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BMC Research Notes Feb 2023In this study, it was aimed to evaluate the functionality to deliver different prescription dose except 20 Gy for the Xoft Axxent Ebt (electronic Brachytherapy) system...
PURPOSE
In this study, it was aimed to evaluate the functionality to deliver different prescription dose except 20 Gy for the Xoft Axxent Ebt (electronic Brachytherapy) system and analyzing the system in terms of radiation dosimetry in water and 0.9% isotonic Sodium Chloride (NaCl) solution.
MATERIALS AND METHODS
In the Xoft Axxent eBT, different prescription dose in single fraction were calculated for different balloon applicator volumes based on source position and irradiation times. EBT-XD Gafchromic film was calibrated at 6MV photon energy. A balloon applicator filled with 0.9% isotonic NaCl solution was used to deliver a radiation dose of 20 Gy, 16 Gy, 10 Gy on the applicator surface. Then the balloon applicator was filled with water and the same measurements were repeated. Finally, the balloon applicator was irradiated by positioning it at different distances in the water phantom to simulate the isodose contour.
RESULTS
At the time the balloon applicator was filled with water and 0,9% NaCl solution, the difference between the planned dose and the absorbed dose was ~ 2% vs. 15% for 30 cc, ~ 5% vs. 14% for 35 cc and ~ 3,5% vs. 10% for 40 cc respectively. Finally, the absorbed dose at a distance of 1 cm from the applicator surface was measured as 9.63 Gy.
CONCLUSION
In this study, it was showed that different prescription dose could be possible to deliver in the Xoft Axxent eBT system based on the standard plan. In addition, the absorbed dose was higher than the planned dose depending on the effective atomic number of NaCl solution comparing to water due to photoelectric effect in low energy photons. By measuring the dose distributions at different distances from the balloon applicator surface, the absorbed dose in tissue equivalent medium was determined and the isodose contours characteristics was simulated.
Topics: X-Rays; Sodium Chloride; Radiography; Saline Solution; Water; Radiation Dosage
PubMed: 36855193
DOI: 10.1186/s13104-023-06287-1 -
Clinical Cardiology Jun 2011It has been reported that drug-eluting stents (DES) were superior to intracoronary brachytherapy (ICBT) in patients with in-stent restenosis (ISR). However, it is... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
It has been reported that drug-eluting stents (DES) were superior to intracoronary brachytherapy (ICBT) in patients with in-stent restenosis (ISR). However, it is unknown whether there might be differences between DES and ICBT in terms of efficacy and safety in large sample size and long-term follow-up.
HYPOTHESIS
The aim of this study was to determine whether DES implantation remains favorable in large sample size and long-term follow-up when compared with ICBT among patients with ISR.
METHODS
We conducted a search in MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials without language restrictions. A meta-analysis of 1942 cases from 12 controlled trials of DES vs ICBT for ISR was performed.
RESULTS
Drug-eluting stents were significantly more effective in reducing target-vessel revascularization (TVR) (odds ratio [OR]: 0.44, 95% confidence interval [CI]: 0.23-0.81, P = 0.009) and binary restenosis (OR: 0.34, 95% CI: 0.26-0.46, P<0.00001) compared with ICBT at midterm follow-up. There were no significant differences between DES and ICBT in cardiac death, myocardial infarction (MI), and late stent thrombosis at midterm follow-up. A statistical significance has been found between the 2 groups in TVR (OR: 0.61, 95% CI: 0.43-0.86, P = 0.005) at long-term follow-up. There were no significant differences in cardiac death and MI between the 2 groups at long-term follow-up.
CONCLUSIONS
These findings provide evidence that DES is superior to ICBT for the treatment of ISR in TVR and binary restenosis reduction, but not in cardiac death, MI, and late stent thrombosis reduction. © 2011 Wiley Periodicals, Inc. Yong-Guang Lu, MD, and Yan-Mei Chen, MD, contributed equally to this work. The authors have no funding, financial relationships, or conflicts of interest to disclose.
