Dosimetry-Guided Theranostics
Radiopharmaceutical Dosimetry: What it Is, and Why it Matters for Your Treatment
At United Theranostics, we don’t assume your dose. We do everything we can to minimize the impact that our radiopharmaceutical therapy has on our patient’s healthy cells. This methodology, called dosimetry, relies on medicine that sits at the intersection of the latest in medical imaging technology, artificial intelligence, and a very human approach to patient care.
Quick Summary
Radiopharmaceutical dosimetry uses quantitative SPECT/CT imaging to help nuclear oncology physicians evaluate how treatment distributes through the body, how tumors absorb therapy, and how healthy organs are exposed.
Section 1 — Definition
What is dosimetry in radiopharmaceutical therapy?
Dosimetry is the science of measuring the radiation dose absorbed by tissue after a radiopharmaceutical treatment is administered. In other words, it tells Nuclear Oncologists how much of the therapy has reached your tumor, as well as how much has reached your healthy organs.
The dose of most cancer treatments is determined by the patient’s body weight, or in some cases a standard dose based on the averaged results of clinical trials. Radiopharmaceutical dosimetry goes further, using post-treatment imaging to measure what actually happened inside your body, not what a population average predicts.
What makes our treatments very unique and special is the fact that we really manage and plan the treatment based on the imaging. It is very different than other types of cancer treatments, and that is what makes theranostics unique.
— Dr. Michael A. Morris, MD, MS, DABR, DABNM, DCI, Nuclear Oncologist & Co-Founder, United Theranostics
Section 2 — Differentiation
Why fixed-dose treatment isn’t enough
Two patients with the same administered radiopharmaceutical can respond very differently to the same dose. Kidney function, body composition, and tumor targeted expression among other patient-specific physiology can affect how a radiopharmaceutical is absorbed.
One-Size-Fits-All Approach:
(treatment management without radiopharmaceutical dosimetry)
This approach does not account for patient-specific factors.
Personalized Nuclear Oncology
(radiopharmaceutical dosimetry-aware treatment management)
Patient-specific radiopharmaceutical treatment plan accounting for personalized physiological differences in the overall treatment plan.
Why it matters
Risks related to radiopharmaceutical therapy relate to absorbed dose to various healthy organs, which varies from patient-to-patient. Radiopharmaceutical dosimetry can only be obtained within a short time after administration, or else this critical information regarding the patient’s treatment is lost. This information is useful to optimize their future treatment plan and minimize risks.
Section 3 — Clinical Process
How dosimetry-guided treatment works at United Theranostics
Each treatment cycle combines therapy with quantitative imaging, so we know what the therapy did, not just what it was supposed to do.
Pre-treatment Imaging
Helps nuclear oncologists to create a map of the disease burden before a cycle begins.
Radiopharmaceutical Administration
The treatment is administered in an outpatient setting at one of our treatment centers.
Post-treatment imaging
After treatment has occurred, SPECT/CT imaging allows the United Theranostics team to see how the patient’s body has distributed the treatment.
Radiopharmaceutical Dosimetry Assessment
We calculate how much of the dose has been delivered to tumor tissue versus healthy organs, informing future treatments.
Section 4 — Treatments
Radiopharmaceutical dosimetry is available at United Theranostics
United Theranostics is able to assess radiopharmaceutical dosimetry for patients receiving treatments at our facilities. Before receiving radiopharmaceutical therapy, patients may want to know if their Nuclear Oncologist or theranostics treatment center is able to assess radiopharmaceutical dosimetry.
Lutathera (Lu-177 DOTATATE)
For somatostatin receptor-positive neuroendocrine tumors.
Section 5 — FAQ
Frequently Asked Questions
Does every theranostics treatment provider use radiopharmaceutical dosimetry?
No. Radiopharmaceutical dosimetry requires specially calibrated quantitative SPECT/CT imaging equipment and experienced Nuclear Oncology Physicians to assess and evaluate quantitative results within a short period after treatment. Most treatment centers offering radiopharmaceutical therapy do not have the capability nor the experience to assess radiopharmaceutical dosimetry, though this assessment is available at United Theranostics Nuclear Oncology Centers of Excellence.
Will Radiopharmaceutical Dosimetry Change My Treatment Plan?
It can. Radiopharmaceutical dosimetry informs how your healthy organs are exposed to theranostics treatments, which can help your treating Nuclear Oncology Physician to better tailor your personalized treatment plan.
What Is Quantitative SPECT/CT And How Does It Differ From PET/CT?
A PET/CT detects positron emissions from a diagnostic radiotracer to very sensitively detect disease features or patient-specific disease physiology. United Theranostics' quantitative SPECT/CTs are specially calibrated, even incorporating NIST-traceable sources to accurately measure emitted photons from radiopharmaceutical therapy treatments. Activities are quantified in Bq/mL for each voxel and personalized contours are created for organs and tumors. Absolute absorbed dose throughout various regions of interest is evaluated.
Does Radiopharmaceutical Dosimetry Add Time To My Visits?
Post-treatment SPECT/CT imaging may take place after radiopharmaceutical administration or short follow up visits. While the imaging itself does not take long, it often necessitates additional short appointments within a week or two of your treatment, which are instrumental in assessing how your body absorbs and excretes the treatment.
Is Radiopharmaceutical Dosimetry Covered By Insurance?
Coverage varies by plan, indication and medical necessity. United Theranostics handles insurance eligibility and prior authorization.
Talk to a Nuclear Oncologist
Dosimetry-guided radiopharmaceutical therapy is available at all United Theranostics locations. Speak with your care team, or schedule a consultation to learn more.