Introduction
Emergence of image guidance technology
Today’s computer-aided healthcare technology relies on much modality medical image and multimedia information. An image-guided radiation therapy was introduced due to the ever-increasing challenges originating from fast growth of the information technology sector and the global expansion of healthcare needs. Image guided technologies aid in the effective management of patients in the areas of detection, diagnosis and intervention. The image guidance technologies is a process that uses frequent imaging during a radiation therapy in order to improve accuracy and precision in delivering of treatment (Peters & Cleary 2008). Before the introduction of image guidance technology, physicians had many challenges determining the exact location of a tumor on the tumor bearing tissue (Lecchi, et al 2008). In addition, the radiation dose could not accommodate larger volumes that could not expose surrounding tissues to the radiation. The image-guided radiotherapy exposes only areas under treatment to radiations hence avoiding complications (Xing et al 2006).
On the other hand, the recent development in the image guidance technology has offered alternative strategies for improvement of tumor control probability (TCP) and normal-tissue complication probability (NTCP). Some new techniques such as intensity-modulated radiotherapy (IMRT) has been the most effective process of tumor treatment but it has some complications associated with the spread of microscopic diseases. Physicians discovered a need of reducing the magnitude of radiation intensities caused by radiotherapy equipments in order to reduce the number of complications recorded from patients. The introduction of image guidance technology serves several purposes. Firstly, it reduces treatment margins to an optimal level. Secondly, it gives physicians the required knowledge of anatomy in real time delivery of dosage. Thirdly, the process is compatible with the daily assessment of the tumor and patient’s response to therapy (Verellen et al 2007).
Implementation of image guidance technology in radiotherapy
Image-guided radiotherapy implemented first in the dose-escalation treatment of prostate cancer. The implementations led to improved control over biological chemicals and prevention of bladder and rectal complications. Secondly, image guidance technologies were used in the treatment of rectal cancer whereby helical tomo-therapy has reduced incidences of urinary toxicity and acute gastrointestinal (Price and Heap 2008; Evans 2008).
Use of image guidance in the treatment room
In the treatment room, the image-guided technique uses various imaging techniques that aid in determining the location of target areas. The process uses machines such as cyclotron or linear accelerator that are equipped with imaging technologies. A physician uses the technique in locating the target area before and during the time when radiation is delivered with the patient positioned on the table. With the aid of specialized computer software, the images are compared to images observed during simulation and any useful adjustments made to the patient’s position and the radiation beam for more precision (The radiology information for patients 2013).
The image guided radiation technology uses magnetic resonance imaging (MRI), computer tomography (CT), positron emission tomography (PET), ultra sound (US), and X-ray. In addition, newer image guided technologies have been introduced that uses non-radiation light emitting diode on the patient’s body while on the operating room. The ability of an image-guided radiotherapy to control tumor in patients is proportional to the amount of dose delivered (The radiology information for patients 2013).
People involved in the procedure
A treatment plan team used in the operation of the image-guided technologies in the treatment room composes of a radiation oncologist, therapeutic medical physicist, radiation therapist, and dosimetrist. The radiation oncologist evaluates the patient and prescribes the best therapy for his or her condition. In addition, the physician specifies the treatment area and the best dose to deliver. Moreover, the dosimetrist and the medical physicist assist the radiation oncologist in determining the best technique for delivering the prescribed dose. On the other hand, radiation therapists with the dosimetrist make precise calculations. Radiation therapists use technology in acquiring images and delivering daily treatment plans (The radiology information for patients 2013).
Equipments used
In the treatment room, the image guided radiation therapy equipment is mounted on the machine delivering radiations. A special camera located at a strategic position in the room emits LED light and is used in tracking the patient’s body surface (Lecchi 2008).
Special preparations in the treatment room
Before any activity is carried out in the operation room, the physician must know the status of the patient. Women are advised to state whether they are pregnant, or breastfeeding because such situations require special preparation. The success of an image guided radiotherapy radiation depends on the TCP and NTCP. Patients with high proportions are not administered with the biological dose used for tumor eradication because they have a high probability of complications. At the start of the image-guided radiotherapy, a patient’s body is marked with radio-dense markers where the treatment will be carried out for easier identification. Radio-dense markers are used because they prevent x-rays from entering the body. Markers appear white on the image and are placed approximately one week prior to the treatment. In addition, the patient’s body is marked with colored ink that assists in easier alignment of the radiation equipment (The radiology information for patients 2013).
Operation of the equipments
A radiation therapist operated the image guided technology machines while the radiation oncologist supervises the process. Before each session begins, the patient is positioned carefully with the marks on the screen identifying the treatment areas (Evans 2008).
The advantages and disadvantages of implementing image guidance technologies into the radiotherapy processes
Image guidance technologies have many benefits on radiotherapy processes. Firstly, image guidance technologies ensure treatment delivery. The process assists patient positioning whereby, a patient undergoes several weeks of daily treatment that ensures correct positioning that eliminates inter-fraction motion. Secondly, image guidance technologies offers three-dimensional in-room imaging that offers solutions to effective patient positioning. Thirdly, image guidance technologies in radiotherapy processes allow treatment of intra-abdominal organs that are more radiosensitive than other solid tumors. The technology allows for possible prescription of tumoricidal radiation doses without affecting other tissues around the affected location. Fourthly, image guidance technologies can be used on organs that are in motion. The image guided radiotherapy process offers peripheral solutions that can cope with organ motion or patient motion during irradiations. The process achieves this by having equipments not directly mounted on the image guided radiotherapy machine (Dawson and Sharpe 2006).
On the other hand, image guidance technologies have some disadvantages. Firstly, the image guided radiotherapy process can cause serious damage to nearby tissues if used by an inexperienced person. The area under treatment must be marked with precision and any small mistake leads to many complications. Secondly, high technology is required in operating the equipments that might not be available in most countries. In addition, the high cost of image guided radiotherapy equipments leaves some healthcare centers with no alternative but utilize other traditional methods (Dawson and Sharpe 2006).
Conclusion
Image guidance technologies have found many uses in the healthcare industry and most hospitals have acquired the equipments that use this new technology. Image guidance technology is mostly used in radiotherapy processes because it is more effective and does not have many tissue complications. Engineers should look for more advanced ways of improving this technology in order to eliminate all the disadvantages discussed above and save more lives.
List of references
Dawson, L.A. and Sharpe, M.B. (2006). ‘Image guided radiotherapy: rationale, benefits and limitations’ Lancet Oncol, Vol 7 Iss. 10; 848-58.
EVANS, P.M. (2008). ‘Anatomical imaging for radiotherapy’ Physics in Medicine and Biology 53 R151-R191.
LECCHI, et al. (2008). ‘Current concepts on imaging in radiotherapy’ Eur J Nucl Med Mol Imaging, 35:821-837.
PETERS, T. M., & CLEARY, K. R. (2008). Image-guided interventions: technology and applications. New York, Springer.
PRICE, P. AND HEAP, G. (2008). ‘Implementing image-guided radiotherapy in the UK: plans for a co-ordinated UK research and development strategy’ The British Journal of Radiology, 81, 379–382.
VERELLEN, D., RIDDER, D. M., LINTHOUT, N., TOURNEL, K., SOETE, G. AND STORME, G.. (2007). Innovations in image-guided Radiotherapy. Nature Publishing Group, pp. 949-950. Retrieved from:
http://www.medicalphysicist.co.uk/igrt_innovations.pdf
XING, L. et al. (2006). ‘Overview of image-guided radiation therapy’ Medical Dosimetry, Vol. 31, No. 2, pp. 91-112,
