One of the most discussed and debated concerns with radiation exposure is the risk of cancer associated with it. Although, there is wide disagreement about the extent of cancer risk; experts agree that there has to be a balance between benefits of imaging scans and risks posed by them. Calculating the risk to patients is a complex process that often does not generate any clear answers. Yet, radiation dose management is gaining popularity among Indian hospitals.
Dr Sharad Maheshwari Diagnostic Radiologist, Kokilaben Dhirubhai Ambani Hospital, Mumbai |
“There is reasonable, though not definitive, epidemiological evidence that organ doses in the range from 5 to 125 mSv result in a very small but statistically significant increase in cancer risk,” says Dr Sharad Maheshwari, Diagnostic Radiologist, Kokilaben Dhirubhai Ambani Hospital, Mumbai. “These results come primarily from studies of approximately 30,000 atomic-bomb survivors who were several kilometres away from the explosions and were thus exposed to low doses,” Dr Maheshwari explains. In a study, Berrington de gonzalez et al estimated that approximately 29,000 future cancer cases could be related to CT scans performed in the US in 2007 alone.
| Goals for Radiation programmes |
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In India, there is considerable buzz regarding radiation dose reduction and management, but this somehow fizzles out at the operational level. “At the operational level, there is scope for improvement in the radiation safety processes followed by many institutions,” says Raveendran Gandhi, Senior Director, Radiology, Philips India. “At the operational level, technologists and doctors who operate CT scanner machines should be well qualified and adequately trained on the radiation aspects and should be aware about radiation dose delivered to patients for every investigation conducted on the equipment. Optimum quantity of dose should be delivered for CT tests adhering to as low as reasonably achievable (ALARA) principle for obtaining diagnostic quality images,” he explains.
Raveendran Gandhi Sr. Director- Radiology, Philips India |
Apart from this, on-site monitoring and site inspection during installation of the facilities and accessories, proper equipment installation, optimised use of radiation protection devices, radiation checks by integrating with equipment vendors should be mandatory to minimise dose to operators and public from CT scanners. Presence of site radiation safety officers, training of the operators, planning and implementing QA processes and SOPs as well as conducting periodic radiation safety checks are essential requirements in the process of efficient radiation safety management. These multiple tasks will require on-going expert interactions and engagements from members of radiation facilities with regulators who will guide and be empowered to conduct regular monitoring for ensuring safety compliance.
Dr Chandrasekar COO & Chief Radiologist, Yashoda Hospital, Hyderabad |
“Ionising radiation is a double edged sword and has harmful effects such as causing infertility, radiation burns and cancer on prolonged exposure or on exposure beyond a permitted threshold,” opines Dr R Chandrasekar, COO and Chief Radiologist, Yashoda Hospital, Hyderabad. “Careful handling, dose optimisation and strict adherence to the safety guidelines are of utmost importance in ensuring that its harmful effects on patients and hospital staff are minimised,” he adds.
Radiation dose management programme at hospitals
Sanjay David Business Head – CT Scanners, Siemens Healthcare, India |
The most systematic way to track, report and monitor radiation dose and eliminate unnecessary exposure is to develop a comprehensive, radiation dose management programme. “Radiation dose management starts with a conscious choice by institute/hospital to educate, monitor and maintain optimal radiation dose. Besides acquiring the right technologies, the focus should be on education and sensitising the staff on the benefits of radiation management and radiation safety,” says Sanjay David, Business Head-CT Scanners, Siemens Healthcare, India. “CT dose management relies on the ability of institutes/hospitals/organisations to adequately educate, monitor and maintain CT radiation. This forms the core of right dose management and radiation safety,” he adds.
In India, Atomic Energy Regulatory Board (AERB) has the mandate of ensuring radiation safety. “As per AERB regulation, it is essential for hospitals offering CT scans to have documented procedures and programmes for radiation safety,” explains Gandhi. “The programme should be managed by a certified Radiation Safety Officer (RSO). Periodical safety assessment reports should be recorded and reports should be submitted to AERB. Operational licenses are required for the facility, equipment installation and continuous operations of CT scanners in hospitals. These regulations are essentially compelling in nature to implement effective radiation safety programmes,” he further adds.
