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Clinical Oncology (Royal College of... Aug 2002Coronary artery disease is the leading cause of mortality in the West with over 1.2 million angioplasties performed annually. Despite the introduction of stents,... (Review)
Review
Coronary artery disease is the leading cause of mortality in the West with over 1.2 million angioplasties performed annually. Despite the introduction of stents, restenosis occurs in 30-40% of vessels, which until recently has only been treated effectively by coronary artery bypass surgery. Coronary artery brachytherapy appears to provide an alternative, less invasive remedy. The mechanisms of restenosis and how these are inhibited by radiation are described here. The practicalities of radiation delivery and the history of the development of intravascular radiation as an effective clinical tool are outlined. Finally, the pitfalls of the current technology and the areas in which future research must be targeted for the field to develop are discussed.
Topics: Angioplasty, Balloon; Brachytherapy; Clinical Trials as Topic; Coronary Disease; Coronary Restenosis; Humans; Stents; Thrombosis
PubMed: 12206645
DOI: 10.1053/clon.2002.0070 -
The British Journal of Radiology Jul 2015This article proposes a combination of californium-252 ((252)Cf) brachytherapy, boron neutron capture therapy (BNCT) and an intracavitary moderator balloon catheter...
OBJECTIVE
This article proposes a combination of californium-252 ((252)Cf) brachytherapy, boron neutron capture therapy (BNCT) and an intracavitary moderator balloon catheter applied to brain tumour and infiltrations.
METHODS
Dosimetric evaluations were performed on three protocol set-ups: (252)Cf brachytherapy combined with BNCT (Cf-BNCT); Cf-BNCT with a balloon catheter filled with light water (LWB) and the same set-up with heavy water (HWB).
RESULTS
Cf-BNCT-HWB has presented dosimetric advantages to Cf-BNCT-LWB and Cf-BNCT in infiltrations at 2.0-5.0 cm from the balloon surface. However, Cf-BNCT-LWB has shown superior dosimetry up to 2.0 cm from the balloon surface.
CONCLUSION
Cf-BNCT-HWB and Cf-BNCT-LWB protocols provide a selective dose distribution for brain tumour and infiltrations, mainly further from the (252)Cf source, sparing the normal brain tissue.
ADVANCES IN KNOWLEDGE
Malignant brain tumours grow rapidly and often spread to adjacent brain tissues, leading to death. Improvements in brain radiation protocols have been continuously achieved; however, brain tumour recurrence is observed in most cases. Cf-BNCT-LWB and Cf-BNCT-HWB represent new modalities for selectively combating brain tumour infiltrations and metastasis.
Topics: Boron Neutron Capture Therapy; Brachytherapy; Brain Neoplasms; Californium; Catheterization; Humans; Phantoms, Imaging; Radiometry; Radiotherapy Dosage
PubMed: 25927876
DOI: 10.1259/bjr.20140829 -
Radiotherapy and Oncology : Journal of... May 2009
Topics: Brachytherapy; Breast Neoplasms; Female; Humans; Radiotherapy Dosage
PubMed: 19427547
DOI: 10.1016/j.radonc.2009.04.012 -
The New England Journal of Medicine Jan 2001
Topics: Angioplasty, Balloon, Coronary; Beta Particles; Brachytherapy; Combined Modality Therapy; Coronary Disease; Device Approval; Gamma Rays; Humans; Platelet Aggregation Inhibitors; Secondary Prevention; Stents; United States; United States Food and Drug Administration
PubMed: 11172159
DOI: 10.1056/NEJM200101253440410 -
Journal of Applied Clinical Medical... May 2018As an alternative to cylindrical applicators, air-inflated balloon applicators have been introduced into high-dose-rate (HDR) vaginal cuff brachytherapy to achieve...
PURPOSE
As an alternative to cylindrical applicators, air-inflated balloon applicators have been introduced into high-dose-rate (HDR) vaginal cuff brachytherapy to achieve sufficient dose to the vagina mucosa as well as to spare organs at risk, mainly the rectum and bladder. Commercial treatment planning systems which employ formulae in the AAPM Task Group No. 43 (TG 43) report do not take into account tissue inhomogeneity. Consequently, the low-density air in a balloon applicator induces different doses delivered to the mucosa from planned by these planning systems. In this study, we investigated the dosimetric effects of the air in a balloon applicator using the Monte Carlo (MC) method.
