Benefits and limitations for the use of radiation dose management systems in medical imaging. Practical experience in a university hospital.

OBJECTIVES: Radiation dose management systems (DMS) are currently used to help improve radiation protection in medical imaging and interventions. This study presents our experience using a homemade DMS called DOLQA (Dose On-Line for Quality Assurance). METHODS: Our DMS is connected to 14 X-ray systems in a university hospital linked to the central data repository of a large network of 16 public hospitals in the Autonomous Community of Madrid, with 6.7 million inhabitants. The system allows us to manage individual patient dose data and groups of procedures with the same clinical indications, and compare them with diagnostic reference levels (DRLs). The system can also help to prioritise optimisation actions. RESULTS: This study includes results of imaging examinations from 2020, with 37,601 procedures and 286,471 radiation events included in the radiation dose structured reports (RDSR), for computed tomography (CT), interventional procedures, positron emission tomography-CT (PET-CT) and mammography. CONCLUSIONS: The benefits of the system include: automatic registration and management of patient doses, creation of dose reports for patients, information on recurrent examinations, high dose alerts, and help to define optimisation actions.The system requires the support of medical physicists and implication of radiologists and radiographers. DMSs must undergo periodic quality controls and audit reports must be drawn up and submitted to the hospital's quality committee.The drawbacks of DMSs include the need for continuous external support (medical physics experts, radiologists, radiographers, technical services of imaging equipment and hospital informatics services) and the need to include data on clinical indication for the imaging procedures. ADVANCES IN KNOWLEDGE: DMS perform automatic management of radiation doses, produces patient dose reports, and registers high dose alerts to suggest optimisation actions. Benefits and limitations are derived from the practical experience in a large university hospital.

High filtration in interventional practices reduces patient radiation doses but not always scatter radiation doses.

OBJECTIVES: In fluoroscopy-guided interventional practices, new dose reduction systems have proved to be efficient in the reduction of patient doses. However, it is not clear whether this reduction in patient dose is proportionally transferred to operators' doses. This work investigates the secondary radiation fields produced by two kinds of interventional cardiology units from the same manufacturer with and without dose reduction systems.Methods:Data collected from a large sample of clinical procedures over a 2-year period (more than 5000 procedures and 340,000 radiation events) and the DICOM radiation dose structured reports were analysed. RESULTS: The average cumulative Hp(10) per procedure measured at the C-arm was similar for the standard and the dose reduction systems (452 vs 476 µSv respectively). The events analysis showed that the ratio Hp(10)/KAP at the C-arm was (mean ± SD) 5 ± 2, 10 ± 4, 14 ± 4 and 14 ± 6 µSv·Gy-1·cm-2 for the beams with no added filtration, 0.1, 0.4 and 0.9 mm Cu respectively and suggested that the main cause for the increment of the ratio Hp(10)/KAP vs the "standard system" is the use of higher beam filtration in the "dose reduction" system. CONCLUSION: Dose reduction systems are beneficial to reduce KAP in patients and their use should be encouraged, but they may not be equally effective to reduce occupational doses. Interventionalists should not overlook their own personal protection when using new technologies with dose reduction systems. ADVANCES IN KNOWLEDGE: Dose reduction technology in interventional systems may increase scatter dose for operators. Personal protection should not be overlooked with dose reduction systems.

Percutaneous structural cardiology: are anaesthesiologists properly protected from ionising radiation?

During transcatheter aortic valve implantations (TAVI) and other percutaneous structural procedures, some patients may need close anesthesiological care, thus exposing the anaesthesiologist to x-rays. This work aims to investigate the radiation dose received by anaesthesiologists during these specific procedures in order to improve their radiological protection. Occupational radiation doses were measured prospectively during percutaneous structural procedures in several health professionals using electronic dosimeters worn over the apron at chest level. A sample of 49 procedures were recorded, where the anaesthesiologists' average dose per procedure resulted 13 times higher than that of interventional cardiologists. The average dose per procedure received over the protection apron during TAVIs by the anaesthesiologist was 0.13 mSv, with a maximum value of 0.69 mSv. Taking these figures as a conservative estimation of the eye lens dose, an anaesthesiologist could participate in around 150 procedures before reaching the regulatory annual dose limit for the lens of the eye in Europe (20 mSv). In those clinical procedures where patients need close anesthesiological care, the anaesthesiologists might receive high radiation doses increasing the risk for cataracts and the risk of stochastic radiation effects. The proper use of occupational dosimeters will help identify these situations. It is recommended to use a mobile shielding barrier to reduce radiation exposure to acceptable levels in these situations.

