-
Radiotherapy and Oncology : Journal of... Oct 2022The aim of this publication is the assessment of the existing guidelines for non-melanoma skin cancer (NMSC) superficial brachytherapy (BT) and make a critical review... (Review)
Review
H&N and Skin (HNS) GEC-ESTRO Working Group critical review of recommendations regarding prescription depth, bolus thickness and maximum dose in skin superficial brachytherapy with flaps and customized moulds.
The aim of this publication is the assessment of the existing guidelines for non-melanoma skin cancer (NMSC) superficial brachytherapy (BT) and make a critical review based on the existing literature about the maximum dose prescription depth, bolus thickness and maximum skin surface dose (D) of the published clinical practice. A systematic review of NMSC superficial BT published articles was carried out by the GEC-ESTRO Head & Neck and Skin (HNS) Working Group (WG). 10 members and 2 external reviewers compared the published clinical procedures with the recommendations in the current guidelines and examined the grade of evidence. Our review verified that there is a large variation among centres with regards to clinical practice in superficial BT and identified studies where published parameters such as maximum dose prescription depth, bolus thickness and D exceed the constraints recommended in the guidelines, while showing excellent results in terms of local control, toxicity and cosmesis. This review confirmed that current recommendations on skin superficial BT do not include published experience on tumours treated with superficial BT that require dose prescription depth beyond the recommended 5 mm under the skin surface and that the existing literature does not provide sufficient evidence to relate dosimetry of superficial BT to patient reported outcome measures. The GEC-ESTRO HNS WG considers acceptable to prescribe superficial BT dose at a depth above 5 mm beyond the skin surface, and modify the bolus thickness to optimize the treatment plan and adjust the acceptable maximum dose on the skin surface, all pending clinical situation.
Topics: Humans; Brachytherapy; Skin Neoplasms; Radiometry; Prescriptions; Radiotherapy Dosage
PubMed: 36030932
DOI: 10.1016/j.radonc.2022.08.022 -
Radiotherapy and Oncology : Journal of... Oct 2022Recently, a number of clinical studies have explored links between possible Relative Biological Effectiveness (RBE) elevations and patient toxicities and/or image... (Review)
Review
Recently, a number of clinical studies have explored links between possible Relative Biological Effectiveness (RBE) elevations and patient toxicities and/or image changes following proton therapy. Our objective was to perform a systematic review of such studies. We applied a "Problem [RBE], Intervention [Protons], Population [Patients], Outcome [Side effect]" search strategy to the PubMed database. From our search, we retrieved studies which: (a) performed novel voxel-wise analyses of patient effects versus physical dose and LET (n = 13), and (b) compared image changes between proton and photon cohorts with regard to proton RBE (n = 9). For each retrieved study, we extracted data regarding: primary tumour type; size of patient cohort; type of image change studied; image-registration method (deformable or rigid); LET calculation method, and statistical methodology. We compared and contrasted their methods in order to discuss the weight of clinical evidence for variable proton RBE. We concluded that clinical evidence for variable proton RBE remains statistically weak at present. Our principal recommendation is that proton centres and clinical trial teams collaborate to standardize follow-up protocols and statistical analysis methods, so that larger patient cohorts can ultimately be considered for RBE analyses.
Topics: Humans; Relative Biological Effectiveness; Proton Therapy; Protons; Linear Energy Transfer; Radiotherapy Planning, Computer-Assisted
PubMed: 35988776
DOI: 10.1016/j.radonc.2022.08.014 -
Current Medical Imaging 2023For almost three decades, computed tomography (CT) has been extensively used in medical diagnosis, which led researchers to conduct linking of CT dose exposure with... (Meta-Analysis)
Meta-Analysis
BACKGROUND
For almost three decades, computed tomography (CT) has been extensively used in medical diagnosis, which led researchers to conduct linking of CT dose exposure with image quality.
METHODS
In this study, a systematic review and a meta-analysis study were conducted on CT phantom for resolution study especially based on the low contrast detectability (LCD). Furthermore, the association between the CT parameter such as tube voltage and the type of reconstruction algorithm, the amount of phantom scanning affecting the image quality and the exposure dose were also investigated in this study. We utilize PubMed, ScienceDirect, Google Scholar and Scopus databases to search related published articles from the year 2011 until 2020. The notable keywords comprise "computed tomography", "CT phantom", and "low contrast detectability". Of 52 articles, 20 articles are within the inclusion criteria in this systematic review.
