In the era of IGRT and small‐ and focal‐field external beam radiotherapy, brachytherapy is a dying modalityстатья из журнала
Аннотация: The use of brachytherapy has steadily declined over the past decade, at least in the United States. Much of this is possibly due to significant technological advances in external-beam radiotherapy, whereby higher doses can be delivered with smaller margins, significantly mimicking highly conformal brachytherapy. Some are even claiming that in this era of Image Guided Radiation Therapy (IGRT) and small- and focal-field external beam radiotherapy, brachytherapy is a dying modality. This is the premise debated in this month's Point/Counterpoint. Arguing for the Proposition is E. Ishmael Parsai, Ph.D. Dr. Parsai obtained his Medical Physics M.Sc. from the University of Missouri, Columbia in 1985, and his Radiation Oncology Physics Ph.D. from the Medical College of Ohio in 1995. He is currently Chief Medical Physicist in the Radiation Oncology Department at the University of Toledo Health Sciences Campus, where he is the director of the graduate medical physics program. He is also Adjunct Professor in the Department of Physics and Astronomy in the University of Toledo, Toledo, Ohio, Adjunct Professor of Nuclear Medicine in the University of Findlay, Ohio, and Adjunct Professor at Wenzhou University, P.R. of China. Dr. Parsai is certified by the American Board of Medical Physics and the American Board of Radiology (ABR) in Radiation Oncology Physics and Therapeutic Radiologic Physics, respectively. He has authored or co-authored five patents and has published about 60 articles in peer-reviewed journals and six book chapters. Dr. Parsai has served as the major advisor to 16 Ph.D. students and 54 M.S.-level students in the past 10 years. He has also served as the Editor of Medical Physics World, Chairman of the ACRO Physics Commission, on the AAPM Board of Directors and many other AAPM committees, and as an oral examiner for the ABR. Arguing against the Proposition is Zoubir Ouhib, M.S. Mr. Ouhib is the chief medical physicist at the Lynn Cancer Institute of Boca Raton Regional Hospital and Assistant Professor at the Florida Atlantic University in the Department of Medical Physics. He earned an M.S. from Georgia Tech in Nuclear Engineering and an M.S. in Medical Physics from the University of Cincinnati. He is board certified by the American Board of Radiology in Therapeutic Radiologic Physics and is a Fellow of the American College of Radiology (ACR). He has served as Chair of the American Brachytherapy Society (ABS) Physics Committee, Vice-Chair of the AAPM Brachytherapy Sub-Committee, and as a member of several AAPM Task Groups. Mr. Ouhib has published several peer-reviewed papers, and book chapters, and has presented at national and international meetings on topics such as patient safety, quality assurance, brachytherapy procedures, regulations, and medical events. He is the founder of the ABS Quality Assurance School, and is a member of the ASTRO Accreditation Program (APEX) and the ACR Physics Committee. He served as President of the AAPM Florida Chapter. With technological advances in small field Stereotactic Body Radiation Therapy (SBRT) with IGRT planning and delivery, similar dosimetric outcomes are achievable without the need for invasive surgery and its attendant complications or side effects; or the added uncertainty inherent in brachytherapy (BT) applications. This is well established for early stage prostate cancer.1, 2 Today, despite the central role it continues to play in the management of several cancer types,3, 4 there seems to be a trend in the US whereby the use of brachytherapy is in rapid decline.1, 2, 5, 6 To illustrate this point, a recent article by Petereit, et al.4 which examined changes in the management of prostate and uterine cervical cancers, found a significant decline of brachytherapy use and suggested some attributing reasons. For cervical/uterine cancer treatments, in the last decade, when brachytherapy was mostly used as a boost, image-guided SBRT has replaced it simply because it achieved similar outcomes without the risks, and the fact that many patients do not select brachytherapy. Using the Surveillance, Epidemiology, and End Results (SEER) database to study 7359 patients who received EBRT for cervical cancer between 1988–2009, Han et al.5 showed that there had been a 25% reduction in brachytherapy use. Gill et al.,6 analyzing 7654 patients with cervical cancer using the National Cancer Data Base (NCDB) treated during the period of 2004–2011, reported a decrease in the use of brachytherapy from 96.7% to 86.1%, while IMRT and SBRT treatments showed an increase from 3.3% to 13.9%. Eifel, et al.,7 in their report of patterns of radiation therapy practice, reviewed the records of 261 randomly