Topics: Aged; Angioplasty, Balloon, Coronary; Brachytherapy; Chi-Square Distribution; Coronary Restenosis; Coronary Stenosis; Coronary Thrombosis; Drug-Eluting Stents; Female; Humans; Male; Middle Aged; Myocardial Infarction; Odds Ratio; Prosthesis Design; Risk Assessment; Risk Factors; Time Factors; Treatment Outcome
PubMed: 21538389
DOI: 10.1002/clc.20900 -
Technology in Cancer Research &... Dec 2017To assess the dosimetric flexibility of a dual balloon brachytherapy applicator developed for the treatment of anorectal lesions.
BACKGROUND AND PURPOSE
To assess the dosimetric flexibility of a dual balloon brachytherapy applicator developed for the treatment of anorectal lesions.
MATERIALS AND METHODS
Different amounts of water were infused into the inner and outer balloon separately to study the asymmetrical distribution of the catheter, the radial distance of the active source channel to the inner surface of the global target volume , the space between the active source channels, and their dosimetric impact to target tissues and uninvolved rectum.
RESULTS
Increasing inner balloon volume directly increased both the space between the active source channels and the radial distance of the active source channel to the inner surface of the global target volume. The space between the active source channels and the percentage of global target volume received 150% or more of the prescribed dose to target had a strong inverse correlation (-0.881/ = .007, -0.976/ = .001, respectively) with the radial distance of the active source channel to the inner surface of the global target volume. Conformity index, dose to 2 cm of rectum, and total reference air kerma were strongly correlated with the radial distance of the active source channel to the inner surface of the global target volume, with values of 0.952 ( = .001), 0.833 ( = .015), and 0.922 ( = .002), respectively. Percentage of global target volume received 150% or more of the prescribed dose was significantly correlated with the space between the active source channels (0.81/ = .022), and conformity index was strongly inversely correlated with the space between the active source channels (-0.833/ = .015).
CONCLUSION
The dual balloon-constructed Anorectal Applicator offers a flexible way to adjust the distances of the active source positions to the target in relation to uninvolved rectal wall. This flexibility simplifies planning which results in a highly conformal dose distribution to the target lesion while minimizing dose to normal rectal tissue.
PubMed: 28481175
DOI: 10.1177/1533034617707433 -
Radiologia Brasileira 2016To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with (99m)Tc and balloon brachytherapy with high-dose-rate...
OBJECTIVE
To perform a comparative dosimetric analysis, based on computer simulations, of temporary balloon implants with (99m)Tc and balloon brachytherapy with high-dose-rate (HDR) (192)Ir, as boosts to radiotherapy. We hypothesized that the two techniques would produce equivalent doses under pre-established conditions of activity and exposure time.
MATERIALS AND METHODS
Simulations of implants with (99m)Tc-filled and HDR (192)Ir-filled balloons were performed with the Siscodes/MCNP5, modeling in voxels a magnetic resonance imaging set related to a young female. Spatial dose rate distributions were determined. In the dosimetric analysis of the protocols, the exposure time and the level of activity required were specified.
RESULTS
The (99m)Tc balloon presented a weighted dose rate in the tumor bed of 0.428 cGy.h(-1).mCi(-1) and 0.190 cGyh(-1).mCi(-1) at the balloon surface and at 8-10 mm from the surface, respectively, compared with 0.499 and 0.150 cGyh(-1).mCi(-1), respectively, for the HDR (192)Ir balloon. An exposure time of 24 hours was required for the (99m)Tc balloon to produce a boost of 10.14 Gy with 1.0 Ci, whereas only 24 minutes with 10.0 Ci segments were required for the HDR (192)Ir balloon to produce a boost of 5.14 Gy at the same reference point, or 10.28 Gy in two 24-minutes fractions.
CONCLUSION
Temporary (99m)Tc balloon implantation is an attractive option for adjuvant radiotherapy in breast cancer, because of its availability, economic viability, and similar dosimetry in comparison with the use of HDR (192)Ir balloon implantation, which is the current standard in clinical practice.
