PROTECT

When the heart is the organ to protect

Esophagus, lung, mediastinum, breast. Some treatments cannot be performed if the tumor is too close to the heart. CardioKit monitors the heart position to allow these treatments to be performed safely.

01 / Why it matters

Heart dose is not free

Dose delivered to healthy heart tissues have negative impacts years later as coronary disease, heart failure and valve disease.

7.4 %more major coronary events per gray of mean heart dose, after breast radiotherapy*
RTOG 0617heart dose predicted survival in locally advanced lung cancer*
Decadesof excess cardiac risk in mediastinal lymphoma survivors*
4.8 Mnew lung and breast cancers a year, both may have tumors next to the heart*

Motion management The practice today*

CardioKit heart monitoring What we aim for**

SurrogateChest surface or marker detection: breathing is tracked but the heart position is inferred*
Heart positionLive ultrasound of the wall nearest the field, no imaging dose is delivered**
Single CTThe heart position is fixed at planning, larger marging are used to cover the excursions and drift*
Live monitoringThe heart position is checked live against the tolerance margin, the clinician can monitor the treatment**
Breath-holdBreath-hold spares the heart only for patients who can hold. Breath-hold is not easily reproducible*
Free breathingThe patient can breathe normally. Expiration and inspiration positions are more reproducible while free breathing**

Darby, NEJM 2013 (7.4 % per gray), Bradley, Lancet Oncology 2015 (RTOG 0617), van Nimwegen, JCO 2016 (Hodgkin survivors), GLOBOCAN 2022 (lung 2.5 M, breast 2.3 M), IAEA DIRAC, PTCOG (May 2025), Dataintelo (motion management), AAPM TG-76 (respiratory motion management), Bergom, Front Oncol 2018 (breath-hold for cardiac sparing). More on the evidence page.
The heart-monitoring column is what EBAMed designs CardioKit against, not clinical results.

02 / Heart monitoring

Watch the heart Hold the beam

Here CardioKit tracks no target inside the heart. It tracks the heart itself: the wall nearest the field, against where the plan put it.

HEART TRACKED HEART TOLERANCE ENVELOPE TUMOR TARGET VOLUME BEAM
Schematic. The heart position is monitored.
The clinicial is informed if the heart moves out of the configured window.

03 / The heart is in the way

Six situations

Where is the heart right now, and is it too close to the planned treatment field?

What we aim for next

ESOPHAGUS

Mid-esophageal tumors

The mid-esophagus runs behind the left atrium. Chemoradiation puts the back of the heart in the high-dose region. The heart rubs against the esophagus with every beat.

LUNG · CENTRAL

Central tumors near the heart

Hilar tumors, and tumors against the pericardium, sit in the steepest part of the dose gradient. Stereotactic doses here are capped by what the heart and great vessels can take.

LUNG · LOWER LOBE

Lower-lobe tumors beside the heart

The lower lobes move most with breathing. The heart rests on them. Two motions, two organs, one margin trying to cover both.

MEDIASTINUM

Mediastinal lymphoma

Young patients, long survival, and a field that wraps around the heart. Late cardiac disease is a leading cause of death in long-term survivors.

MEDIASTINUM

Thymoma and thymic tumors

The thymus lies on the front of the heart. Radiotherapy to the anterior mediastinum shares its field with the right ventricle and the coronaries.

BREAST

Left breast, breath-hold not possible

Breath-hold is the sparing standard for left-sided breast. For patients who cannot hold, heart monitoring is a way to know, and cap, what the heart gets.