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Christien Kluwe, MD, PhD
Call (210) 450-1000

The information below is for general educational purposes only and is not a substitute for professional medical advice. Please discuss your specific diagnosis and treatment with Dr. Kluwe or your care team.

Topic 01

Understanding Radiation Therapy

Radiation therapy uses high-energy beams — most often X-rays — to damage the DNA of cancer cells so they can no longer grow or divide. Over time, the body clears these damaged cells. Radiation can be used on its own or alongside surgery, chemotherapy, or other treatments, depending on the type and stage of cancer.

Because radiation affects both cancerous and nearby healthy cells, modern techniques are designed to focus the dose as precisely as possible on the target area while limiting exposure to surrounding tissue. The specific approach used depends on your diagnosis, anatomy, and treatment goals.

Two general types

External beam radiation therapy delivers radiation from a machine outside the body.

Brachytherapy places a radiation source inside or near the tumor itself.

Topic 02

Preparing for Your First Visit

Your first consultation is a chance for Dr. Kluwe to understand your diagnosis and history, and for you to ask questions and understand your options.

  • A list of current medications
  • Relevant imaging and pathology reports
  • A written list of your questions
  • A family member or friend, if you’d like support

Topic 03

Managing Side Effects

Side effects vary based on the area treated, the dose, and individual factors. Your care team will discuss what is realistic to expect for your specific treatment plan.

Fatigue

Many patients experience some tiredness during treatment. Pacing activity and prioritizing rest can help.

Skin & Tissue Changes

Skin near the treatment area may become sensitive. Your team will provide specific skin care guidance.

Area-Specific Effects

Effects vary by treatment site — your team will explain what to watch for based on your plan.

Topic 04

Nutrition & Wellness During Treatment

Maintaining good nutrition and gentle activity, as tolerated, can support your body during treatment. Your appetite or energy may fluctuate — this is common, and your care team can connect you with additional support if needed.

Topic 05

Emotional & Support Resources

A cancer diagnosis affects more than the body. If you would like support — whether counseling, a support group, or resources for family members — please ask your care team. They can help connect you with resources available through the Mays Cancer Center.

Topic 06

Glossary of Common Terms

EBRT

External Beam Radiation Therapy — radiation delivered from a machine outside the body. This is in comparison to brachytherapy, where the radiation is implanted directly into the tumor.

IMRT

Intensity-Modulated Radiation Therapy — a technique that shapes radiation dose to match the target. This includes techniques such as Volumetric Modulated Arc Therapy where the linear accelerator rotates 360 degrees around the patient, delivering a continuous, precisely shaped dose of radiation to the tumor while avoiding nearby healthy tissue.

Linear Accelerator

Often called a "linac" for short. This machine uses electricity to speed up subatomic particles to create a beam of high-energy X-rays.

IGRT

Image-Guided Radiation Therapy — using imaging before or during treatment to improve accuracy. Often this involves a rapid CT-scan while the patient is on the treatment table to allow millimeter shifts to ensure the tumor is well-targeted.

SBRT / SRS

Stereotactic Body Radiation Therapy / Stereotactic Radiosurgery — highly focused, high-dose radiation given in few sessions.

Brachytherapy

Internal radiation therapy, with a radiation source placed in or near the tumor.

Simulation

A planning appointment, often including a CT scan, used to design your treatment before it begins.

Dosimetrist

A member of your treatment team who specializes in designing the treatment plan, using advanced computer software to map out 3D radiation plans and instruct the linear accelerator to achieve this.

Radiation Therapist

A medical professional who operates the linear accelerator, ensures your appropriate positioning for each treatment, and keeps a daily detailed log of treatment.

Adaptive Radiotherapy

An approach where your treatment plan is re-optimized partway through your course, using updated imaging to account for anatomical changes.

Radiopharmaceutical Therapy

A treatment that uses a radioactive medication, given systemically (such as by injection), to treat cancer that has spread to multiple sites in the body.

Growing Resource

Patient Education Library

Beyond the topics above, we’re building a growing library of short, focused articles — added to over time — covering specific questions and topics patients ask about most.

Browse the library

New topics added regularly

Check back as new articles are added — or bring a topic you’d like covered to your next visit.

Still have questions?

Our team is happy to talk through anything you’ve read here in more detail.