In vivo validation of Dosemap software use in interventional cardiology with dosimetrics indicators and peak skin dose evaluation.

OBJECTIVES: The aim of this study was to determine the accuracy of DoseMap™ software as compared to gafchromic film in real clinical practices. BACKGROUND: The radiation exposure from cardiovascular procedures could expose patients to potential risk of cancer and/or skin injury. New tools like Dosemap software were developed to estimate the patient skin dose in the cardiac catheterization laboratory. However, little data are available to validate this estimation of patient radiation skin dose. METHODS: This is a prospective cross-sectional study comparing the peak skin dose (PSD) measured by gafchromic film used as reference with an estimated PSD given by Dosemap software, in patients with BMI > 30 kg/m2 undergoing elective diagnostic and/or therapeutic interventional cardiology procedures, from April 2016 to December 2016, at the Brest University Hospital Centre, France. RESULTS: After four exclusions of patients for poor quality of gafchromic films, 90 patients were included, with 58 angiography (67.4%), 14 percutaneous interventions (16.3%), and 14 both (16.3%). The median PSDDosemap and PSDFilm were similar with 157 mGy [IQR: 99; 273] versus 158 mGy [IQR: 101; 295] (P = 0.65), respectively, with an excellent correlation (r = 0.95). The comparison between cumulative air kerma and PSDFilm was different 366 mGy [IQR: 246; 575] versus 158 mGy [IQR: 101; 295] (P < 0.01) with moderate correlation (r = 0.79). No correlation was found between the dose area product and PSDFilm (r = 0.51). CONCLUSION: DoseMap is an effective and valid method as compared to gafchromic films to estimate PSDs during interventional cardiologic procedures.

Impact of experience and technical changes on acute urinary and rectal morbidity in low-dose prostate brachytherapy using loose seeds real-time implantation.

PURPOSE: To assess the impact of experience and technical changes on morbidity during the first year after permanent prostate brachytherapy. METHODS AND MATERIALS: From July 2003 to May 2010, 150 patients with prostate cancer underwent low-dose iodine-125 prostate brachytherapy as a monotherapy by the same medical team (one urologist and one radiation oncologist). Patients were divided into three periods: P1 (n = 64), P2 (n = 45), and P3 (n = 41) according to technical changes: use of an automatic stepper from P2, use of a high-frequency ultrasound probe in P3. Urinary toxicity was analyzed according to the incidence of acute urinary retention (AUR), Delta International Prostate Symptom Score (Δ IPSS) defined as IPPS maximal - IPSS at baseline, and proportion of patients with Δ IPSS ≥5 and IPSS total >15. The Radiation Therapy Oncology Group classification was used to evaluate the rectal morbidity. RESULTS: The incidence of AUR (6% overall) decreased significantly with time: 12.5% (8/64) during P1, 2.2% (1/45) in P2, and 0% in P3 (p = 0.014). Mean Δ IPSS (11.6) remained stable during the three periods. Patients with Δ IPSS ≥5 and IPSS total >15 were 58.7%, 58.1%, and 56.1% for P1, P2, and P3 (p = 0.96), respectively. Grade 1 and 2 proctitis were observed in 15.3% and 9.3% of the patients without any significant difference between the three periods. CONCLUSION: The incidence of AUR decreased significantly with time. This was probably because of the experience of the practitioner and the use of an automatic stepper that allowed reducing prostatic traumatism. Experience and technical changes did not seem to affect rectal morbidity.