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European Urology Sep 2021Management of locally recurrent prostate cancer after definitive radiotherapy remains controversial due to the perceived high rates of severe genitourinary (GU) and... (Meta-Analysis)
Meta-Analysis Review
CONTEXT
Management of locally recurrent prostate cancer after definitive radiotherapy remains controversial due to the perceived high rates of severe genitourinary (GU) and gastrointestinal (GI) toxicity associated with any local salvage modality.
OBJECTIVE
To quantitatively compare the efficacy and toxicity of salvage radical prostatectomy (RP), high-intensity focused ultrasound (HIFU), cryotherapy, stereotactic body radiotherapy (SBRT), low-dose-rate (LDR) brachytherapy, and high-dose-rate (HDR) brachytherapy.
EVIDENCE ACQUISITION
We performed a systematic review of PubMed, EMBASE, and MEDLINE. Two- and 5-yr recurrence-free survival (RFS) rates and crude incidences of severe GU and GI toxicity were extracted as endpoints of interest. Random-effect meta-analyses were conducted to characterize summary effect sizes and quantify heterogeneity. Estimates for each modality were then compared with RP after adjusting for individual study-level covariates using mixed-effect regression models, while allowing for differences in between-study variance across treatment modalities.
EVIDENCE SYNTHESIS
A total of 150 studies were included for analysis. There was significant heterogeneity between studies within each modality, and covariates differed between modalities, necessitating adjustment. Adjusted 5-yr RFS ranged from 50% after cryotherapy to 60% after HDR brachytherapy and SBRT, with no significant differences between any modality and RP. Severe GU toxicity was significantly lower with all three forms of radiotherapeutic salvage than with RP (adjusted rates of 20% after RP vs 5.6%, 9.6%, and 9.1% after SBRT, HDR brachytherapy, and LDR brachytherapy, respectively; p ≤ 0.001 for all). Severe GI toxicity was significantly lower with HDR salvage than with RP (adjusted rates 1.8% vs 0.0%, p < 0.01), with no other differences identified.
CONCLUSIONS
Large differences in 5-yr outcomes were not uncovered when comparing all salvage treatment modalities against RP. Reirradiation with SBRT, HDR brachytherapy, or LDR brachytherapy appears to result in less severe GU toxicity than RP, and reirradiation with HDR brachytherapy yields less severe GI toxicity than RP. Prospective studies of local salvage for radiorecurrent disease are warranted.
PATIENT SUMMARY
In a large study-level meta-analysis, we looked at treatment outcomes and toxicity for men treated with a number of salvage treatments for radiorecurrent prostate cancer. We conclude that relapse-free survival at 5 years is equivalent among salvage modalities, but reirradiation may lead to lower toxicity.
Topics: Brachytherapy; Cryotherapy; High-Intensity Focused Ultrasound Ablation; Humans; Male; Neoplasm Recurrence, Local; Prospective Studies; Prostatectomy; Prostatic Neoplasms; Radiation Dosage; Radiosurgery; Salvage Therapy
PubMed: 33309278
DOI: 10.1016/j.eururo.2020.11.010 -
Neuro-oncology Nov 2022Brachytherapy remains an underrecognized and underutilized radiation therapy modality for the treatment of spinal tumors. This article summarizes the existing body of...
Brachytherapy remains an underrecognized and underutilized radiation therapy modality for the treatment of spinal tumors. This article summarizes the existing body of medical literature on the usage, indications, techniques, and outcomes of brachytherapy for the treatment of spine tumors. The disease pathology most commonly treated with brachytherapy is metastatic spine cancer, rather than primary bone tumors of the spine. Brachytherapy can be used alone, as percutaneous needle injections; however, it is more often used in conjunction with open surgery or cement vertebral body augmentation. Although the data are still relatively sparse, studies show consistent benefit from brachytherapy in terms of improvements in pain, function, local recurrence rate, and overall survival. Brachytherapy is also associated with a favorable complication profile.
Topics: Humans; Brachytherapy; Spinal Neoplasms; Pain; Treatment Outcome
PubMed: 36322097
DOI: 10.1093/neuonc/noac094 -
Radiotherapy and Oncology : Journal of... Feb 2022This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine...
