Radiation treatment uses high-energy radiation to target and destroy cancer cells by damaging their DNA. While the fundamental process remains consistent, the duration of radiation treatment is not fixed, varying significantly from one individual to another.
Treatment plans are highly individualized, with the overall course spanning from a single session to several weeks or even months, depending on various medical factors. This variation applies to both the length of each individual session and the total duration of the entire treatment course.
Key Factors Influencing Treatment Duration
The type of cancer plays a significant role, as different cancers respond uniquely to radiation. The stage of the cancer also influences the duration, with more advanced or widespread disease potentially requiring longer or more complex treatment regimens.
The primary goal of treatment is another determining factor. If the aim is to cure the cancer, a more intensive and prolonged course is often necessary to maximize cancer cell destruction. In contrast, if the treatment is intended to alleviate symptoms, known as palliative care, the duration is typically shorter, often lasting only a few weeks or even a single session. Patient health and tolerance also factor into scheduling decisions, with plans designed to allow healthy cells time to recover between sessions and manage potential side effects. The specific type of radiation therapy being used, such as external beam radiation or brachytherapy, also dictates the approach and overall duration.
Typical Schedules for Different Therapies
Different types of radiation therapy follow distinct schedules tailored to their delivery methods and treatment goals. Conventional external beam radiation therapy (EBRT), the most common form, typically involves daily sessions, Monday through Friday, for five to eight weeks. This fractionation schedule allows the total radiation dose to be delivered in smaller, manageable portions, giving healthy tissues time to repair. For certain cancers, a shorter course known as hypofractionated radiation therapy is used, delivering higher doses per session over a reduced number of treatments. For instance, breast cancer may be treated with 15 to 18 sessions over three to four weeks, rather than the conventional five to seven weeks, and prostate cancer can also see its treatment time significantly reduced, from nine weeks to as little as one to two weeks, using hypofractionated approaches.
Stereotactic body radiation therapy (SBRT) and stereotactic radiosurgery (SRS) represent highly precise forms of radiation that deliver very high doses to small, well-defined tumors. These therapies significantly shorten treatment duration, often requiring only one to five sessions over one to two weeks. Each SBRT session typically lasts between 30 to 60 minutes.
Brachytherapy, or internal radiation therapy, involves placing radioactive sources directly inside or very close to the tumor. The duration for brachytherapy varies widely, from a single session lasting minutes to implants remaining for several days or even permanently, depending on whether it is high-dose rate (HDR), low-dose rate (LDR), or permanent seed implantation. HDR brachytherapy might involve multiple short sessions over a few days or weeks, while LDR can involve implants staying for a day to a week.
What Happens During a Daily Session
While the overall course of radiation therapy can extend for weeks, the actual time spent receiving radiation during a daily session is quite brief. A typical external beam radiation appointment, from arrival to departure, usually lasts between 10 to 30 minutes. Complex treatments, such as SBRT, might require slightly longer appointment times, sometimes up to an hour.
Much of this time is dedicated to careful preparation and safety checks rather than active delivery of radiation. Upon entering the treatment room, patients are precisely positioned on the treatment table, often using specialized molds or immobilization devices to ensure they remain still and in the exact same position for each session. Imaging, such as a low-dose X-ray or mini CT scan, is frequently performed immediately before treatment to verify position and tumor location. Once positioning is confirmed, therapists leave the room, monitoring the patient from a control area. The actual delivery of the radiation beam typically lasts only one to five minutes, and patients do not feel the radiation during treatment, similar to not feeling an X-ray.