Dr Priya Darshan Chudgar Consultant Radiologist, Kohinoor Hospital, Mumbai |
Talking about the guidelines followed to minimise radiation at Mumbai’s Kohinoor Hospital, Dr Priya Darshan Chudgar, Consultant Radiologist, Kohinoor Hospital says that CT exams must be appropriately ustified for clinical need. All technical aspects of each CT examination must be optimised. The most dose-efficient technique should be used to achieve the target image quality. For instance, these are the techniques followed at Kohinoor Hospital:
- Justification of the CT examination from referring physicians
- Not using unnecessary CT examinations (e.g., whole-body screening)
- Optimising the dose performance of detector, collimator and beam-shaping filter
- Using manual technique charts or automatic exposure control systems to adapt the dose to patient size, and select the appropriate tube potential
- Improving data processing and image reconstruction to gain more information from each study and avoid repeat examinations
R K Gupta Director & HOD – Dept of Radiology & Imaging, Fortis Memorial Research Institute, Gurgaon |
Expressing his views, Dr RK Gupta, Director & HOD – Department of Radiology & Imaging, Fortis Memorial Research Institute, Gurgaon, says, “It is very important to use protocols with reduced radiation to ensure optimal image quality with minimal radiation. All children below 16 years of age should not undergo diagnostic procedures which use radiation including CT unless it is absolutely justified and indicated and we do not have options like USG, IR imaging, optical and MR imaging for those investigations.”
Goals of dose management programmes
Dose management programmes involve collaborative efforts of the entire radiology department. Elaborating on the topic Dr Maheshwari says, “The radiology department has certain guidelines which have been posted on the intranet and are available for radiology staff, including radiologists, resident radiologists (assistants/ associates), DNB students and technologists. The technologist and residents radiologists have been trained and sensitised to radiation protection and urged to follow the guidelines wherever possible without compromising diagnostic quality.” He further points out five primal goals for these programmes:
Gathering radiation dose data: It is the first step in the optimisation process. Typically, dose data is collected when a cause for concern is raised for some reason or as a recurring quality control measure. A more systematic approach and a permanent solution is required for automated collection of dose data from all modalities.
Monitoring, analysing and finding best practice: A dose monitoring solution is required to implement ALARA principles. In-depth analysis, benchmarking between different modalities, different hospitals, or even different technologists and doctors leads to developing best practices.
Visualising radiation dose data (multidisciplinary team approach): Showing the dose level will create a curiosity about dose. That is an important first step in raising the discussion and finding the optimal balance between dose and diagnostic quality. The interest in dose monitoring needs to spread from the physicists to radiologists, technologists and clinicians.
With the dose information at hand, better decisions can be made, answering questions such as: Which type of follow-up examination is optimal? Given the higher dose level, is the CT exam really necessary or is a regular X-ray sufficient?
Appropriate use of radiation: It is an important patient safety and quality issue. Radiation dose-management programmes should focus on determining the right test at the right dose in a timely fashion. Ensure that the test is clinically indicated; avoid duplicate tests; and make sure alternative tests, such as an ultrasound or magnetic resonance imaging, are not viable options.
Keeping pace with technology: Another challenge is the fast pace of technological development. In many instances, the technology is not being used to its fullest extent to help reduce radiation exposure. Forming strong vendor relationships and participation in training for technologists can help overcome this challenge.
Most important for dose management programme
Most dose management programmes look at appropriate justification for ordering and performing each procedure, and careful optimisation of the radiation dose used during each procedure. Explaining the process further Dr Maheshwari lays down the following points:
Justification and optimisation
Setting a goals to use imaging only when the potential clinical benefit outweighs the potential risk and to strive for an imaging examination that delivers the lowest dose necessary to obtain the desired information: In short, we must aim for justification and optimisation of each imaging procedure
Standardisation is crucial
Professional organisations, including American College of Radiology (ACR) and the American College of Cardiology (ACC), have developed and are working to disseminate imaging referral criteria, called “appropriateness criteria” or “appropriate use criteria,” associated with a number of medical conditions. However, criteria for appropriate ordering of medical imaging exams have not yet been broadly adopted by the practising medical community.
Ensure the right test
Enhance communication between ordering physicians and radiologists to ensure that the right test is ordered based on an individual patient’s needs and diagnostic requirements.
Ensure the right dose
Conduct a periodic check of imaging equipment to ensure proper functionality. Adopt “ALARA” guidelines set forth by the US Nuclear Regulatory Commission. Develop low dose protocols. Develop a process to review dose protocols on an annual or biannual basis to ensure that protocols are followed. Examine cases in which protocols were not followed and provide education to prevent future occurrence.
Increase patient awareness
Empower patients with information and tools to help them and their physicians manage their exposure to radiation from medical imaging in the short term, even before longer-term changes take effect.