PubMed: 27141131
DOI: 10.1590/0100-3984.2015.0010 -
Diagnostics (Basel, Switzerland) Sep 2022Peripheral arterial disease (PAD) is an increasingly pathological condition that commonly affects the femoropopliteal arteries. The current fashionable treatment is... (Review)
Review
Peripheral arterial disease (PAD) is an increasingly pathological condition that commonly affects the femoropopliteal arteries. The current fashionable treatment is percutaneous transluminal angioplasty (PTA), often with stenting. However, the in-stent restenosis (ISR) rate after the stenting of the femoropopliteal (FP) district remains high. Many techniques have been proposed for the treatment of femoropopliteal ISR, such as intravascular brachytherapy, laser atherectomy, second stenting and drug-coated balloons angioplasty (DCB). DCB showed a significantly lower rate of restenosis and target lesions revascularization (TLR) compared to conventional PTA. However, further studies and multi-center RCTs with dedicated long-term follow-up are needed to verify the true efficiency of this approach. Nowadays, the correlation between PAD and inflammation biomarkers is well known. Multiple studies have shown that proinflammatory markers (such as C-reactive proteins) and the high plasma levels of microRNA could predict the outcomes after stent placement. In particular, circulating microRNA-320a, microRNA-3937, microRNA-642a-3p and microRNA-572 appear to hold promise in diagnosing ISR in patients with PAD, but also as predictors of stent patency. This narrative review intends to summarize the current knowledge on the value of circulating biomarkers as predictors of ISR and to foster the scientific debate on the advantages of using DCB in the treatment of ISR in the FP district.
PubMed: 36140608
DOI: 10.3390/diagnostics12092207 -
Japanese Heart Journal Sep 2000One of the most intriguing developments in recent years towards prevention of restenosis after angioplasty is the use of ionizing radiation. The background for the use... (Review)
Review
One of the most intriguing developments in recent years towards prevention of restenosis after angioplasty is the use of ionizing radiation. The background for the use of radiation treatment for this application is sound, since radiation is used not only to treat malignant cancerous growths but also is used for treatment of benign hyperplastic disorders such as post-surgical keloid formation and recurrence of pterygium after surgical removal. Restenosis can be considered a form of overexuberant wound healing triggered by angioplasty. Ionizing radiation inhibits serum-stimulated proliferation of many cell types including fibroblasts and smooth muscle cells in vitro and also suppresses the synthesis of collagen by cultured fibroblasts. Liermann who showed inhibition of post-stent restenosis first used ionizing radiation for restenosis prevention clinically in iliac and iliofemoral arteries. Subsequently, extensive animal studies in various restenosis models have shown a profound inhibitory effect of catheter-based radiation (endovascular brachytherapy) on neointima formation and overall vessel shrinkage (negative remodeling). Based on these results clinical trials have been initiated with several types of devices and isotopes. Among these are 192Ir, 32P, 90Y, 90Sr/Y and 188Re. Additionally, radioactive stents have been developed; devices for clinical use are made radioactive at the microCi level by surface implantation of 32P ions. Results from early clinical trials are encouraging and brachytherapy appears safe for clinical use and at an appropriate dose, may be highly effective for restenosis prevention.
Topics: Angioplasty, Balloon; Angioplasty, Balloon, Coronary; Animals; Brachytherapy; Clinical Trials as Topic; Constriction, Pathologic; Coronary Disease; Coronary Vessels; Disease Models, Animal; Endothelium, Vascular; Humans; Recurrence; Stents
PubMed: 11132163
DOI: 10.1536/jhj.41.541 -
Journal of Cancer Research and... 2011To explore the dosimetric advantages of the new MammoSite multilumen (ML) balloon for breast brachytherapy treatment compared to conventional single lumen (SL) device...
PURPOSE
To explore the dosimetric advantages of the new MammoSite multilumen (ML) balloon for breast brachytherapy treatment compared to conventional single lumen (SL) device plan.