National Diagnostic Reference Levels for Endovascular Aneurysm Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection (ICRP) has highlighted the large number of medical specialties using fluoroscopy outside imaging departments without programmes of radiation protection (RP) for patients and staff. Vascular surgery is one of these specialties and endovascular aneurysm repair (EVAR) is one of the most challenging procedures requiring RP guidance and optimisation actions. The recent European Directive on Basic Safety Standards requires the use and regular update of diagnostic reference levels (DRL) for interventional procedures. The objective of the study was to know the doses of patients undergoing EVAR with mobile Xray systems and with hybrid rooms (fixed Xray systems), to obtain national DRLs and suggest optimisation actions. METHODS: The Spanish Chapter of Endovascular Surgery launched a national survey that involved hospitals for 10 autonomous communities representing the 77% of the Spanish population (46.7 million inhabitants). Patient dose values from mobile Xray systems were available from nine hospitals (sample of 165 EVAR procedures) and data from hybrid rooms, from seven hospitals, with dosimetric data from 123 procedures. The initial national DRLs have been obtained, as the third quartile of the median values from the different centres involved in the survey. RESULTS: The proposed national DRLs are 278 Gy cm2 for hybrid rooms and 87 Gy cm2 for mobile Xray systems, and for cumulative air kerma (cumulative AK) at the patient entrance reference point, 1403 mGy for hybrid rooms, and 292 mGy for mobile systems. CONCLUSION: An audit of patient doses for EVAR procedures to identify optimised imaging protocol strategies is needed. It is also appropriate to evaluate the diagnostic information required for EVAR procedures. The increase by a factor of 3.2 (for kerma area product) and 4.8 (for cumulative AK) in the DRLs needs to be justified when the procedures are performed in the hybrid rooms rather than with mobile Xray systems.

Strategies to optimise occupational radiation protection in interventional cardiology using simultaneous registration of patient and staff doses.

The International Commission on Radiological Protection recommends that occupational protection and patient protection be managed in an integrated approach. This paper describes the experience and the initial results of a system able to register and to process simultaneously staff and patient doses in interventional cardiology and the practical use of this system in the optimisation of occupational exposure. The system used simultaneously collects and manages patient and staff doses for all radiation events. The personal electronic dosimeters worn over the protective apron of health professionals working inside catheterisation laboratories can send (wireless) doses and dose rate values to an X-hub and provide the operators inside the catheterisation rooms with real-time information. Individual and global reports for all the health professionals may be periodically obtained from the system to help with the optimisation. The results for eight cardiologists, one fellow and four nurses for a total of 2468 interventional cardiology procedures and 3207 occupational dose values collected over one year are presented here. Annual doses Hp(10) measured over the apron for cardiologists ranged from 0.3 to 6.3 mSv. For the cardiologist, the ratio between occupational doses (over the apron) and patient doses ranged from 0.05 to 0.23 µSv Gy-1 cm-2, with a mean value of 0.12 µSv Gy-1 cm-2. The system allows defining optimisation strategies by comparing the results between the different operators while considering the workload and complexity of the procedures (based on the total Kerma Area Product managed by the different operators). The registration of the date and time of the occupational radiation doses allows auditing the use of the personal dosimeters worn by the various operators.

Realistic approach to estimate lens doses and cataract radiation risk in cardiology when personal dosimeters have not been regularly used.

Interventional fluoroscopic guided cardiac procedures lead to radiation exposure to the lenses of the eyes of cardiologists, which over time may be associated with an increased risk of cataracts. This study derives radiation doses to the lens of the eye in cardiac catheterization laboratories from measurements of individual procedures to allow for estimates of such doses for those cases when personal dosimeters have not been used regularly. Using active electronic dosimeters at the C-arm (at 95 cm from the isocenter), scatter radiation doses have been measured for cardiac procedures and estimated radiation doses to the lenses of the cardiologists for different groups of procedures (diagnostic, PTCAs, and valvular). Correlation factors with kerma area product included in the patient dose reports have been derived. The mean, median, and third quartile scatter dose values per procedure at the C-arm for 1,969 procedures were 0.99, 0.78 and 1.25 mSv, respectively; for coronary angiography, 0.51, 0.45, and 0.61 mSv, respectively; for PTCAs, 1.29, 1.07, and 1.56 mSv; and for valvular procedures, 1.64, 1.45, and 2.66 mSv, respectively. For all the procedures, the ratio between the scatter dose at the C-arm and the kerma area product resulted in between 10.3-11.3 µSv Gy cm. The experimental results of this study allow for realistic estimations of the dose to the lenses of the eyes from the workload of the cardiologists and from the level of use of radiation protection tools when personal dosimeters have not been regularly used.

