The prostate, planning target volume, femoral heads, rectum and bladder are contoured in green, purple, red, yellow, and brown, respectively. An axial slice from a computed tomography image for each plan is included. įigure 1 Dosimetric comparison of intensity-modulated radiation therapy and passive-scattering proton therapy. Multiple dosimetric comparisons have been performed evaluating the extent of the dosimetric improvements that PT offers for prostate cancer and, in general, they have shown that PT reduces the dose of excess radiation provided to OARs in the low-to-moderate range. For many target locations, these features reduce the excess radiation dose delivered to surrounding organs and the number of beams needed to treat a target when compared to photon radiation ( Figure 1). Additionally, the entrance dose is relatively low when compared to external-beam photon radiation. Protons travel only a finite distance, proportional to their speed, which can be controlled during the acceleration process they deposit most of their energy at the end of their range in an area called the “Bragg peak” and, unlike photon-based radiation, there is no exit dose beyond the target. The potential advantages and disadvantages of PT result from its dosimetric features. Potential advantages and disadvantages of PT
This review will summarize the dosimetric advantages of PT compared with photon-based conventional radiation techniques (such as IMRT), its cost, cost effectiveness, and supporting literature for PT in the management of prostate cancer. Specifically, the medical community has called for comparative effectiveness studies to determine whether PT improves the therapeutic ratio in the management of prostate cancer when compared to other less-expensive treatment modalities. Since PT is more expensive than other radiation therapy techniques, like brachytherapy and IMRT ( 5), physicians, patients, and other stakeholders are interested in high-quality evidence supporting PT in the management of prostate cancer. Over the past decade, a number of new proton centers have opened across the United States, and many have promoted the use of PT in the management of prostate cancer. PT may also reduce the risk for second cancer development and sexual dysfunction when compared to IMRT ( 4). This may translate into lower rates of gastrointestinal (GI) and genitourinary (GU) toxicities in patients being treated for prostate cancer.
PT reduces integral dose of radiation delivered to organs at risk (OARs) surrounding the target ( 1- 3). Protons are charged particles that produce a significantly different dose distribution when compared to photon based radiation therapy techniques, including intensity-modulated radiation therapy (IMRT). Interest in proton therapy (PT) in the management of prostate cancer has steadily increased over the past two decades.
Keywords: Particle therapy genitourinary cancer (GU cancer)
#Disadvantages of proton email trial#
We also review the available cost-effectiveness data for PT and discuss the future of PT, including the current randomized trial comparing PT to intensity-modulated radiation therapy and the need for additional research that may help to establish the relative benefit of PT when compared to photon-based radiation therapy. In this review, we summarize the results of recently published studies that support the safety and efficacy of PT in the treatment of prostate cancer. A number of new PT centers have been built over the past decade, leading many stakeholders, including patients, physicians, and insurers, to demand comparative effectiveness data to support its current use. Nevertheless, its higher costs and the current lack of level I evidence documenting improved clinical outcomes have led some to question its cost-effectiveness. Because of its dosimetric advantages when compared to conventional radiation, PT has the potential to improve the therapeutic ratio in the management of prostate cancer by decreasing toxicity and improving disease control. Abstract: Proton therapy (PT) for prostate cancer has been a subject of controversy over the past two decades.
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