selected patients from 45 institutions who received radiation for cervical cancer from 2005–2007 and compared them to patients treated in the period from 1996–1999. They found that 13% of patients treated from 2005–2007 did not receive brachytherapy, almost double the rate that was observed in the earlier cohort. For prostate cancer, LDR brachytherapy is only an effective or feasible monotherapy treatment modality in patients who would be just as effectively treated with external beam IMRT.8 In a mega study presented by Martin et al.1 using the NCDB to look at approximately 1.5 million patients who were treated between 1998 and 2010, found that brachytherapy use reached a peak of 17% in 2002 and steadily declined to a low of 8% in 2010. The most dramatic decline in brachytherapy procedures between 2004 and 2010 was seen at academic centers (48%), although it was also significant at comprehensive community (41%) and community cancer centers (30%).1 Similarly, Mahmood et al.2 used the SEER database to study approximately 182,000 patients treated with radiation between 2004 and 2009. They found that prostate brachytherapy procedures decreased from 44.2% in 2004 to 38.0% in 2009. Concurrently, the difference in use of EBRT instead of brachytherapy grew from 11.6% in 2004 to 24.0% in 2009. Declining rates of brachytherapy use are not just because of physicians' reluctance to put patients through these invasive procedures, but from patients' strong desire to avoid these procedures because of invasiveness, discomfort, and operative risks. In many cases, these patients can even be managed with active surveillance rather than treatment.6 The addition of IGRT and small- and focal-field external beam radiotherapy over the past decade was a valuable step in the development of modern radiation therapy. In the same period, there has been a decrease in the use of brachytherapy in the last few years. These two facts are not directly inter-related. The reasons for such a change in the use of brachytherapy are associated with reimbursement and the risk of Medical Events, which have led to a decrease of interest and training in brachytherapy over the past few years. This is not to be interpreted that brachytherapy is a dying modality but simply going through a "pause mode." Brachytherapy is an immortal art that will never die. There is a renewal of interest in training (such as the ASTRO annual meeting Prostate Brachytherapy Simulation Workshop). In the US, the risk of clinical insignificant Medical Events in brachytherapy relative to EBRT is being mitigated by more reasonable rules proposed by the USNRC. Brachytherapy has been held to a higher standard. For example, radiation source location has to be documented and confirmed, whereas with IGRT we rely on an x-ray film or CBCT for target treatment, but there is no confirmation or documentation that the radiation itself was delivered to the intended location (…patient movement, breathing motion, machine malfunction, etc.) When evaluating IGRT treatment delivery, one relies on clinical outcome and untoward results. In brachytherapy, for the majority of the time the applicator and, therefore, the sources, will move with patient movement. The treatment site is still receiving the intended dose. It is worth mentioning that brachytherapy has been using image-guided technology for several decades, long before IGRT and, for the reasons stated above, is also a target-tracking modality. Other advantages of brachytherapy are reduced risk of radiation-induced cancer (less stray radiation and no neutrons), and better dose limitation to OARs. On the reimbursement side in the US, brachytherapy has been treated unfairly. For similar treatment, brachytherapy has seen relatively unattractive low reimbursement. Because of its long and proud history of excellent outcomes, it is simply a matter of time before common sense and fairness will convince the decision makers to allocate the largest piece of the pie to the most deserving modality, brachytherapy. In a bundled system of reimbursement, brachytherapy is the obvious winner because it has provided better value as defined by parameters such as quality, patient experiences, and cost. When compared to other modalities, brachytherapy is a very cost-effective, medically efficacious, and efficient treatment. In a well-designed clinical trial, brachytherapy will undoubtedly surpass external beam with IGRT. The late Dr. Peter Grimm had an ongoing comparison for prostate treatment using all modalities that demonstrated the superiority of brachytherapy over EBRT and surgery for all groups (low, intermediate and high risk patients).8 It also showed that spending more does not provide a better outcome. Treatment selection by healthcare providers is sometimes made, for obvious reasons, on a better