Factor tubo peritoneal. Reversión de la oclusión tubaria / Tubo-peritoneal factor. Tabal occlusion reversion

Se analizan las técnicas de oclusión tubaria bilateral más empleadas y cuáles son las que tienen mayor potencialidad de reversión. Revisando 200 casos de pacientes con factor tuboperitoneal de esterilidad se encontró que 24 solicitaban recanalización tubaria por tener antecedente de salpingoclasia. En el perfil de estas pacientes, se obtuvo un promedio de 29.4 años, con un periodo de latencia entre la oclusión tubaria y la solicitud de reversión de 4.1 años teniendo un promedio de 2 hijos vivos. Los motivos de solicitud fueron las segundas nupcias 54%, hijos fallecidos 12.5%, OTB involuntaria 12.5% alteraciones psicológicas 12.5% e inestabilidad matrimonial 8.5%. La técnica OTB más empleada fué Pomeroy 70.8%. De las 24 pacientes estudiadas, cuatro se descartaron por no reunir los requisitos necesarios, de las 20 restantes dos desertaron en el periodo preoperatorio y dos están pendientes de efectuar la renalización. De las 16 operadas, tres desertaron y siete se embarazoron; lo que dá un cuadro de 53.8% de embarazos. Resultado que está dentro de los límites de éxito reportados por otros investigadores.

Factor tuboperitoneal. Clasificación y pronóstico de las adherencias por laparoscopia / Tubo-peritoneal factor. Classification and prognosis of adhesions by laparoscopy

Se revisaron 200 pacientes estériles con factor tuboperitoneal alterado. La enfermedad adhesiva anexial fue el factor más importante en la esterilidad. La mayor parte de los casos estaban en la tercera década de vida; 40.5% fue de enfermedad inflamatoria pélvica inespecífica que respondió bien al tratamiento con antibióticos y antiinflamatorios. A mayor grado e enfermedad anexial adhesiva, menor posibilidad de embarazo

Correlación de la histerosalpingografía, pruebas de Rubin y celiotomía con los diagnósticos laparoscópicos en la permeabilidad tubárica / Correlation of hysterosalpingography, Rubins test and celiotomy with laparoscopic diagnosis in tubal permeability

No se cuenta con un método único para el estudio integral de la trompa de falopio. Los métodos más utilizados: HSG, PR y cromotubación por Laparoscopia por ser ascendentes no son fisiológicos y no evalúan la función del endosalpinx. La PR debe seguirse utilizando por evaluar la contractibilidad del miosalpinx u ostium tubario; es barato, prácticamente inócuo y coincide más frecuentemente con la laparoscopia que con la HSG. La coincidencia de permeabilidad y obstrucción tubaria por HSG y Laparoscopia se obtuvo en 70.5% y en 29.5% no hubo correlación. Las obstrucciones tubarias evidenciadas por HSG pueden ser permables a la laparoscopia por quitarse el componente espasmo-dolor en esta última prueba. Las funciones de permeabilidad en la HSG que muestran oclusión en la laparoscopia pueden deberse a defecto de técnica, hidrocromotubación preferencial, proceso inflamatório evolutivo reactivo o inducido por el estudio radiográfico. Durante la HSG no sólo se debe analizar las imáges de permeabilidad y de oclusión tubaria, sino que es obligado analizar la distribución del material radiopaco en el Douglas y tratar de evidenciar la calidad de la relación fibrio-ovárica. La laparoscopia tiene mayor grado de confiabilidad y sólo 6.7% de error. Es un estudio parorámico y evaluativo de las condiciones del aparato genital interno, pero no evidencia la contractilidad ni la imagen de las cavidades uterotubaria. Los tres métodos deben utilizarse en el protocolo de estudio de la pareja estéril y complementarse entre sí, por la falta de correlación observada y para tener un diagnóstico integral de la patología existente

Salpingostomía y resección de adherencias tubarias por microcirugía / Salpingostomy and adhesions resection by microsorgery

Se estudiaron 32 pacientes sometidas a microcirugía tubaria (salpingoovariolisis y salpingostomía) en el lapso comprendido entre Enero de 1983 y Octubre de 1984, obteniéndose el 46.87% de embarazos. En las pacientes sometidas a salpingoovariolisis se obtuvo 54.16% de embarazos. En las pacientes sometidas a salpingostomía se obtuvo 25% embarazos. No se encontraron embarazos ectópicos ni abortos hasta la fecha del estudio. Todos los embarazos ocurrieron en un periodo menor de 18 meses. A la fecha del estudio de las 15 pacientes embarazadas, 73.3% de pacientes se encontraban gestantes y en 26.6% el embarazo había llegado a término y resultó en forma satisfatoria