Developing comprehensive radiation dose-management programmes to track, report and monitor patients’ exposure. Patients can be provided with a medical imaging record card that tracks the type of test performed, the date and location of the test and the radiation dose
Technology of dose management
There are numerous tools for dose management. In fact, various vendors have inbuilt software and mechanisms to manage and reduce radiation dosage like:
- X-ray beam filtration
- X-ray beam collimation
- X-ray tube current modulation and adaptation
- Patient body habitus (automatic exposure control)
- Peak kilovoltage optimisation
- Improved detection system efficiency
- Noise reduction algorithms
- Iterative reconstruction
Sharing responsibility
Most equipment manufacturers today are torchbearers of dose management and have focused services for dose reduction and management for the doctors. “CT dose management relies on the availability of dose data and adequately educated personnel. These two aspects are at the core of right dose management, which further optimises dose reduction,” says David.
“We have applied the ALARA principle to its true spirit while designing our low dose diagnostic machines. We strive to excel in this field by extensive research and regularly come up with latest technologies in reducing radiation dose in our new and existing diagnostic devices,” says Gandhi.
Some of the initiatives by leading equipment manufacturers are:
Siemens Healthcare
DoseMAP – Siemens CT Dose Management Programme: Provides functionalities like CARE Analytics to report, document and analyse dose. It lets the user access dose values per case, per examination type or per patient. Additionally, access to scan protocols can be restricted to protect the set dose levels and to prevent unauthorised changes to the scan parameters.
EduCARE: It bundles dedicated trainings from Siemens that focus on key technologies and their application in clinical practice. Exclusive tutorials, webinars, e-trainings and brochures cover a wide range of topics related to achieving the right dose.
Optimize CARE CT: It is a cross-modality consultancy programme offered by Siemens Customer Service. Over the course of the programme, Siemens professionals guide users towards optimising the use of radiation in order to reduce dose. Through onsite and offsite support and trainings, users learn how to use the right dose technology to deliver the right dose levels for every patient.
Philips Healthcare
iDose4 is an iterative based reconstruction technology recently introduced with Philips CT scanners through which the machine is enabled to reduce radiation dose up to 80 per cent without compromising on the quality of images it delivered. iDose4 is also capable of improving the image quality at low radiation dose! The company claims to has shipped more than a thousand iDose4 Scanner upgrades within a short span of its inception into the market. This technology is among the most successful low dose imaging technology in the CT industry which got widely appreciated by the entire radiology community. Philips CT received excellence in radiology award from AuntMinnie.com (the “Minnies” awards recognise excellence in radiology) which picked out the iDose4 Premium Package as the Best New Radiology Software during RSNA 2012.
“Dose-Aware” is a radiation exposure monitoring device which Philips developed for cath lab operators. This device will provide live feed about total exposure the operator received during a cath lab procedure to avoid unnecessary exposure to radiation.
GE Healthcare
GE Blueprint: Launched in June 2012, GE Blueprint offers a comprehensive approach based on an assessment of a healthcare provider’s technology, people and processes and helps identify breakthrough imaging technologies, system-specific solutions and processes, and comprehensive imaging “blueprints” to help providers achieve low-dose, high-definition diagnostic capabilities. GE Blueprint’s goal is to work with healthcare providers to reduce their average patient exposure by up to 50 per cent, based on longitudinal tracking of average dose.
DoseWatch, enables radiologists to measure, track and optimise patient radiation dose over time. It is a web-based dose monitoring software used to capture, track and report radiation dose statistics directly from the imaging device, multi-modality and vendor agnostic. Doctors can produce sharp, focused diagnostic images, all while keeping dose levels as low as reasonably achievable (ALARA). DoseWatch monitors cumulative dose over time, and prevents excessive medical radiation exposure.
More to come
The healthcare industry in India is undergoing rapid changes. Radiology is also evolving. It has many important clinical uses and can provide significant benefits. But the concerns related to CT, fluoroscopy, and nuclear medicine imaging procedures are also real.
In future, better software systems are expected that will help radiologists analyse images much better and avoid unnecessary radiation exposure to patients.
“The future will bring newer machines with advanced automatic exposure control techniques that select the appropriate tube potential and then modulate the tube current to reduce radiation dose. With ever-increasing computational power, iterative reconstruction will be implemented in daily clinical practice, which may lead to substantial image quality improvements and radiation dose reduction,” Dr Chudgar predicts.