World Cancer Day 2024: Knowing how chemotherapy and radiation therapy differ from one another

Every year on February 4, people around the world observe World Cancer Day. The purpose of the day is to raise awareness about cancer. Cancer is a broad category of illnesses that can impact any organ or tissue in the body. It is used to describe the uncontrollably dividing cells that grow abnormally. Radiation therapy, chemotherapy, surgery, hormonal therapy, targeted therapy, and immunotherapy are the main cancer treatment modalities. Multimodality care is becoming more and more common in cancer treatment.

There are two different approaches to treating cancer: chemotherapy and radiotherapy. However, patients and the general public may frequently become confused by these similar-looking terms because they both have a similar suffix and are used for cancer management.

Chemotherapy: Systemic medication

Medication is given orally or intravenously during chemotherapy. The goal is to target cancer cells by distributing the medication throughout the body. Because it can reach cancer cells both locally and at distant sites, this treatment is also known as a systemic approach.

Radiation Therapy: Targeted treatment

Radiation therapy treats the local site with extreme focus. It functions by causing damage to cancer cells’ DNA. High-energy rays or particles are precisely aimed at the tumor or other vulnerable areas during radiation treatment. It’s a focused, localized process that mainly targets the area of the body that receives the radiation treatment.

Radiation therapy can be administered alone, in conjunction with surgery or chemotherapy, or, in more advanced cases, as palliative care, depending on the location of the tumor. At some point during the course of their total treatment, radiation therapy would be necessary in between 60% and 70% of all cancer cases.

Treatment duration and techniques

Chemotherapy is usually administered in cycles, i.e., a two-week cycle would consist of a dose given every two weeks. Chemotherapy regimens can range from two to six cycles. A single medication or a combination of medications can be used in a standard chemotherapy infusion cycle.

Radiation therapy, in contrast, is typically administered every day (aside from weekends). Radiation treatments typically last between three and six weeks. But the whole course of treatment can be finished in one to seven days with stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS). Patient populations with very early or localized disease are among the few who can benefit from the latter techniques.

Advantages and side effects

Each treatment has a unique set of benefits and side effects. Radiation therapy can be used to both shrink tumors prior to surgery and is frequently used as a curative treatment for localized cancers. In numerous instances, it is also utilized following surgery to address microscopic diseases that are invisible and present in the tumor bed or its surrounding areas. It may also result in changes in skin tone, weariness, and skin irritation as side effects. Notably, its effects (or side effects) are negligible outside of the prescribed area. Additionally, the organs nearby and the area being treated would determine the side effects. Contemporary radiation therapy employs methods like CT scan-based image guidance and has become extremely conformal, closely encircling the target area.

Determining the best course of treatment

Radiation therapy, chemotherapy, surgery, or a combination of these will be chosen depending on the type of cancer, its stage, and the specific characteristics of the patient. The best course of action in each situation must be determined by speaking with a licensed medical expert. The majority of hospitals have set up tumor boards where a team decides on the best course of action and sequence of care for a specific patient and disease site.

Chemotherapy and radiation therapy are useful methods for managing cancer. Nonetheless, a skilled oncology team is the best source of guidance for their administration and use. Notably, technological advancements have greatly decreased the side effects of radiation therapy and chemotherapy, which makes cancer treatment considerably more comfortable for both the patient and the physician.