Dr Daphne Jo Valmonte-Panganiban, Radiation Oncology Specialist

Snippets from the recent ESTRO 2026 Convention at Stockholm.

A few days of learning, collaboration, and reconnecting with friends and mentors. This year’s meeting showcased exciting advances in AI-assisted radiotherapy, adaptive treatment strategies, ctDNA-guided cancer care, ultra-hypofractionated prostate radiotherapy (2 fractions?!) , and innovations aimed at improving access to high-quality radiation oncology worldwide.

It was wonderful to see old faces and mentors from Princess Margaret Cancer Centre, to name a few Dr. Laura Dawson, Dr. Andrea Bezjak, Dr. Peter Chung, and many colleagues who have inspired my journey.

Meetings like these are a reminder that keeping up with the latest evidence is essential. Every new insight has the potential to improve patient outcomes and bring world-class expertise closer to our local communities.

June is Awareness Month. Recapping this live interview with UNTV and discussing Prostate Cancer Prevention and Detection with Dr Stephen Nazareth plus , as a non-invasive option for treatment of Prostate Cancer for properly selected patients.

PROSTATE CANCER: Prevention, warning signs, and treatment according to medical experts Learn how to spot the warning signs, explore prevention tips, and u...

Why is radiotherapy given in small daily doses instead of one large treatment?

* Allows normal cells to repair between treatments, reducing side effects.
* Makes cancer cells more vulnerable as they move into phases of the cell cycle where radiation works best.
* Improves oxygen supply to the tumor, making the remaining cancer cells easier to kill.
* Allows regeneration of surviving cells during the treatment period.

In simple terms:
Small daily treatments help us maximize cancer control while minimizing damage to healthy tissues, making radiotherapy both safer and more effective.

Why do some patients experience more side effects from radiotherapy than others?

The prescribed dose may be the same, but every patient is different. Anatomy, breast size, skin type, smoking status, medical conditions, and individual tissue sensitivity can all affect how the body responds to treatment.

Modern techniques like FiF, IMRT, and VMAT help reduce side effects, but radiotherapy is never truly one-size-fits-all.

Because in radiation oncology, the prescription may be the same—but the patient’s anatomy tells a different story.

Why Does Breast Size Matter in Radiotherapy?

The Hidden Challenge Behind Breast Treatment Planning

When people think about breast cancer radiotherapy, they often focus on the prescribed dose, treatment technique, or machine being used.

However, one factor that significantly influences treatment planning is something much simpler:

Breast Size

At first glance, two patients may have the same diagnosis, the same stage, and even receive the same prescription dose.

Yet their treatment plans can be completely different.

The reason lies in physics and anatomy.

As breast volume increases, achieving a homogeneous dose distribution becomes more challenging. Larger breasts often present greater variations in tissue thickness across the treatment field. This means that the radiation beam travels through different path lengths before reaching the target.

As a result, certain areas may receive higher doses than intended, creating what planners call:

Hot Spots

These hot spots are regions that receive a dose exceeding the prescribed level, sometimes reaching values that may increase the risk of acute or late side effects.

Historically, this was a common challenge with conventional tangential breast fields. Patients with larger breast volumes were more likely to experience:

- skin reactions,
- breast edema,
- moist desquamation,
- fibrosis,
- and less favorable cosmetic outcomes.

As radiotherapy techniques evolved, new solutions emerged.

The introduction of:

- Field-in-Field (FiF),
- IMRT,
- VMAT,
- and advanced dose optimization

allowed planners to significantly improve dose homogeneity while reducing excessive dose regions.

Today, treatment planning is no longer simply about covering the breast.

It is about finding the optimal balance between:
target coverage
dose homogeneity
organ-at-risk sparing
and cosmetic outcomes

Breast size can also influence other aspects of treatment, including setup reproducibility, immobilization, heart and lung dose, and even the selection of techniques such as Deep Inspiration Breath Hold (DIBH).

This is why two breast cancer patients rarely receive identical plans, even when their diagnosis appears similar.

Because in radiotherapy...

the prescription may be the same,

but the anatomy tells a different story.

References

- Moran MS et al. ASTRO Whole Breast Irradiation Guideline
- Khan FM. The Physics of Radiation Therapy
- ICRU Report 83
- Donovan E et al. Randomized trial of standard 2D radiotherapy versus IMRT in breast cancer.

Accessible, quality radiation treatment ✨ My heart is full 😌

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Come join this live webinar / Q&A this sunday at 6pm

Sumali sa Usapang Cancer with PSMO ngayong April 26 habang tinatalakay namin ang prevention, symptoms, at treatment ng head and neck cancer kasama ang ating mga experts na sina Dr. Ryan Urgel (ENT Specialist), Dr. Daphne Valmonte (Radiation Oncologist), at Dr. Celina Rodriguez (Medical Oncologist).

Ikaw man ay may risk, o may kakilalang cancer patient, huwag palampasin ang pagkakataong ito na magtanong sa ating LIVE Q&A.

Tune in at 6:00 PM dito sa aming page.

In this infographic you have a structured synthesis of current screening recommendations based on official guidance from:

➡️ United States: U.S. Preventive Services Task Force (USPSTF), American Cancer Society (ACS).

➡️ Europe: European Commission (EU Council Recommendations 2022 update), and position statements from European Society for Medical Oncology (ESMO).

➡️ Only population-based screening with sufficient evidence is included.

Tony Leachon

The reason why I do what I do.