RESULTS
The dichotomous outcomes were chosen to represent the results in terms of risk ratio as per meta-analysis study. Notably, the noise in iterative reconstruction (IR) reduced by 24%, 33% and 36% with the use of smooth, medium and sharp filters, respectively. Furthermore, adaptive iterative dose reduction (AIDR 3D) improved image quality and the visibility of smaller less dense objects compared to filtered back-projection. Most of the researchers used 120 kVp tube voltage to scan phantom for quality assurance study.
CONCLUSION
Hence, optimizing primary factors such as tube potential reduces the dose exposure significantly, and the optimized IR technique could substantially reduce the radiation dose while maintaining the image quality.
Topics: Humans; Radiation Dosage; Tomography, X-Ray Computed; Algorithms; Phantoms, Imaging; Radiographic Image Interpretation, Computer-Assisted
PubMed: 35975862
DOI: 10.2174/1573405618666220816160544 -
Physica Medica : PM : An International... Sep 2022The optimal radiotherapy technique for patients requiring both breasts or chest walls simultaneous irradiation with or without regional nodal irradiation is currently... (Review)
Review
The optimal radiotherapy technique for patients requiring both breasts or chest walls simultaneous irradiation with or without regional nodal irradiation is currently under investigation. In the last decade several publications present case reports and case series of patients treated with adjuvant radiotherapy in both breasts or chest walls for synchronous bilateral breast cancer (SBBC) with modern radiotherapy techniques. This article presents a systematic review of relevant literature as well as a case report of a SBBC patient who received bilateral chest wall radiotherapy with regional nodal irradiation at our institution with Truebeam - Edge Linear Accelerator. Solid evidence is provided that the practice of avoiding adjuvant radiotherapy in SBBC out of fear of toxicity with older radiotherapy techniques is outdated. Modern techniques can safely and effectively deliver treatment to patients requiring both sides irradiation and even in mastectomy patients in need of regional nodal irradiation.
Topics: Breast Neoplasms; Female; Humans; Mastectomy; Radiotherapy Dosage; Radiotherapy, Intensity-Modulated; Thoracic Wall
PubMed: 35961182
DOI: 10.1016/j.ejmp.2022.07.005 -
Brachytherapy 2022Despite advancements in the early detection of esophageal cancer, optimal radiotherapy methods for treatment of early disease have not yet been determined. Moreover, the...
PURPOSE
Despite advancements in the early detection of esophageal cancer, optimal radiotherapy methods for treatment of early disease have not yet been determined. Moreover, the benefit of intraluminal brachytherapy on local control or survival remains controversial. We performed a systematic review to establish the role of brachytherapy as boost therapy in stage I esophageal squamous cell carcinoma, and to evaluate associated survival outcomes.
METHODS AND MATERIALS
A systematic search of three bibliographic databases from January 1950 to January 2019 was conducted. All studies investigating brachytherapy for curative intent were included and palliative treatment was excluded. Primary outcomes included overall survival and disease-free survival (DFS). Secondary outcomes included loco-regional control (LRC) and toxicity grades and/or complications. Two reviewers independently abstracted data and evaluated study quality using grading of recommendations assessment, development, and evaluation, pooled results were presented through risk ratios.
RESULTS
A total of 12 retrospective studies met inclusion criteria. The overall quality of evidence yielded a Grade 1C rating (strong recommendation, low quality evidence). Of 525 included patients, 325 patients received both external beam radiation (EBRT), and brachytherapy, 132 underwent EBRT only, and 68 received brachytherapy with and/or without chemoradiation. For patient group treated with EBRT and brachytherapy, 5-year mortality, DFS and LRC were: 43% (27-59%), 63% (49-76%) and 72% (63-80%) respectively. Rates of complications reported included 82.1% Grade 1 esophagitis for a combined external beam radiation and brachytherapy cohort, 12.3% ulcerations, and 3.3% fistulae.
CONCLUSIONS
Brachytherapy as a combined modality is encouraging, given its relative safety and effectiveness. Further prospective analysis using higher quality evidence is warranted to evaluate oncologic outcomes and survival advantage.