This is an evidence-based guideline for prostate brachytherapy. Throughout levels of evidence quoted are those from the Oxford Centre for Evidence based Medicine (https://www.cebm.ox.ac.uk/resources/levels-of-evidence/oxford-centre-for-evidence-based-medicine-levels-of-evidence-march-2009). Prostate interstitial brachytherapy using either permanent or temporary implantation is an established and evolving treatment technique for non-metastatic prostate cancer. Permanent brachytherapy uses Low Dose Rate (LDR) sources, most commonly I-125, emitting photon radiation over months. Temporary brachytherapy involves first placing catheters within the prostate and, on confirmation of accurate positioning, temporarily introducing the radioactive source, generally High Dose Rate (HDR) radioactive sources of Ir-192 or less commonly Co-60. Pulsed dose rate (PDR) brachytherapy has also been used for prostate cancer [1] but few centres have adopted this approach. Previous GEC ESTRO recommendations have considered LDR and HDR separately [2-4] but as there is considerable overlap, this paper provides updated guidance for both treatment techniques. Prostate brachytherapy allows safe radiation dose escalation beyond that achieved using external beam radiotherapy alone as it has greater conformity around the prostate, sparing surrounding rectum, bladder, and penile bulb. In addition there are fewer issues with changes in prostate position during treatment delivery. Systematic review and randomised trials using both techniques as boost treatments demonstrate improved PSA control when compared to external beam radiotherapy alone [5-7].
Topics: Brachytherapy; Humans; Iodine Radioisotopes; Male; Prostate; Prostatic Neoplasms; Radiotherapy Dosage
PubMed: 34999134
DOI: 10.1016/j.radonc.2021.12.047 -
Clinical Oncology (Royal College of... Aug 2023This review aims to showcase the brachytherapy tools and technologies that have emerged during the last 10 years. Soft-tissue contrast using magnetic resonance and... (Review)
Review
This review aims to showcase the brachytherapy tools and technologies that have emerged during the last 10 years. Soft-tissue contrast using magnetic resonance and ultrasound imaging has seen enormous growth in use to plan all forms of brachytherapy. The era of image-guided brachytherapy has encouraged the development of advanced applicators and given rise to the growth of individualised 3D printing to achieve reproducible and predictable implants. These advances increase the quality of implants to better direct radiation to target volumes while sparing normal tissue. Applicator reconstruction has moved beyond manual digitising, to drag and drop of three-dimensional applicator models with embedded pre-defined source pathways, ready for auto-recognition and automation. The simplified TG-43 dose calculation formalism directly linked to reference air kerma rate of high-energy sources in the medium water remains clinically robust. Model-based dose calculation algorithms accounting for tissue heterogeneity and applicator material will advance the field of brachytherapy dosimetry to become more clinically accurate. Improved dose-optimising toolkits contribute to the real-time and adaptive planning portfolio that harmonises and expedites the entire image-guided brachytherapy process. Traditional planning strategies remain relevant to validate emerging technologies and should continue to be incorporated in practice, particularly for cervical cancer. Overall, technological developments need commissioning and validation to make the best use of the advanced features by understanding their strengths and limitations. Brachytherapy has become high-tech and modern by respecting tradition and remaining accessible to all.
Topics: Female; Humans; Brachytherapy; Uterine Cervical Neoplasms; Radiometry; Magnetic Resonance Imaging; Algorithms; Radiotherapy Planning, Computer-Assisted; Radiotherapy Dosage
PubMed: 37217434
DOI: 10.1016/j.clon.2023.05.003 -
Radiotherapy and Oncology : Journal of... Oct 2017To characterize the cosmetic outcomes and local recurrence (LR) rates of various hypofractionated radiation therapy (RT) regimens for skin basal and squamous cell... (Meta-Analysis)
Meta-Analysis
PURPOSE
To characterize the cosmetic outcomes and local recurrence (LR) rates of various hypofractionated radiation therapy (RT) regimens for skin basal and squamous cell cancers (BCCs/SCCs).
METHODS
A PICOS/PRISMA/MOOSE selection protocol was performed to identify 344 articles published between 1985-2016 evaluating patients with T1-2 N0 SCCs/BCCs treated with definitive RT. Biologically equivalent doses with α/β=3 (BEDs) were calculated. The primary endpoint was post-treatment cosmesis. Mixed effects regression models were used to estimate weighted linear relationships between BED and cosmetic outcomes.
