Calculation of the standard uptake value (SUV) and image quality in positron emission tomography (PET) hinges on accurate dose delivery. Extravasation or partial extravasation of the radiopharmaceutical dose can undermine SUV and image quality, and contribute to unnecessary imaging (time and CT dose). Topical sensor characterisation of injections has been reported, with extravasation rates ranging from 9% to 23% for 18F-FDG after manual injection. Method: A single site, single PET/CT scanner was used to characterise injections using an autoinjector with standardised apparatus, flush volume and infusion rate using 18F-FDG, 68Ga-PSMA and 68Ga-DOTATATE; more reflective of Australian PET facilities. 296 patients with topical application of LARA sensors were retrospectively analysed. Results: Only 1.1% of studies showed evidence of partial dose extravasation. In total, 9.1% were identified to have an injection anomaly (including venous retention). No statistically significant differences were noted across the radiopharmaceuticals for demographic data. Although not demonstrating a statistically significant correlation, there was more extravasated doses associated with female patients (P = .334), right side (P = .372), and hand injections (P = .539). Extravasation was independent of dose administered (P = .495), the radiopharmaceutical (P = .887), who injected the dose (P = .343), height (P = .438), weight (P = .607) or age (P = .716). Extravasation was associated with higher glucose levels (P < .001), higher t-half (P = .019) and higher aUCR10, tc50, aUCR1 and c1 (all P < .001). Conclusion: Topical monitoring and characterisation of PET dose administration is possible and practical with the LARA device. Extravasation and partial extravasation of PET doses are not only readily detected but they are also preventable. The LARA device can provide the insights into variables that could eliminate extravasation as a cause of image quality or SUV accuracy issues.