Topics: Humans; Brachytherapy; Esophageal Neoplasms; Retrospective Studies; Esophageal Squamous Cell Carcinoma; Radiotherapy Dosage
PubMed: 35941072
DOI: 10.1016/j.brachy.2022.05.007 -
Medical Physics Sep 2022The use of deep learning (DL) to improve cone-beam CT (CBCT) image quality has gained popularity as computational resources and algorithmic sophistication have advanced... (Review)
Review
The use of deep learning (DL) to improve cone-beam CT (CBCT) image quality has gained popularity as computational resources and algorithmic sophistication have advanced in tandem. CBCT imaging has the potential to facilitate online adaptive radiation therapy (ART) by utilizing up-to-date patient anatomy to modify treatment parameters before irradiation. Poor CBCT image quality has been an impediment to realizing ART due to the increased scatter conditions inherent to cone-beam acquisitions. Given the recent interest in DL applications in radiation oncology, and specifically DL for CBCT correction, we provide a systematic theoretical and literature review for future stakeholders. The review encompasses DL approaches for synthetic CT generation, as well as projection domain methods employed in the CBCT correction literature. We review trends pertaining to publications from January 2018 to April 2022 and condense their major findings-with emphasis on study design and DL techniques. Clinically relevant endpoints relating to image quality and dosimetric accuracy are summarized, highlighting gaps in the literature. Finally, we make recommendations for both clinicians and DL practitioners based on literature trends and the current DL state-of-the-art methods utilized in radiation oncology.
Topics: Cone-Beam Computed Tomography; Deep Learning; Humans; Image Processing, Computer-Assisted; Phantoms, Imaging; Radiometry; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted
PubMed: 35789489
DOI: 10.1002/mp.15840 -
Dermatologic Therapy Sep 2022Nonmelanoma skin cancers (NMSCs) are the most common malignancies worldwide. Millions of new cases every year present challenge to healthcare systems. Recent years... (Review)
Review
Nonmelanoma skin cancers (NMSCs) are the most common malignancies worldwide. Millions of new cases every year present challenge to healthcare systems. Recent years brought numerous new data concerning high dose rate (HDR) brachytherapy (BT) as treatment option for NMSCs. International guidelines do not recognize BT as a method of choice given lack of randomized trials, however many prospective and retrospective studies show promising results. Aim of the study was to present the efficacy of HDR BT, with analysis of its safety and adverse effects based on review of the English published medical full-text papers. Literature review of 13 articles published between 1999 and 2021 was performed. Pubmed and Google Scholar databases were searched on October 2021 using keywords: ([Basal cell carcinoma] OR [squamous cell carcinoma] OR [non-melanoma skin cancer]) AND (HDR brachytherapy). Fourteen full-text English articles with follow up over 1 year and study group over 50 patients were included into analysis. In analyzed material, 2403 patients received HDR BT. Local control varied between 71% and 99%.Dominant reported cosmetic effect was good or very good. Results were cross-referenced with recent meta-analyses comparing BT to surgical excision, Mohs microsurgery and external beam radiotherapy. Radiodermitis is the main adverse effect of radiation treatment during and after radiotherapy. HDR BT emerges as potentially noninferior treatment method providing very good reported cosmetic outcomes.
Topics: Brachytherapy; Carcinoma, Basal Cell; Humans; Prospective Studies; Radiotherapy Dosage; Retrospective Studies; Skin Neoplasms
PubMed: 35770511
DOI: 10.1111/dth.15675 -
Current Oncology (Toronto, Ont.) May 2022Selective internal radiation therapy (SIRT) with yttrium-90 (Y)-loaded microspheres is increasingly used for the treatment of Intrahepatic Cholangiocarcinoma (ICC).... (Review)
Review
Selective internal radiation therapy (SIRT) with yttrium-90 (Y)-loaded microspheres is increasingly used for the treatment of Intrahepatic Cholangiocarcinoma (ICC). Dosimetry verifications post-treatment are required for a valid assessment of any dose-response relationship. We performed a systematic review of the literature to determine how often clinics conducted post-treatment dosimetry verification to measure the actual radiation doses delivered to the tumor and to the normal liver in patients who underwent SIRT for ICC, and also to explore the corresponding dose-response relationship. We also investigated other factors that potentially affect treatment outcomes, including the type of microspheres used and concomitant chemotherapy. Out of the final 47 studies that entered our study, only four papers included post-treatment dosimetry studies after SIRT to quantitatively assess the radiation doses delivered. No study showed that one microsphere type provided a benefit over another, one study demonstrated better imaging-based response rates associated with the use of glass-based TheraSpheres, and two studies found similar toxicity profiles for different types of microspheres. Gemcitabine and cisplatin were the most common chemotherapeutic drugs for concomitant administration with SIRT. Future studies of SIRT for ICC should include dosimetry to optimize treatment planning and post-treatment radiation dosage measurements in order to reliably predict patient responses and liver toxicity.
