SRS and SRT: Stereotactic RadioSurgery and RadioTherapy

What are SRS and SRT?

Stereotactic Radiosurgery (SRS) and Stereotactic Radiation Therapy (SRT) are advanced radiation treatments designed to deliver high-dose radiation to a precise, focused area. These techniques effectively control tumor growth by either killing cancer cells or inhibiting their ability to multiply.

• SRS is a single, high-dose treatment
• SRT is delivered in smaller doses over multiple sessions, making it gentler on surrounding healthy tissue

Both techniques are used to treat localized tumors, particularly in the brain, and are increasingly employed in other parts of the body through Stereotactic Body Radiation Therapy (SBRT).

How do SRS and SRT Work?

SRS and SRT use ultra-focused radiation to target tumors with sub-millimeter accuracy while protecting healthy tissue.

• Specialized Positioning Devices: Patients are fitted with custom masks or positioning molds during a CT scan to ensure precise alignment during treatment.
• Advanced Imaging: CT or MRI scans are taken before treatment to guide the radiation beams. During the procedure, the beam adjusts to the tumor’s shape, ensuring precise delivery.

Treatment Process

Mask and Positioning Device Creation

• At your first appointment, a custom mask or positioning device is made.
• Made of aquaplast, the material is warmed, molded to your head and neck, and hardened for daily use.
• The process is comfortable and takes about an hour.

Preparing for Treatment

• CT and MRI scans are necessary before treatment to gather detailed images of the tumor.
• These scans may be scheduled a few days or a week prior, and an additional planning scan will occur with your mask on the day of preparation.

During Treatment

• You’ll lie on a treatment table with your mask securing your position.
• Radiation therapists will ensure you’re comfortable using knee pillows and blankets.
• The radiation delivery is fully computerized and monitored from outside the room. You’ll be able to communicate with the team through an intercom.
• No physical sensation accompanies the radiation, but you may hear or see the equipment repositioning.
• Most treatments take about 10 minutes, though the entire session, including setup, lasts 30–60 minutes.

How Many Treatments Will I Need?

Your radiation oncologist will determine the number of treatments based on your condition. Treatments are typically scheduled daily, Monday through Friday, and your schedule will be personalized for your needs.

Side Effects

Most patients experience minimal side effects, but some may notice temporary skin patterns from the mask, mild headaches, fatigue or gastrointestinal discomfort. Always inform your treatment team of any concerns so they can address them promptly.

After Treatment

At your last session, your nurse will provide follow-up instructions and schedule a post-treatment appointment. Follow-up may include tests like CT or MRI scans to monitor progress.

SRS and SRT at Stony Brook Medicine offer patients advanced, precise treatments developed for comfort, effectiveness and minimal disruption to daily life. By leveraging cutting-edge technology and a multidisciplinary team approach, we aim to provide the best quality care and outcomes.