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.

Safety of regadenoson in patients with severe chronic obstructive pulmonary disease.

OBJECTIVE: To assess the safety of regadenoson, a selective agonist of A2A adenosine receptors, combined with low-level exercise in subjects with severe chronic obstructive pulmonary disease (COPD), referred for myocardial perfusion imaging (MPI). METHODS: We studied prospectively 12 male patients with severe COPD. Stress was 4min of low-level exercise with bolus injection of regadenoson (0.4mg) at 1.5min, followed by (99m)Tc-MPI agent injection. Demographics, medical history, lung medications, adverse events, oxygen saturation (SatO2), MPI findings for coronary artery disease (CAD), and changes in systolic blood pressure (SBP), and heart rate (HR) were registered. RESULTS: The observed adverse event profile of regadenoson was similar to that of patients with mild-moderate COPD. There was no clinical exacerbation of COPD. Adverse events were self-limiting: dyspnea (33.3%), fatigue (25.0%), chest pain, headache (16.7%, respectively), and gastrointestinal discomfort, dry mouth, flushing, feeling hot and dizziness (8.3%, respectively). 25.0% of patients did not report any symptoms. We observed significant increases in SBP and HR from baseline (142.6mmHg±22.3 vs 152.5mmHg±18.5, and 80 b.p.m.±18 vs 105 b.p.m.±22, respectively; p<0.05). CONCLUSIONS: Regadenoson combined with low-level exercise is safe and well tolerated in stable patients with severe COPD undergoing MPI.

[Quantitative salivary gland scintigraphy in head and neck cancer patients following radiotherapy]. / Gammagrafía salival cuantitativa en pacientes con cáncer de cabeza y cuello tratados con radioterapia.

OBJECTIVE: To assess the role of quantitative salivary gland scintigraphy (SGS) in the detection of functional impairment of salivary glands in patients with head and neck cancer treated with radiotherapy (RT). MATERIAL AND METHODS: We studied 19 patients (17 men), mean age 62.4 years (44-75). Three studies were performed to each patient: baseline, 3 and 18 months after RT. SGS was acquired for 25 minutes following injection of 3.7 MBq/kg of (99m)Tc-pertechnetate with lemon juice at the end of minute 15. Excretion fraction (EF), counts per minute/pixel/MBq (CMPM) and uptake percentage were obtained from time-activity curves from ROIs placed over parotid (PG) and submandibular glands (SMG) and related to the doses received by the PG. RESULTS: EF showed a significant reduction from the baseline to the 3 months study (p<0.001) for the PG and SMG and from the baseline to the 18 months study for the SMG (p<0.001). A significant improvement of EF was seen from the 3 months to the 18 months study for the PG (p<0.05). CMPM did not change significantly from the baseline to the 3 months and 18 months studies for the PG and showed a significant reduction (p<0.01) for the SMG from the baseline to 18 months study. The uptake percentage did not change significantly between studies. A moderate association was observed between the doses to PG and the 3m study parameters. CONCLUSIONS: EF was more sensitive than uptake in assessing post-RT impairment of salivary function. In addition, it reflected functional recovery of parotid glands over time.