RESULTS
A total of 21 studies were identified detailing the treatment of 9729 skin BCC/SCC patients, across seven countries, with external beam RT (n=9255) or brachytherapy (n=474). Median follow-up was 36months (range: 12-77). Median dose was 45Gy/11 fractions (interquartile range: 37.5Gy/6-55Gy/18) at 4Gy/fraction (interquartile range: 2.5-6Gy); most hypofractionated 18.75Gy/1. There was a trend to decreased "good" cosmesis with higher total dose: -3.4% "good" cosmesis/10Gy BED, p=0.01. Similarly, there was a trend to increased "fair" cosmesis with higher dose: +3.8% "fair" cosmesis/10Gy BEDp=0.006. At a BED of 100Gy, the expected rate of "good" cosmesis is 79% (95% confidence interval: 70%, 88%). Hypofractionated schedules produced similar cosmesis to conventionally fractionated schedules, at the same BED. Fewer than 8% of patients experienced "poor" cosmesis, independent of dose or fractionation regimen.
CONCLUSION
Hypofractionated RT has favorable cosmesis for patients with skin BCCs/SCCs. We recommend clinicians consider these commonly-used regimens, which all have BED of ∼100Gy: 50Gy/15 fractions, 36.75Gy/7 fractions, or 35Gy/5 fractions, as they result in "good" cosmesis in 80% of patients.
Topics: Brachytherapy; Carcinoma, Basal Cell; Carcinoma, Squamous Cell; Humans; Radiation Dose Hypofractionation; Skin Neoplasms
PubMed: 28843727
DOI: 10.1016/j.radonc.2017.08.011 -
International Journal of Radiation... Mar 2017Radiation therapy (RT) is a crucial component of cancer care, used in the treatment of over 50% of cancer patients. Patients undergoing image guided RT or brachytherapy... (Review)
Review
Radiation therapy (RT) is a crucial component of cancer care, used in the treatment of over 50% of cancer patients. Patients undergoing image guided RT or brachytherapy routinely have inert RT biomaterials implanted into their tumors. The single function of these RT biomaterials is to ensure geometric accuracy during treatment. Recent studies have proposed that the inert biomaterials could be upgraded to "smart" RT biomaterials, designed to do more than 1 function. Such smart biomaterials include next-generation fiducial markers, brachytherapy spacers, and balloon applicators, designed to respond to stimuli and perform additional desirable functions like controlled delivery of therapy-enhancing payloads directly into the tumor subvolume while minimizing normal tissue toxicities. More broadly, smart RT biomaterials may include functionalized nanoparticles that can be activated to boost RT efficacy. This work reviews the rationale for smart RT biomaterials, the state of the art in this emerging cross-disciplinary research area, challenges and opportunities for further research and development, and a purview of potential clinical applications. Applications covered include using smart RT biomaterials for boosting cancer therapy with minimal side effects, combining RT with immunotherapy or chemotherapy, reducing treatment time or health care costs, and other incipient applications.
Topics: Artificial Intelligence; Biocompatible Materials; Brachytherapy; Fiducial Markers; Humans; Nanoparticles; Radiotherapy, Image-Guided
PubMed: 28126309
DOI: 10.1016/j.ijrobp.2016.10.034 -
Brachytherapy 2022
Topics: Brachytherapy; Humans
PubMed: 35794032
DOI: 10.1016/j.brachy.2022.06.002 -
Medical Physics Oct 2015The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC),...
PURPOSE
The authors present a novel paddle-based rotating-shield brachytherapy (P-RSBT) method, whose radiation-attenuating shields are formed with a multileaf collimator (MLC), consisting of retractable paddles, to achieve intensity modulation in high-dose-rate brachytherapy.
METHODS
Five cervical cancer patients using an intrauterine tandem applicator were considered to assess the potential benefit of the P-RSBT method. The P-RSBT source used was a 50 kV electronic brachytherapy source (Xoft Axxent™). The paddles can be retracted independently to form multiple emission windows around the source for radiation delivery. The MLC was assumed to be rotatable. P-RSBT treatment plans were generated using the asymmetric dose-volume optimization with smoothness control method [Liu et al., Med. Phys. 41(11), 111709 (11pp.) (2014)] with a delivery time constraint, different paddle sizes, and different rotation strides. The number of treatment fractions (fx) was assumed to be five. As brachytherapy is delivered as a boost for cervical cancer, the dose distribution for each case includes the dose from external beam radiotherapy as well, which is 45 Gy in 25 fx. The high-risk clinical target volume (HR-CTV) doses were escalated until the minimum dose to the hottest 2 cm(3) (D(2cm(3)) of either the rectum, sigmoid colon, or bladder reached their tolerance doses of 75, 75, and 90 Gy3, respectively, expressed as equivalent doses in 2 Gy fractions (EQD2 with α/β = 3 Gy).
