Palliative radiotherapy (PRT) is a specialized application of radiation treatment for individuals dealing with advanced or metastatic cancer. Unlike curative treatment, PRT’s sole objective is to improve quality of life by managing symptoms caused by the tumor. The therapy delivers high-energy X-rays to shrink the tumor or slow its growth, reducing pressure on nearby tissues and nerves. PRT is a component of comprehensive palliative care, focusing on comfort and relief when the cancer is no longer curable.
Primary Goals of Palliative Radiotherapy
PRT is used when a localized symptom significantly impacts daily functioning and comfort. The most frequent and successful use is controlling pain caused by bone metastases, where cancer has spread to the skeleton. Clinical studies show PRT provides effective pain relief for 60% to 80% of patients with painful bone lesions, with complete relief achieved in about 30% to 40% of cases.
The therapy is also used for neurological issues, such as when a tumor compresses the spinal cord, which is a medical emergency. Radiation quickly shrinks the mass, relieving pressure to prevent irreversible paralysis or loss of function. PRT also manages symptoms from brain metastases, reducing tumor size to alleviate pressure that causes severe headaches, nausea, or seizures.
PRT is utilized to control bleeding and relieve obstruction. Tumors in areas like the lung, bladder, or rectum can cause persistent bleeding, which radiation manages by destroying fragile blood vessels within the cancerous tissue. When a tumor blocks a hollow organ, such as the windpipe or gastrointestinal tract, a short course of radiation shrinks the mass to open the passage and relieve difficulty breathing or swallowing. Symptom improvement is typically seen within a few weeks, offering durable relief that can last for months.
Treatment Schedules and Delivery
Palliative radiotherapy is designed to minimize inconvenience and treatment burden for the patient. Unlike curative radiation, which is delivered in small daily doses over five to nine weeks, PRT employs hypofractionation. This approach uses larger radiation doses per session, resulting in a significantly shorter overall treatment course.
Many patients receive treatment in a single fraction of 8 Gray (Gy), or a short series such as 20 Gy in five fractions over one week, or 30 Gy in ten fractions over two weeks. The goal of these compressed schedules is to achieve rapid, effective symptom control with the fewest possible hospital visits. Using fewer, higher-dose fractions ensures the patient spends less time commuting and lying still for treatment.
Deciding When Treatment is Not Appropriate
The decision to pursue palliative radiotherapy requires careful consideration of whether the potential benefit outweighs the burden of treatment. This balance is delicate when a person’s life expectancy is very limited. If a patient is expected to live only for a few weeks, the time spent traveling to and recovering from treatment may exceed the time available for symptom relief.
Medical teams assess a person’s functional status to determine their ability to tolerate and benefit from the treatment. Patients who are very weak, require constant assistance, or spend most of their time in bed often find the travel and the need to remain still too taxing. In these instances, the treatment itself can increase suffering without providing adequate gain.
Side effects must also be weighed against the relief. While PRT aims for minimal toxicity, side effects like general fatigue or a temporary worsening of pain, known as a pain flare, can occur. If the anticipated relief is marginal or short-lived, and the side effects are severe, the intervention is deemed inappropriate.
Prior radiation history in the target area is another limiting factor because normal tissues have a lifetime limit for how much radiation they can safely tolerate. Delivering a second course of radiation to the same area significantly increases the risk of severe, permanent damage to surrounding organs and structures. Open communication with the oncology team about goals of care is necessary to ensure the intervention aligns with the patient’s desire for comfort and quality of life.