METHODS
The thirteen-catheter Capri™ applicator by Varian™ for vaginal cuff brachytherapy was modeled together with the Ir-192 radioactive source for the microSelectron™ Digital (HDR-V3) afterloader by Elekta™ using the MCNP MC code. The validity of charged particle equilibrium (CPE) with an air balloon present was evaluated by comparing the kerma and the absorbed dose at various distances from the applicator surface. By comparing MC results with and without air cavity present, dosimetric effects of the air cavity were studied. Clinical patient cases with optimized multiple Ir-192 source dwell positions were also explored. Four treatment plans by the Oncentra Brachy™ treatment planning system were re-calculated with MCNP.
RESULTS
CPE fails in the vicinity of the air-water interface. One millimeter beyond the air-water boundary the kerma and the absorbed dose are equal (0.2% difference), regardless of air cavity dimensions or iridium source locations in the balloon. The air cavity results in dose increase, due to less photon absorption in the air than in water or solid materials. The extent of the increase depends on the diameter of the air balloon. The average increment is 3.8%, 4.5% and 5.3% for 3.0, 3.5, and 4.0 cm applicators, respectively. In patient cases, the dose to the mucosa is also increased with the air cavity present. The point dose difference between Oncentra Brachy and MC at 5 mm prescription depth is 8% at most and 5% on average.
CONCLUSIONS
Except in the vicinity of the air-mucosa interface, the dosimetric difference is not significant enough to mandate tissue inhomogeneity correction in HDR treatment planning.
Topics: Brachytherapy; Female; Humans; Iridium Radioisotopes; Monte Carlo Method; Organs at Risk; Prognosis; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Intensity-Modulated; Vaginal Neoplasms
PubMed: 29493101
DOI: 10.1002/acm2.12298 -
Brachytherapy 2018To propose a workflow that uses ultrasound (US)-measured skin-balloon distances and virtual structure creations in the treatment planning system to evaluate the maximum...
PURPOSE
To propose a workflow that uses ultrasound (US)-measured skin-balloon distances and virtual structure creations in the treatment planning system to evaluate the maximum skin dose for patients treated with Contura Multi-Lumen Balloon applicators.
METHODS AND MATERIALS
Twenty-three patients were analyzed in this study. CT and US were used to investigate the interfractional skin-balloon distance variations. Virtual structures were created on the planning CT to predict the maximum skin doses. Fitted curves and its equation can be obtained from the skin-balloon distance vs. maximum skin dose plot using virtual structure information. The fidelity of US-measured skin distance and the skin dose prediction using virtual structures were assessed.
RESULTS
The differences between CT- and US-measured skin-balloon distances values had an average of -0.5 ± 1.1 mm (95% confidence interval [CI] = -1.0 to 0.1 mm). Using virtual structure created on CT, the average difference between the predicted and the actual dose overlay maximum skin dose was -1.7% (95% CI = -3.0 to -0.4%). Furthermore, when applying the US-measured skin distance values in the virtual structure trendline equation, the differences between predicted and actual maximum skin dose had an average of 0.7 ± 6.4% (95% CI = -2.3% to 3.7%).
CONCLUSIONS
It is possible to use US to observe interfraction skin-balloon distance variation to replace CT acquisition. With the proposed workflow, based on the creation of virtual structures defined on the planning CT- and US-measured skin-balloon distances, the maximum skin doses can be reasonably estimated.
Topics: Brachytherapy; Breast; Breast Neoplasms; Catheters; Female; Humans; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Skin; Tomography, X-Ray Computed; Ultrasonography, Mammary
PubMed: 30236908
DOI: 10.1016/j.brachy.2018.08.010 -
Radiotherapy and Oncology : Journal of... May 1999This study analyzed the feasibility, local control and toxicity in potentially curable patients with esophageal carcinoma treated with a combination of external...
Curative radiotherapy with high-dose-rate brachytherapy boost for localized esophageal carcinoma: dose-effect relationship of brachytherapy with the balloon type applicator system.
BACKGROUND AND PURPOSE
This study analyzed the feasibility, local control and toxicity in potentially curable patients with esophageal carcinoma treated with a combination of external irradiation and high-dose-rate (HDR) brachytherapy using a balloon type applicator system to minimize hot spots on the mucosa.
MATERIALS AND METHODS
During the 9 years, 124 patients with esophageal carcinoma and no apparent extraesophageal spread were treated with 40-60 Gy of external irradiation followed by 8-24 Gy of HDR brachytherapy. The fraction size of brachytherapy was 4-6 Gy. We developed a new applicator with 15 mm external diameter inflatable balloons. The reference point was a point 12.5 mm depth from the mid source. The study end points were local control, late toxicity and palliative effect.