reimbursement and not on best available evidence. As healthcare policies become more scrutinized and the focus is on cost efficiency and proven outcome, brachytherapy will not only survive but will become the obvious choice of treatment for several body sites. Brachytherapy has significantly declined for numerous reasons, but mainly due to the rise of SBRT and image guidance providing tangible benefits to the patients, delivering treatment with minimally invasive procedures, and no uncertainty typically inherent to brachytherapy applications. Other reasons include high cost of maintaining radioactive materials licensing and material security, lack of training and/or time investment of professionals to maintain expertise and competency with brachytherapy technologies/techniques, and patient comfort. My opponent argues that brachytherapy has been unfairly burdened with a higher standard for medical event reporting. He also argues that, for SBRT, pre-treatment imaging, and positioning verification is not sufficient to ensure dose delivery to the target, in light of patient motion or machine malfunction. I respectfully reject the suggestion that SBRT with on-board imaging is akin to a lottery in terms of delivery accuracy. The shift toward SBRT is due to its ability to effectively control tumors with minimal normal tissue complications, when delivered properly. However, this argument also neglects advancements in imaging technology, such as 4D CT, optical monitoring, active tumor tracking, and transit dosimetry, among others. While still relatively new, these technologies can alleviate concerns about patient motion (inter- and intra-fraction) and machine functionality. In many ways, these are better able to ensure accurate dose delivery than what is available for brachytherapy for which preliminary attempts to perform positioning verification during treatment are not being used clinically, although they are under development. We also support the development of a well-designed, prospective, randomized trial to compare brachytherapy and SBRT outcomes for disease sites traditionally treated with brachytherapy. These data do not exist and should be a question that our community addresses to offer the utmost care with the least intrusion and discomfort to patients. We do not know which modality is best, or exactly how much better one is than the other. Debates such as this are useful in spurring thought but, ultimately, comparisons are only speculative until real clinical data can help guide the standard of care. To conclude, the answer to the question of whether the use of brachytherapy is declining is an overwhelming yes. At this time, we have little prospective evidence that brachytherapy offers superior outcomes to IGRT. Establishing the relative efficacy between these two modalities should be an important goal of future research. For LDR prostate brachytherapy, I would urge my colleague to look more closely at the prostate radiotherapy paper by Grimm, et al.:8 They concluded that "brachytherapy approaches provide superior outcome in patients with low-risk disease." Furthermore, Petereit et al.4 had the following statements: "…brachytherapy can be considered the ultimate form of conformal radiation therapy because it is unparalleled in its ability to direct a large dose of radiation to the tumor while minimizing exposure to surrounding sensitive normal structures" and "reimbursement for IMRT is markedly higher compared with that for brachytherapy." Also, when looking at Mahmood's reference,2 I could not help noticing the mention of higher reimbursement for EBRT compared with brachytherapy (a common theme!). Several arguments of my colleague seem to be based on perception and not facts. Frank et al.9 addressed these items and concluded that brachytherapy provides the best value when evaluation of outcomes is based on sexual function, urinary problems, bowel function, biochemical relapse-free survival, and cost factors. In summary, because of the superior outcomes and efficient treatments provided by brachytherapy, it is simply a matter of time and common sense before most practitioners will come back to the right choice. Those who have chosen to temporarily abandon it will have some catching up to do! Dr. Parsai wishes to thank Drs. Changhu Chen and Krishna Reddy for helpful discussions. The authors have no relevant conflicts of interest to disclose.
Год издания: 2017
Авторы: E Parsai, Zoubir Ouhib, Colin G. Orton
Издательство: Wiley
Источник: Medical Physics
Ключевые слова: Advanced Radiotherapy Techniques, Hepatocellular Carcinoma Treatment and Prognosis, Breast Cancer Treatment Studies
Другие ссылки: Medical Physics (PDF)
Medical Physics (HTML)
PubMed (HTML)
Medical Physics (HTML)
PubMed (HTML)
Открытый доступ: bronze
Том: 44
Выпуск: 2
Страницы: 351–354