RESULTS
P-RSBT outperformed the two other RSBT delivery techniques, single-shield RSBT (S-RSBT) and dynamic-shield RSBT (D-RSBT), with a properly selected paddle size. If the paddle size was angled at 60°, the average D90 increases for the delivery plans by P-RSBT on the five cases, compared to S-RSBT, were 2.2, 8.3, 12.6, 11.9, and 9.1 Gy10, respectively, with delivery times of 10, 15, 20, 25, and 30 min/fx. The increases in HR-CTV D90, compared to D-RSBT, were 16.6, 12.9, 7.2, 3.7, and 1.7 Gy10, respectively. P-RSBT HR-CTV D90-values were insensitive to the paddle size for paddles angled at less than 60°. Increasing the paddle angle from 5° to 60° resulted in only a 0.6 Gy10 decrease in HR-CTV D90 on average for five cases when the delivery times were set to 15 min/fx. The HR-CTV D90 decreased to 2.5 and 11.9 Gy10 with paddle angles of 90° and 120°, respectively.
CONCLUSIONS
P-RSBT produces treatment plans that are dosimetrically and temporally superior to those of S-RSBT and D-RSBT, although P-RSBT systems may be more mechanically challenging to develop than S-RSBT or D-RSBT. A P-RSBT implementation with 4-6 shield paddles would be sufficient to outperform S-RSBT and D-RSBT if delivery times are constrained to less than 15 min/fx.
Topics: Brachytherapy; Humans; Neoplasms; Organs at Risk; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Rotation
PubMed: 26429274
DOI: 10.1118/1.4930807 -
The British Journal of Radiology Sep 2014Dosimetric audit is required for the improvement of patient safety in radiotherapy and to aid optimization of treatment. The reassurance that treatment is being... (Review)
Review
Dosimetric audit is required for the improvement of patient safety in radiotherapy and to aid optimization of treatment. The reassurance that treatment is being delivered in line with accepted standards, that delivered doses are as prescribed and that quality improvement is enabled is as essential for brachytherapy as it is for the more commonly audited external beam radiotherapy. Dose measurement in brachytherapy is challenging owing to steep dose gradients and small scales, especially in the context of an audit. Several different approaches have been taken for audit measurement to date: thimble and well-type ionization chambers, thermoluminescent detectors, optically stimulated luminescence detectors, radiochromic film and alanine. In this work, we review all of the dosimetric brachytherapy audits that have been conducted in recent years, look at current audits in progress and propose required directions for brachytherapy dosimetric audit in the future. The concern over accurate source strength measurement may be essentially resolved with modern equipment and calibration methods, but brachytherapy is a rapidly developing field and dosimetric audit must keep pace.
Topics: Brachytherapy; Calibration; Humans; Medical Audit; Radiometry; Radiotherapy Dosage; Thermoluminescent Dosimetry
PubMed: 24807068
DOI: 10.1259/bjr.20140105 -
The British Journal of Radiology Jul 2014Inoperable endometrial cancer may be treated with curative aim using radical radiotherapy alone. The radiation techniques are external beam radiotherapy (EBRT) alone,... (Review)
Review
Inoperable endometrial cancer may be treated with curative aim using radical radiotherapy alone. The radiation techniques are external beam radiotherapy (EBRT) alone, EBRT plus brachytherapy and brachytherapy alone. Recently, high-dose-rate brachytherapy has been used instead of low-dose-rate brachytherapy. Image-guided brachytherapy enables sufficient coverage of tumour and reduction of dose to the organs at risk, thus increasing the therapeutic ratio of treatment. Local control rates with three-dimensional brachytherapy appear better than with conventional techniques (about 90-100% and 70-90%, respectively).
Topics: Brachytherapy; Endometrial Neoplasms; Female; Humans; Magnetic Resonance Imaging; Radiotherapy Dosage; Radiotherapy, Image-Guided
PubMed: 24807067
DOI: 10.1259/bjr.20140018