RESULTS
All 124 patients completed the planned radiotherapy. Local control rate was 69/124 (56%). There was a trend toward better local control rate for T1 lesions with increasing dose via brachytherapy. Of 69 patients with local control, treatment-related ulcers occurred in 28 patients, leading to death in four. The incidence of ulcers increased with increasing brachytherapy dose; 1/6 with 12 Gy, 16/43 with 16 Gy, 6/ 12 with 20 Gy, 4/5 with 24 Gy. Esophageal benign strictures occurred in ten patients and in all cases developed from ulcers. The incidence of freedom from dysphagia was not dose-dependent.
CONCLUSION
A combination of external irradiation and HDR brachytherapy with the balloon type applicator was feasible and well tolerated. Although better local control was achieved by a higher dose of brachytherapy, the higher dose caused more severe esophageal injury.
Topics: Adult; Aged; Aged, 80 and over; Brachytherapy; Dose-Response Relationship, Radiation; Esophageal Neoplasms; Female; Humans; Male; Middle Aged; Neoplasm Staging; Prospective Studies; Radiation Dosage; Radiation Injuries; Radiotherapy, High-Energy; Survival Analysis; Ulcer
PubMed: 10435804
DOI: 10.1016/s0167-8140(99)00040-7 -
Circulation. Cardiovascular... Oct 2018
Topics: Angioplasty, Balloon, Coronary; Brachytherapy; Drug-Eluting Stents
PubMed: 30354643
DOI: 10.1161/CIRCINTERVENTIONS.118.007365 -
Cardiovascular Radiation Medicine 1999A phosphorus-32-impregnated balloon angioplasty catheter was used in a novel technique of simultaneous angioplasty and vessel irradiation. The 32P radionuclides were...
PURPOSE
A phosphorus-32-impregnated balloon angioplasty catheter was used in a novel technique of simultaneous angioplasty and vessel irradiation. The 32P radionuclides were distributed on the surface of the balloon so that a certain amount of radiation was delivered while angioplasty was performed. Three-dimensional dosimetry and dose-time relationship needs to be established for the catheter so that quantitative dosimetric information is available for both clinical treatment and research investigation.
METHODS AND MATERIALS
The 32P-impregnated balloon of an angioplasty catheter was assumed to have a cylindrical shape, and the radionuclides were assumed to be distributed uniformly on the curved surface of the cylinder. The dose rate at a point in space was computed by integrating the point dose-rate kernel of 32P over the radioactive surface of the balloon. The point dose-rate kernel was computed with Monte Carlo simulation of radiation transport. The energy spectra of 32P based on a mathematical model was used in the calculations. The three-dimensional dose distributions and dose-time relationships were calculated for balloons of various lengths and radii.
RESULTS
At a short radial distance (e.g., 0.2 mm) away from the balloon surface, the dose distribution was uniform across a large portion of the balloon along the longitudinal axis, and dropped off rapidly at both ends of the balloon. Uniformity became worse as the radial distance increased. Uniformity was almost independent of balloon radius. The underdosed length at each end of the balloon was also almost independent of balloon length. In the central transverse plane, the dose reached a maximum at the surface of the balloon and then dropped off rapidly as the distance increases. Relative dose coverage outside the balloon was approximately independent of balloon radius and length, and the absolute dose coverage was approximately inversely proportional to balloon radius and length, assuming same total activity.
CONCLUSIONS
Point dose-rate kernel of 32P beta emitter and the three-dimensional dose distributions of a 32P-impregnated balloon from an novel angioplasty catheter were calculated. A rule of thumb for dose calculation and dose coverage was established for simultaneous angioplasty and vascular brachytherapy with a 32P-impregnated balloon catheter.
Topics: Angioplasty, Balloon; Brachytherapy; Humans; Models, Theoretical; Phosphorus Radioisotopes; Radiometry
PubMed: 10828565
DOI: 10.1016/s1522-1865(00)00022-6 -
Catheterization and Cardiovascular... Nov 2022
Topics: Humans; Coronary Restenosis; Brachytherapy; Treatment Outcome; Stents; Angioplasty, Balloon, Coronary; Constriction, Pathologic; Coronary Angiography
PubMed: 36378732
DOI: 10.1002/ccd.30462