A medical dosimetrist is an important member of a radiation oncology team. They work closely with the radiation oncologist to design a treatment plan that provides the most effective radiation dose distribution in the safest possible way. For mesothelioma patients, the work that the dosimetrist does is critical to achieving the best outcome with the lowest level of adverse effects.
What Does a Medical Dosimetrist Do?
The challenge of a mesothelioma diagnosis is best met with a multidisciplinary approach that includes the use of radiation therapy. Though the patient may only meet with the radiation oncologist to discuss their treatment, putting the plan into place requires a careful evaluation of the tumor type, stage, and location. Medical dosimetrists are specially trained to calculate doses of radiation and to design and oversee treatment plans.[1]
While the radiation oncologist decides on the treatment modality and dosage, the dosimetrist uses their knowledge, along with advanced computer technology, to perform calculations for accurate delivery of the dose that they have prescribed. They verify the mathematical accuracy of all calculations, document the information in the patient’s records, and perform rigorous quality assurance checks to make sure that the treatment plan is safe and effective.
The medical dosimetrist communicates the treatment plan to the radiation therapists who administer it, as well as any beam modification devices or field arrangements that may be needed. The dosimetrist may also work directly with a medical physicist.
Dosimetrists typically specialize in different types of radiation, including:
- External Beam Radiation Therapy, which delivers radiation from outside the body
- Photon therapy, which uses a linear accelerator to produce high-energy therapeutic X-rays to treat tumors
- Proton therapy that uses high-energy proton beams to treat tumors
- Brachytherapy, in which a radioactive source is placed inside or next to the area where the tumor is located.
Dosimetrist skills include:
- Knowledgeable in anatomy, physiology, clinical oncology, radiobiology, radiation physics, and radiation safety.
- Expertise in radiation oncology and medical physics technology and their use in treatment plans that include multi-modality imaging.
- Knowledgeable in healthcare informatics.
The Dosimetrist’s Role in Treating Mesothelioma
Radiation therapy is frequently used to treat malignant mesothelioma. Though the protocol is rarely successful on its own, it can be used after surgery to try to kill small areas of the cancer that were not removed during the surgery. Radiation can also be used as a palliative procedure to ease patients’ symptoms and improve their quality of life. Both external beam radiation therapy and brachytherapy have proven effective for these uses.
Dosimetrists are integral to the success of brachytherapy. They ensure that the radiation dose delivered to the tumor is accurate and in line with the prescribed treatment plan. They calculate and measure the radiation dose distribution to ensure it conforms to the physician’s goals. They use advanced techniques and tools to assess the radiation levels at specific points within the patient’s body to ensure that the treatment is effective and safe.[2]
Similarly, when external beam radiation therapy is used to treat malignant mesothelioma, a medical physicist and dosimetrist will work together to calculate the correct radiation dose and design custom energy beams to fit the patient’s condition and the radiation oncologist’s orders. They will then program the radiation therapy equipment to properly deliver the radiation without causing harm to healthy tissue or to the internal organs.[3]
The Benefits of Dosimetry Expertise in Treating Mesothelioma
The work that dosimetrists do ensures that dose volumes ordered by radiation oncologists are delivered properly and optimal for patient safety and effectiveness. Studies regarding dosimetry have made significant contributions to the success of treatment for malignant mesothelioma.
One such study was conducted in 2020 when researchers set out to determine the radiation therapy dosages that correlated with severe radiation pneumonitis in patients with malignant pleural mesothelioma. Studying data from 40 patients who had undergone pleurectomy decortication and adjuvant radiation therapy, the researchers recorded and studied dosimetric variables and determined the correct dosage of radiation to reduce the incidence of this serious adverse effect of the treatment.[4] With this information has been incorporated in dosimetrists’ calculations since the study was conducted.
Though mesothelioma patients are unlikely to meet the dosimetrist who is working on their care, they can be confident that they are doing their best to determine the most desirable results for them and working diligently to achieve them.
Cleveland Clinic. (N.D.). External Beam Radiation Therapy.
NIH National Library of Medicine. (May 1, 2020.). Dosimetric Correlates of Pulmonary Toxicity in Patients with Malignant Pleural Mesothelioma Receiving Radiation Therapy to the Intact Lungs.