Surviving cancer does not always mean leaving treatment-related health complications behind. Certain cancer treatments can cause silent heart muscle damage, known as cardiotoxicity, whose clinical manifestations of which may not appear until 10 or 20 years after treatment. In the observance of World Heart Day on September 29, the Spanish Society of Nuclear Medicine and Molecular Imaging (SEMNIM) highlighted the role of nuclear medicine in detecting and monitoring this long-term myocardial damage.

Speaking with El Médico Interactivo, part of the Medscape Professional Network, Francisco Sebastián Palacid, MD, coordinator of the Cardiology Working Group at the SEMNIM and nuclear medicine physician at the University Clinical Hospital of Valladolid in Valladolid, Spain, said, “Cardiotoxicity can occur acutely, within the first year after treatment, or late, 10 or 20 years later, especially in those who were treated as children.” For this reason, he emphasized that follow-up should not be limited to the active treatment phase but should continue over time for patients at higher risk.

Primary Care

In response to the question about what warning signs a primary care physician should watch for and how often tests should be repeated after a patient is discharged from cancer care, the specialist emphasized that once patients stop attending regular hospital follow-up appointments, primary care physicians play a key role in detecting late cardiotoxicity.

“A message I’d like to get across loud and clear to my colleagues in primary care is this: Just because a patient is ‘cured’ of cancer doesn’t mean we can forget about their heart. Often, the first person to detect a problem is not us or the oncologist, but the family doctor, because they continue to see that patient year after year once cancer follow-up has ended,” said Palacid.

Patients who have received cardiotoxic drugs or thoracic radiation therapy (RT) should not exhibit seemingly minor symptoms. “I would tell them to pay close attention, above all, to things that seem trivial but, in this context, are not: that the patient begins to feel fatigued during activities they used to do without any trouble, that they feel short of breath when climbing stairs or even when lying down in bed, that their ankles swell, that they experience new palpitations, or that they suddenly gain weight over a few days for no apparent reason, which is usually due to fluid retention,” he said. “Any of these signs, in someone who has received anthracyclines, trastuzumab, or RT to the chest, should raise concern, even if 10 or 15 years have passed since treatment.”

Follow-up should be on the basis of cumulative risk. “If it was low-dose treatment with no other contributing factors, a checkup every 3 to 5 years is usually sufficient. But if we’re talking about someone who received high doses, who combined several cardiotoxic treatments, who underwent thoracic RT, or who was treated as a child, then I would be much stricter: an annual checkup, or at most every 2 years, with an echocardiogram or, if available, a radionuclide scan,” he said. He also noted that these questions did not require a cardiologist to ask. “Simply by asking these patients about these symptoms at every checkup, we can often prevent them from coming to us with established heart failure.”

Risk Profile

However, not all patients require the same level of monitoring. Women with breast cancer treated with anthracyclines in combination with trastuzumab are at particularly high cardiac risk, as are patients with lymphoma treated with regimens that include anthracyclines and thoracic RT. Children and adolescents treated for leukemia or sarcoma are considered the most vulnerable group because they receive high doses of chemotherapy while their hearts are still developing. “That is why these patients should be monitored for decades,” said Palacid.

Among the diagnostic tools, radionuclide ventriculography, also known as multigated acquisition scanning, stands out because it allows myocardial function to be measured before, during, and after chemotherapy with high reproducibility. SEMNIM has warned of substantial disparities in access to these techniques among Spain’s autonomous communities and even among hospitals within the same community. Some centers have modern equipment and perform a high volume of studies, whereas in others, testing has declined to almost negligible levels, forcing some patients to travel to other cities.

When asked about this lack of resources, Palacid discussed the situation at medium-sized hospitals: “I prefer not to single out specific hospitals or communities, because I don’t think that’s a productive line of discussion here, and besides, there are differing perspectives on this issue even within the profession itself. What I can say, in general terms, is that the problem is not uniform: It primarily affects medium-sized hospitals, which are not large referral centers but also not small regional facilities with no resources at all. It is in these intermediate-sized hospitals where, if a specialist with experience in nuclear cardiology retires or leaves, that position is often not filled by someone equally trained in this subspecialty, and the technique gradually fades away through disuse, not because a decision is made to explicitly shut it down.”

Several measures are needed to address this gap, he said. “I believe several things are needed: to update equipment in facilities where it has become obsolete, to ensure that when a specialist trained in this area leaves, they are replaced by someone equally qualified, and above all, to update the specialty’s training programs, which have not been thoroughly reviewed for quite a few years. And I would add something that I think is often overlooked: establishing common protocols among the autonomous communities, so that access to these tests does not depend so much on the patient’s postal code.”

Impact on the Volume of Patient Care

Regarding the number of patients in Spain who received cardiac monitoring using nuclear medicine each year, Palacid referred to data from the scientific society’s records.

“There is a survey conducted by the SEMNIM Working Group several years ago, in which 42 centers from all over Spain participated, and which recorded more than 40,000 nuclear cardiology patients in 1 year, with most of those studies focused on assessing blood flow to the heart. This data is somewhat outdated, and the current figures have likely changed, so I prefer not to venture an exact figure for today,” Palacid said.

Despite this, he emphasized the continued importance of these techniques in clinical practice: “I can say that we’re talking about tens of thousands of patients a year in Spain who benefit from this technique, not to mention more recent applications such as cancer monitoring or the diagnosis of amyloidosis, which are on the rise.”

This article was translated from El Médico Interactivo.