CONTRAST MEDIA AND RADIATION DOSE OPTIMISATION IN GERIATRIC PATIENTS ON POLYPHARMACY UNDERGOING DIAGNOSTIC IMAGING: A CROSS SECTIONAL STUDY FROM THE KONKAN REGION

Abstract

Background: Older adults in coastal Maharashtra's Konkan region frequently present for contrast-enhanced and radiation-based imaging while managing multiple chronic conditions and medication regimens. Age-related decline in renal function, altered body composition, and polypharmacy-associated drug interactions may increase the risk of contrast-associated kidney injury, haemodynamic effects of imaging premedication, and cumulative radiation exposure, yet contrast and CT dosing protocols are largely extrapolated from data in younger adults. Objective: To evaluate the prevalence of polypharmacy among geriatric patients referred for contrast-enhanced and radiation-based imaging, and to propose an age- and renal-function-adjusted framework for contrast media use and radiation dose optimisation in this population. Methods: A cross-sectional observational study was conducted in tertiary care centres in the Konkan region over an 18-month period. A total of 104 patients aged 65 years and above undergoing contrast-enhanced CT, contrast enhanced MRI, CT angiography, or fluoroscopic and interventional procedures were enrolled. Medication history, comorbidities, renal function (estimated glomerular filtration rate, eGFR), contrast agent and volume, and radiation dose indices were recorded. Patients were stratified by age band (65–74, 75–84, ≥85 years) and by number of concurrent medications. Results: Polypharmacy (≥5 concurrent medications) was present in 84 of 104 patients (80.8%), rising from 64.6% in the youngest band to 100% in patients aged 85 years and above. Mean eGFR declined progressively with age (68.4, 54.2, and 41.7 mL/min/1.73 m² respectively). Protocol modification from the standard adult protocol was required in 47 patients (45.2%) overall, most frequently for iodinated contrast-enhanced CT in patients on metformin, ACE inhibitors, NSAIDs, or diuretics, and for iodinated contrast exposure in patients on amiodarone. Imaging-related adverse events were more common in the oldest and most polymedicated group (29.4% versus 6.3% in the youngest band). Conclusion: Polypharmacy and declining renal function are common among geriatric patients referred for contrast enhanced and radiation-based imaging in this region, and both materially influence appropriate contrast media selection, contrast volume, and radiation dose. A structured, renal-function- and interaction-aware protocol adjustment framework is proposed and may reduce adverse events without compromising diagnostic image quality.