cycle, when cells are naturally most susceptible to radiation. This dual action significantly amplifies the therapeutic impact of the radiation dose.
Common Cancers Treated
Concurrent Cisplatin chemoradiation is the standard of care for several types of locally advanced cancers. The combination is most commonly used for head and neck cancers, particularly those affecting the larynx, pharynx, and oral cavity. This strategy is often chosen to eradicate the tumor while avoiding extensive surgery that could compromise a patient’s speech or swallowing function.
Another primary application is in the treatment of locally advanced cervical cancer, where combined therapy has demonstrated improved survival rates compared to radiation alone. Specific types of non-small cell lung cancer (NSCLC) that are locally advanced also frequently benefit from this combined modality. The decision to use this treatment depends on the cancer’s stage, location, and the patient’s overall health status.
Treatment Schedule and Delivery Logistics
Receiving concurrent chemoradiation involves a structured schedule over several weeks. Radiation therapy is typically delivered five days a week, Monday through Friday, often spanning five to seven weeks. The chemotherapy portion is precisely timed to coincide with the radiation to maximize the radiosensitization effect.
Cisplatin is administered intravenously in one of two main schedules, depending on the cancer type and patient tolerance. One schedule involves a high dose given once every three weeks, while the other uses a lower dose delivered weekly throughout the entire course of radiation. Each infusion requires an intravenous drip and can take several hours, including necessary pre- and post-infusion fluids.
The process is managed by a multidisciplinary care team, including a medical oncologist, a radiation oncologist, and specialized nurses. Frequent monitoring is required, with blood work often checked weekly to assess kidney function and blood cell counts. This oversight allows the team to make real-time adjustments to the treatment plan, such as modifying the Cisplatin dose or delaying treatment if the patient shows signs of intolerance.
Managing Specific Toxicity
The combination of Cisplatin and radiation creates an intense side effect profile that requires proactive management. Cisplatin is well-known for its systemic toxicities, including nephrotoxicity (damage to the kidneys). To prevent this, patients receive extensive intravenous hydration before and after each infusion to help flush the drug from the system.
Another significant systemic concern is ototoxicity, which can manifest as permanent hearing loss or persistent ringing in the ears (tinnitus). Since there is no specific treatment to reverse this damage, hearing is monitored before and during treatment. The drug also commonly causes significant nausea and vomiting, which is managed with a strict regimen of antiemetic medications given before and after the infusion.
When combined with radiation, these systemic effects are compounded by localized side effects specific to the treatment area. For head and neck cancers, concurrent therapy often leads to severe mucositis—painful inflammation and ulceration of the mucous membranes in the mouth and throat. This localized reaction can make swallowing extremely difficult, frequently requiring nutritional support through a feeding tube to maintain weight and strength.