Topics: Humans; Bile Duct Neoplasms; Bile Ducts, Intrahepatic; Chemoradiotherapy; Cholangiocarcinoma; Yttrium Radioisotopes
PubMed: 35735415
DOI: 10.3390/curroncol29060306 -
Expert Review of Cardiovascular Therapy Jul 2022The evolution of endovascular surgery over the past 30 years has made it possible to treat increasingly complex vascular pathologies with an endovascular method....
INTRODUCTION
The evolution of endovascular surgery over the past 30 years has made it possible to treat increasingly complex vascular pathologies with an endovascular method. Although this generally speeds up the patient's recovery, the risks of health problems caused by long-term exposure to radioactive radiation increase. This warrants the demand for radiation-reducing tools to reduce radiation exposure during these procedures.
AREAS COVERED
For this systematic review Pubmed, Embase and Cochrane library databases were searched on 28 December 2021 to provide an overview of tools that are currently used or have the potential to contribute to reducing radiation exposure during endovascular aortic procedures. In addition, an overview is presented of radiation characteristics of clinical studies comparing a (potential) radiation-reducing device with conventional fluoroscopy use.
EXPERT OPINION
Radiation-reducing instruments such as fiber optic shape sensing or electromagnetic tracking devices offer the possibility to further reduce or even eliminate the use of radiation during endovascular procedures. In an era of increasing endovascular interventional complexity and awareness of the health risks of long-term radiation exposure, the use of these technologies could have a major impact on an ongoing challenge to move toward radiation-free endovascular surgery.
Topics: Aorta; Endovascular Procedures; Fluoroscopy; Humans; Radiation Dosage; Radiation Exposure
PubMed: 35726665
DOI: 10.1080/14779072.2022.2092096 -
Radiotherapy and Oncology : Journal of... Aug 2022For radiotherapy of thoracic and abdominal tumors safety margins are applied to address geometrical uncertainties caused by e.g. set-up errors, organ motion and... (Review)
Review
For radiotherapy of thoracic and abdominal tumors safety margins are applied to address geometrical uncertainties caused by e.g. set-up errors, organ motion and delineation variability. For pediatric patients no standardized margins are defined. Moreover, studies on these geometrical uncertainties are relatively scarce. Therefore, this systematic review presents an overview of organ motion, applied margin sizes and delineation variability in patients <18 years. A search from January 2000 to March 2021 in Medline, Embase, Web of Science, ClinicalTrials.gov and the International Trials Registry Platform resulted in the inclusion of 117 studies reporting on organ motion, margin sizes and/or delineation variability. Studies were heterogeneous concerning age, tumor types, the use of general anesthesia, imaging modalities; image guidance techniques were reported in 39% of the studies. Inter- and intrafractional motion as reported for different organs was largest in cranio-caudal direction and ranged from -9.1 to 10.0 mm and -4.4 to 19.5 mm, respectively. Motion quantification methodologies differed between studies regarding measures of displacement and definitions of motion direction. Reported CTV-PTV margins varied from 3 to 20 mm for both thoracic and abdominal targets, and for spinal and pelvic from 3to 15 mm and 3 to 10 mm, respectively. Studies reported wide variation in interobserver variability of target volume delineation, which may affect dose distributions to both target volumes and organs at risk. Results of this review indicate possible reduction of margin sizes for children, however, wide variation in organ motion and delineation variability caused by differences in methodologies and outcomes hamper the use of standardized margins.
Topics: Child; Dose Fractionation, Radiation; Humans; Organ Motion; Radiotherapy Dosage; Radiotherapy Planning, Computer-Assisted; Radiotherapy, Image-Guided
PubMed: 35640771
DOI: 10.1016/j.radonc.2022.05.021