MATERIALS AND METHODS
Patients deemed appropriate for accelerated partial breast irradiation (APBI) were implanted with the MammoSite ML balloon. Two plans were generated in each patient for the same target coverage (PTV_EVAL) and dose to normal structures were plotted. The first plan used only the central single lumen with single-dwell position (SL), and the second plan (ML) was generated using the other lumens of the device. Dose distributions of the SL and ML plans were compared.
RESULTS
For the same PTV_EVAL, the ML balloon improved dose coverage at the tip and base of the applicator compared to SL plan. The skin and rib doses were reduced using the ML plan versus SL plan for the same PTV_EVAL in-patient 2, where the skin-balloon distance was 7 mm and the rib-balloon distance was <1 cm. For patient 1, the skin and rib distances were greater than 1 cm and the ML plan did not further minimize the dose to normal structures.
CONCLUSION
In our initial experience, dosimetric goals can be better achieved using the ML MammoSite balloon when normal structures (skin and ribs) are close to PTV_EVAL with a distance of <7 mm and rib distance of <1 cm. The multiple lumen of ML balloon can optimize dose and reduce excessive dose to rib and skin and therefore minimize the long-term toxicities of rib discomfort, skin fibrosis and fat necrosis.
Topics: Brachytherapy; Breast Neoplasms; Catheterization; Catheters; Dermatologic Surgical Procedures; Female; Humans; Mastectomy, Segmental; Prognosis; Radiometry; Radiotherapy Planning, Computer-Assisted; Skin
PubMed: 21546745
DOI: 10.4103/0973-1482.80469 -
Journal of Medical Physics Jan 2009Multiple fractions of High Dose Rate (HDR) brachytherapy along with external beam therapy is the common method of treatment for cancer of the uterine cervix. Urinary...
Multiple fractions of High Dose Rate (HDR) brachytherapy along with external beam therapy is the common method of treatment for cancer of the uterine cervix. Urinary bladder and rectum are the organs at risk (OARs) that receive a significant dose during treatment. To reduce the dose to these organs, a majority of hospitals use vaginal gauze packing, as it is a simple, nontraumatic, and easy method. This article describes the design and development of an inflatable balloon that can be used along with the applicator as a substitute for gauze packing. The balloon has two parts-the bladder part (B-part) and the rectum part (R-part), both of them are independently inflatable. The selection of the material, its width, length, and thickness are described. A mould/former for making the balloon was designed. Polished steel was used as the mould. This was dipped in specially prepared natural rubber latex (NRL) solution several times; the layers were dried and stripped to get the balloon. The composition of NRL and the compounding recipe of the latex are also described. Physical tests like tensile strength, elongation at break, bursting volume, and radiation attenuation caused by the balloon, were checked. Biological tests for assessing type I and type IV allergies, like dermal irritation and skin irritation tests, were also done.
PubMed: 20126566
DOI: 10.4103/0971-6203.48721 -
Radiation Oncology (London, England) Jul 2015Accelerated partial breast irradiation (APBI) with balloon and strut adjusted volume implants (SAVI) show promising results with excellent tumor control and minimal... (Comparative Study)
Comparative Study
PURPOSE
Accelerated partial breast irradiation (APBI) with balloon and strut adjusted volume implants (SAVI) show promising results with excellent tumor control and minimal toxicity. Knowing the factors that contribute to a high skin dose, rib dose, and D95 coverage may reduce toxicity, improve tumor control, and help properly predict patient outcomes following APBI.
METHODS AND MATERIALS
A retrospective analysis of 594 patients treated with brachytherapy based APBI at a single institution from May 2008 to September 2014 was grouped by applicator subtype. Patients were treated to a total of 34 Gy (3.4 Gy x 10 fractions over 5 days delivered BID) targeting a planning target volume (PTV) 1.0 cm beyond the lumpectomy cavity using a high dose rate source.
