Clinical Oncology with Dr uzair

Muscle invasive bladder cancer. T2N1 (Transitional cell carcinoma)

The Role of Immunotherapy and ADC in bladder Cancer

Every Oncologist should know about Her-2 testing in Locally Advance Urothelial Cancer

🚀 The Evolution of HER2-Positive Breast Cancer Treatment (2005–2026)

"The greatest power in oncology is not just treating cancer, but preventing the next one."

Something about Her+2 +ve Breast Cancer

⚔️ The eternal battle in Radiation Oncology:

6 MV vs 15 MV

Every treatment planner has faced this dilemma at least once!

🔹 6 MV — excellent for most clinical situations, better dose conformity, and no neutron contamination.

🔹 15 MV — offers greater pe*******on for deep-seated targets and large patients, but at the cost of increased neutron production.

The truth? There is no single "best" energy.

🎯 The ideal beam energy is the one that achieves optimal target coverage while minimizing dose to organs at risk.

In Radiation Oncology, treatment is not about choosing sides—it's about choosing what is best for the patient.

Catalyst™
The Technology That Watches the Patient Without Touching Them

Imagine treating a patient...

Without using X-rays.

Without adding extra imaging dose.

Without placing any device on the patient's body.

And yet...

You know if the patient moves by less than a millimeter.

It sounds futuristic.

But this is exactly what Catalyst™ Surface Guided Radiation Therapy (SGRT) was designed to do.

---

For decades, patient positioning in radiotherapy relied mainly on skin tattoos, room lasers, and image guidance such as CBCT.

These methods remain highly effective.

However, they all answer the same question:

"Where was the patient when we took the image?"

Catalyst asks a different question:

"Where is the patient right now?"

That difference changes everything.

---

Catalyst uses a set of high-resolution cameras and structured light projectors to create a three-dimensional map of the patient's body surface.

This surface is continuously compared with the reference surface obtained during CT simulation.

If the patient's position changes...

Even by a few millimeters...

The system detects it immediately.

There is no need to touch the patient.

No additional radiation is required.

Only continuous optical monitoring.

---

One of the greatest advantages of Catalyst is that monitoring does not stop after setup.

It continues throughout the entire treatment.

If the patient coughs...

Moves an arm...

Raises the shoulders...

Or changes position during irradiation...

The system detects the motion instantly.

In many departments, the treatment beam can even be paused automatically until the patient returns to the correct position.

This transforms radiotherapy from image-guided treatment into surface-guided treatment.

---

Catalyst has become particularly valuable in breast radiotherapy.

Many left-sided breast cancer patients are treated using the Deep Inspiration Breath Hold (DIBH) technique.

During a deep breath, the heart moves farther away from the chest wall, increasing the distance between the heart and the treatment field.

This allows the radiation dose to the heart to be significantly reduced while maintaining excellent target coverage.

But DIBH is only effective if the patient reproduces the same breath hold every day.

Catalyst makes this possible.

The system continuously monitors the patient's breathing and allows radiation delivery only when the chest surface is within the predefined gating window.

If the breath hold changes...

The beam stops automatically.

No manual intervention is required.

---

Another important advantage is patient comfort.

Traditional skin tattoos have been part of radiotherapy for decades.

With modern SGRT workflows, many centers can reduce or even eliminate permanent tattoos for selected treatment sites.

For many patients, this improves the overall treatment experience without compromising accuracy.

---

Does this mean Catalyst replaces CBCT?

No.

This is one of the biggest misconceptions.

Catalyst and CBCT are not competitors.

They complement each other.

CBCT provides information about the internal anatomy—the tumor, bones, and organs.

Catalyst provides information about the external body surface and real-time motion.

One sees inside the patient.

The other watches the patient continuously from the outside.

Together, they provide a higher level of treatment accuracy than either system alone.

---

Perhaps the most impressive thing about Catalyst is that it reminds us of an important truth in modern radiotherapy:

Accuracy is not achieved by taking one perfect image.

Accuracy is achieved by ensuring that the patient remains in the correct position from the first second of treatment until the very last Monitor Unit is delivered.

Sometimes...

The safest beam is not the one with the highest energy.

It is the one delivered to a patient who never moved.

References

- C-RAD Catalyst™ Clinical Documentation
- ESTRO Guidelines on Surface Guided Radiation Therapy (SGRT)
- AAPM Task Group 302: Surface Guided Radiation Therapy
- Miften M, et al. Surface Guided Radiation Therapy: Current Status and Future Directions

Updates in Oncology