Can increasing the dose of radiation by HDR brachytherapy boost following pre operative chemoradiotherapy for advanced rectal cancer improve surgical outcomes?

Myint, Arthur Sun; Mukhopadhyay, Tanmoy; Ramani, V. S.; Perkins, Kate; Snee, A. J.; Jelley, F.E.; Wong, Helen; Lee, C. D.

doi:10.1111/j.1463-1318.2010.02322.x

Cited by 30 publications

(18 citation statements)

References 17 publications

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“…Preoperative radiochemotherapy administered concomitantly with 5-fluorouracil has become the standard of care in rectal cancer, especially in tumors of the lower and middle rectum [2]. Recently, high dose rate endorectal brachytherapy has emerged as an alternative neoadjuvant treatment for low-lying rectal cancer [3-5]. In our previous study, we found that brachytherapy with low dose 125-iodine ( 125 I) seeds could serve as an effective salvage therapy for recurring rectal cancer [6].…”

Section: Introductionmentioning

confidence: 99%

Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

Liu

Wang

et al. 2013

Radiat Oncol

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BackgroundTo characterize the effect of combined treatment of the anti-epidermal growth factor receptor (EGFR) monoclonal antibody C225 and 125-iodine (125I) seed radiation in human colorectal cancer.MethodsWe treated LS180 cells with 125I continuous low dose rate radiation in the presence and absence of 100 nM C225. The clonogenic capacity, cellular proliferation, cell cycle distribution, apoptosis, and molecular pathways of the cells following the treatments were analyzed in vitro.ResultsThe sensitizer enhancement ratio of C225 was approximately 1.4. Treatment with C225 and radiation alone produced significant inhibition of cell growth, but combination therapy produced greater inhibition than either treatment administered alone. C225 increased the radiation-induced apoptosis and the fraction of γ-H2AX foci positive cells at 48 h after treatment. The Akt phosphorylation level was lower in the cells receiving the combination treatment than in the cells treated with radiation or C225 alone.ConclusionsThese findings indicate that C225 sensitizes LS180 cells to 125I seed radiation. Growth inhibition is mediated by inducing apoptosis and not cell cycle arrest. Additionally, we confirmed that C225 impairs DNA repair by reducing the cellular level of the DNA-PKcs and Ku70 proteins. Furthermore, the inhibition of Akt signaling activation may be responsible for the C225-mediated radiosensitization.

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Section: Introductionmentioning

confidence: 99%

Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

Liu

Wang

et al. 2013

Radiat Oncol

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“…There is evidence that increasing the dose of radiation improves the local control, and brachytherapy can be used to achieve this. [117][118][119] For radical treatments, a flexible multichannel applicator can be used with either simple 2D techniques using digital X-ray fluoroscopic imaging for planning or full 3D CT/MRI. The simple 2D technique is based on using the standard applicator geometry and prescribing to a distance of typically 10 mm from the applicator surface.…”

Section: 103mentioning

confidence: 99%

Recent developments and best practice in brachytherapy treatment planning

Lee

2014

BJR

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Brachytherapy has evolved over many decades, but more recently, there have been significant changes in the way that brachytherapy is used for different treatment sites. This has been due to the development of new, technologically advanced computer planning systems and treatment delivery techniques. Modern, three-dimensional (3D) imaging modalities have been incorporated into treatment planning methods, allowing full 3D dose distributions to be computed. Treatment techniques involving online planning have emerged, allowing dose distributions to be calculated and updated in real time based on the actual clinical situation. In the case of early stage breast cancer treatment, for example, electronic brachytherapy treatment techniques are being used in which the radiation dose is delivered during the same procedure as the surgery. There have also been significant advances in treatment applicator design, which allow the use of modern 3D imaging techniques for planning, and manufacturers have begun to implement new dose calculation algorithms that will correct for applicator shielding and tissue inhomogeneities. This article aims to review the recent developments and best practice in brachytherapy techniques and treatments. It will look at how imaging developments have been incorporated into current brachytherapy treatment and how these developments have played an integral role in the modern brachytherapy era. The planning requirements for different treatments sites are reviewed as well as the future developments of brachytherapy in radiobiology and treatment planning dose calculation. CHANGES AND DEVELOPMENTS IN TREATMENT PLANNING TECHNIQUESWithin the past few decades, there have been some major changes to the way brachytherapy treatments are both planned and delivered, and the introduction of modern, three dimensional (3D) imaging techniques have contributed significantly. In the 1930s, before the advent of planning computers, treatment planning was carried out by simply following a set of rules according to a dosimetry system such as the Manchester system. [1][2][3] This system was originally developed for use with radium sources and provided information, in tabular form, for the dose specification and distribution of sources and was used for many years. An increase in radiation safety awareness in the 1970s and 1980s led to a decline in the use of radium in favour of the relatively newer and safer radioisotopes such as caesium-137 and iridium-192. Over the same period, technological advances in afterloading techniques and the wider implementation of computerized planning using planar radiographic imaging were being implemented in an attempt to verify the applicator or catheter positions and calculate patient-specific dose. Alongside these advances, the need to compare patients' treatments with those from other treatment centres was being recognized as an important scientific standardization of treatment. The International Commission on Radiation Units and Measurements (ICRU) reports 38 and 58, 4,5 details t...

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“…The ICMA was chosen as a baseline point of comparison because it is a widely used rectal applicator and has the most promising dosimetric results. [5][6][7][8][9][10][11] The ICMA system is composed of a flexible silicon applicator, 280-mm in length, and 20-mm in diameter. See Fig.…”

Section: D Reference Applicators (Icma and Dmbt)mentioning

confidence: 99%

“…Various studies have shown that preoperative high-dose rate (HDR) brachytherapy, instead of the typical preoperative CRT, has proven to be quite beneficial in recurrence rates and long-term survival. [5][6][7] The most exciting improvements have come from use of the intracavitary mold applicator (ICMA) (Nucletron, Netherlands), [8][9][10][11] which is an eight-channel cylindrical applicator. When using this applicator, the occurrence of grade ≥3 acute proctitis went down to 1% vs 27%, and pathologic complete response rate rose to 29% compared with 8%-12% using CRT.…”

Section: Introductionmentioning

confidence: 99%

“…One reason for large benefits seen from this applicator is the optional shielding, which is in the form of an 8-mm diameter tungsten rod, which can be used for treatment of noncircumferential tumors. 10 While the tungsten allows for some dose anisotropy, the geometry of the design places the 192 Ir seed 2.5-mm away from the shield surface, resulting in a 285 • spread of completely unshielded cross-sectional dose, 6 thus limiting how conformal the delivered radiation profile can be. Therefore, while outcomes with the ICMA have been very encouraging, there still exists a large potential for improvement in dose congruence.…”

Section: Introductionmentioning

confidence: 99%

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HDR brachytherapy of rectal cancer using a novel grooved‐shielding applicator design

et al. 2013

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Can increasing the dose of radiation by HDR brachytherapy boost following pre operative chemoradiotherapy for advanced rectal cancer improve surgical outcomes?

Cited by 30 publications

References 17 publications

Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

Combined effects of C225 and 125-iodine seed radiation on colorectal cancer cells

Recent developments and best practice in brachytherapy treatment planning

HDR brachytherapy of rectal cancer using a novel grooved‐shielding applicator design

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