Clinical radiopharmacy: principles and practices

Role of the clinical radiopharmacist in patient safety during myocardial perfusion imaging with vasodilator stress agents

AIM

To assess the radiopharmacist's role in a multidisciplinary team focused on the contraindications of regadenoson in order to ensure the safe use of pharmacologic vasodilator stress agents in patients undergoing SPECT-MPI.

METHODS

We ambispectively studied its safe use in 1905 patients (54.1% female, mean age: 66.6±11.7 years, range: 20-95 years). Sex, age, medical history, medications, drug allergies, and contraindications for stress testing were registered together with recommendations for the nuclear physician in charge.

RESULTS

Detected contraindications and corresponding recommendations were as follows: risk factors for QTc interval prolongation 7.5% - measurement of QTc interval previously to test and monitor ECG; prior stroke or TIA 4.2% - consider carotid stenosis assessment; salicylates/sulfonamides allergy 3.1% - use 99mTc-sestamibi; epilepsy or risk factors for seizures 2.4% - use of adenosine or reconsider test indication; systemic corticosteroid therapy for severe COPD 1.3% - reassessment of patient's condition; acute exacerbation of COPD 0.8% - defer test until acute episode is over; severe asthma 0.4% - do not perform test; methylxanthine ingestion 0.3% - avoid consumption previously; other 6.1% - evaluation of other contraindications. No contraindications were detected in 73.6% of patients. The test was canceled due to absolute contraindications in 2.9% of the requests.

CONCLUSIONS

Working in a systematic way, the radiopharmacist was able to detect a high number of issues related to regadenoson, with one out of four patients presenting some clinical contraindication. The recommendations given by the radiopharmacist were well accepted by the nuclear physicians who changed their approach contributing to increase the safety of patients referred for MPI.

Platypnea-orthodeoxia syndrome: Importance of patient position for correct diagnosis at the time of (99m)Tc-MAA injection

A 65-year-old male presented with unexplained hypoxia that became exacerbated by an upright posture (platypnea-orthodeoxia syndrome) secondary to hepatopulmonary syndrome (HPS). A (99m)Tc-macroaggregated albumin pulmonary perfusion scan revealed a right to left shunt of 29% in the sitting position, which had not been previously detected when the radiotracer injection was performed with the patient in supine position, nor was it diagnosed using another non-invasive imaging method (transthoracic contrast echocardiography and angio-CT). A transesophageal echocardiography was contraindicated due to the presence of esophageal varices. The administration of the radiopharmaceutical in sitting position for the study of the pulmonary perfusion allowed us to confirm the presence of the shunt and consider the patient a candidate for liver transplantation.

Combination therapy for non-Hodgkin's lymphoma: an opportunity for pharmaceutical care in a specialty practice

OBJECTIVE

To describe the application of pharmaceutical care practices in the administration of new therapeutic radiopharmaceuticals used in the treatment of non-Hodgkin's lymphoma (NHL).

PRACTICE DESCRIPTION

At the Antibody Labeling Facility at the University of Nebraska Medical Center, the nuclear pharmacist provides support in the formulation, preparation, and quality testing of radiopharmaceuticals. The nuclear pharmacist also provides direct patient care by assisting in the administration of radiopharmaceuticals, monitoring patients during their infusions, and counseling patients on radioimmunotherapy and radiation safety.

PRACTICE INNOVATION

Expanding the role of the nuclear pharmacist in treating patients with NHL using radiolabeled monoclonal antibodies (MABs).

INTERVENTIONS

The nuclear pharmacist provides specialized pharmaceutical care by being involved in planning patient care, administering diagnostic and therapeutic radiopharmaceuticals, performing individualized patient dose calculations, monitoring patients, and counseling patients.

MAIN OUTCOME MEASURES

Number of patients treated with radiolabeled MABs.

RESULTS

Since January 1996, 85 patients with NHL have been treated using 131I-tositumomab (Corixa, GlaxoSmithKline), an anti-B1 MAB, under various clinical research protocols requiring specialized pharmaceutical care. The nuclear pharmacist on the team provided direct patient care, assisting with the administration of diagnostic and therapeutic radiopharmaceuticals under a collaborative agreement with a nuclear medicine physician or a radiation oncologist. Other pharmaceutical care activities performed include calculating individual patient doses, obtaining medication histories, counseling patients on their therapy and on radiation safety after early release, and monitoring patients for adverse effects during medication infusion. Patients have responded favorably to nontraditional nuclear pharmacy activities.

CONCLUSION

The nuclear pharmacist has become an important member of the health care team that provides a new and unique therapy for patients with NHL. To date, the nuclear pharmacist, in collaboration with the nuclear medicine physician or the radiation oncologist, has successfully administered the tositumomab and 131I-tositumomab combination therapy without significant incident.