RESULTS
SAVI devices had the lowest statistically significant values of DmaxSkin (81.00 ± 29.83), highest values of D90 (101.50 ± 3.66), and D95 (96.09 ± 4.55). SAVI-mini devices had the lowest statistically significant values of DmaxRib (77.66 ± 32.92) and smallest V150 (18.01 ± 3.39). Multi-lumen balloons were able to obtain the smallest V200 (5.89 ± 2.21). Strut-based applicators were more likely to achieve a DmaxSkin and a DmaxRib less than or equal to 100 %. The effect of PTV on V150 showed a strong positive relationship (p < .001). PTV and DmaxSkin showed a weak negative relationship in multi-lumen applicators (p = .016) and SAVI-mini devices (p < .001). PTV and DmaxRib showed a weak negative relationship in multi-lumen applicators (p = .009), SAVI devices (p < .001), and SAVI-mini devices (p < .001).
CONCLUSION
PTV volume is strongly correlated with V150 in all devices and V200 in strut based devices. Larger PTV volumes result in greater V150 and V200, which could help predict potential risks for hotspots and resulting toxicities in these devices. PTV volume is also weakly negatively correlated with max skin dose and max rib dose, meaning that as the PTV volumes increase one can expect slightly smaller max skin and rib doses. Strut based applicators are significantly more effective in keeping skin and rib dose constraints under 125 and 100 % when compared to any balloon based applicator.
Topics: Adult; Aged; Aged, 80 and over; Brachytherapy; Breast Neoplasms; Catheters; Dose Fractionation, Radiation; Equipment Design; Female; Humans; Mastectomy, Segmental; Middle Aged; Organs at Risk; Radiation Injuries; Radiometry; Radiotherapy, Adjuvant; Retrospective Studies; Ribs; Skin; Tumor Burden
PubMed: 26227388
DOI: 10.1186/s13014-015-0468-7 -
Clinical Cardiology Jul 2002The problem of restenosis after percutaneous transluminal coronary angioplasty remains the major limiting factor of the procedure. Over the last 10 years, investigators... (Review)
Review
The problem of restenosis after percutaneous transluminal coronary angioplasty remains the major limiting factor of the procedure. Over the last 10 years, investigators have been studying the use of radiation therapy for preventing restenosis after angioplasty or stent placement. Since radiotherapy has been proven in other cases to be effective in disrupting the cell cycle regulatory proteins and thereby slowing or stopping growth, it was decided to apply the same principle to neointimal hyperplasia. To review the data that have emerged regarding vascular radiation with an emphasis on irradiated stents, 65 articles were reviewed and both preclinical and clinical experiments were included. Overall, studies with gamma and beta radiation show promising results. Endovascular gamma radiation has been shown effective in randomized trials, even at 3-year follow-up. Beta radiation is preferred because of greater safety and localization, and because it has also shown encouraging results in initial clinical trials, as well as in larger randomized studies. Consequently, the Federal Drug Administration has approved the use of both. In both types of endovascular brachytherapy, it seems the greater the dose, the better the initial response. Safety concerns include an increased incidence of late thrombosis and greater restenosis at margins. With irradiated stents, however, the situation is not as clear. At times, animal models have presented confusing results. These have ranged from significant suppression of hyperplasia to outright adverse effects of radiation on the vessel wall. While some clinical trials have been encouraging, others have not. Follow-up of up to 1 year has been disappointing so far. Many issues, such as the "candy wrapper" effect and rebound hyperplasia, must be dealt with before this becomes a viable form of therapy. It has become clear that radiation therapy in this setting, while having potentially great benefits, can cause deleterious effects as well. However, the mixed bag of positive and negative results seen so far, and the attractiveness of stents or percutaneous transluminal coronary angioplasty being "restenosis-proofed," eventually is cause for cautious optimism.
Topics: Angioplasty, Balloon, Coronary; Animals; Beta Particles; Brachytherapy; Cardiac Catheterization; Coronary Artery Disease; Coronary Restenosis; Gamma Rays; Humans; Radiation Injuries, Experimental; Stents
PubMed: 12109864
DOI: 10.1002/clc.4950250703