The Impact of High-Dose-Rate Brachytherapy: Measuring Clinical Outcomes in the Primary Treatment of Cervical Cancer

Evaluating dose distributions of high dose rate 60Co brachytherapy in an asymmetric tumor: A comparison of different designs of vaginal cylindrical applicators

The aim of this study is to evaluate organ-at-risk (OAR) doses obtained from different designs of intracavitary cylinder applicators during high-dose-rate (HDR) brachytherapy of an asymmetric vaginal tumor. Dose distributions around five cylinder applicators were obtained using the Geant4 toolkit. Three of these applicators are commercially available: single-channel, multi-channel, and shielded. Additionally, two proposed sub-configurations were evaluated: (I) a combination of the multichannel applicator with a central shield and (II) a dynamically modulated cylinder (DMC). The dose distributions of the proposed applicators were compared to those of the single-channel cylinder applicator. The results showed that using a cylindrical applicator with a higher degree of freedom in plan optimization can improve OAR, sparing up to 60% for the rectum and 20% for the bladder. In conclusion, this work suggests using a new design of a cylindrical applicator to enhance the therapeutic ratio of brachytherapy for asymmetric and irregularly shaped vaginal tumors.

GammaTile: Comprehensive Review of a Novel Radioactive Intraoperative Seed-Loading Device for the Treatment of Brain Tumors

GammaTile is a Food and Drug Administration (FDA)-licensed device consisting of four cesium-131 (Cs-131) radiation-emitting seeds in the collagen tile about the postage stamp size. The tiles are utilized to line the brain cavity immediately after tumor resection. GammaTile therapy is a surgically targeted radiation therapy (STaRT) that helps provide instant, dose-intense treatment after the completion of resection. The objective of this study is to explore the safety and efficacy of GammaTile surgically targeted radiation therapy for brain tumors. This study also reviews the differences between GammaTile surgically targeted radiation therapy (STaRT) and other traditional treatment options for brain tumors. The electronic database searches utilized in this study include PubMed, Google Scholar, and ScienceDirect. A total of 4,150 articles were identified based on the search strategy. Out of these articles, 900 articles were retrieved. A total of 650 articles were excluded for various reasons, thus retrieving 250 citations. We applied the exclusion and inclusion criteria to these retrieved articles by screening their full text and excluding 180 articles. Therefore, 70 citations were retrieved and included in this comprehensive literature review, as outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) diagram. Based on the findings of this study, GammaTile surgically targeted radiation therapy (STaRT) is safe and effective for treating brain tumors. Similarly, the findings have also shown that the efficacy of GammaTile therapy can be enhanced by combining it with other standard-of-care treatment options/external beam radiation therapy (EBRT). Also, the results show that patients diagnosed with recurrent glioblastoma (GBM) exhibit poor median overall survival because of the possibility of the tumor returning. Therefore, combining STaRT with other standard-of-care treatment options/EBRT can improve the patient's overall survival (OS). GammaTile therapy enhances access to care, guarantees 100% compliance, and eliminates patients' need to travel regularly to hospitals for radiation treatments. Its implementation requires collaboration from various specialties, such as radiation oncology, medical physics, and neurosurgery.

Comparative Analysis of 60Co and 192Ir Sources in High Dose Rate Brachytherapy for Cervical Cancer

High-dose-rate (HDR) brachytherapy (BT) is an essential treatment for cervical cancer, one of the most prevalent gynecological malignant tumors. In HDR BT, high radiation doses can be delivered to the tumor target with the minimum radiation doses to organs at risk. Despite the wide use of the small HDR 192Ir source, as the technique has improved, the HDR 60Co source, which has the same miniaturized geometry, has also been produced and put into clinical practice. Compared with 192Ir (74 days), 60Co has a longer half-life (5.3 years), which gives it a great economic advantage for developing nations. The aim of the study was to compare 60Co and 192Ir sources for HDR BT in terms of both dosimetry and clinical treatment. The results of reports published on the use of HDR BT for cervical cancer over the past few years as well as our own research show that this treatment is safe and it is feasible to use 60Co as an alternative source.

Dose to pelvic lymph nodes during brachytherapy of locally advanced cervical cancer with 60Co HDR source

PURPOSE

This study investigated the correlation between the prescription dose and dose to the Manchester and International Commission on Radiation Units and Measurements-report 38 (ICRU-38) lymphatic trapezoid points during high-dose-rate (HDR) brachytherapy of locally advanced cervical cancer with (Cobalt-60) 60Co .

METHODS AND MATERIALS

A retrospective study was designed for; patients with locally advanced cervical cancer, treated by external beam radiotherapy and concurrent weekly Cisplatin-based chemotherapy, had no extended parametrial invasion and was treated by tandem-ovoid set, from 2017 to 2020. Groupe Européen de Curiethérapie-European Society for Radiotherapy and Oncology (GEC-ESTRO) based target's volume, ICRU-89 revised version of Manchester points A and B, and ICRU-38 lymph node surrogate points were determined, and their dose was recorded. Paired sample t-test, linear regression analysis, and Pearson correlation analyses were done considering a statistical significance level of 0.05 and using IBM SPSS statistics (Version 23, IBM Crop.).

RESULTS

Seventy-four brachytherapy cases were included. A positive and strong correlation was observed between D₉₀ of clinical target volume (CTV_HR) and points A and B dose for CTV_HR〈 15 cc and 〉 35 cc. Strong and significant (p < 0.05) correlations were achieved between pelvic wall points dose and D₉₀ and D₁₀₀ of the obturator and between D₅₀ and hot points of internal iliac lymph nodes. A strong correlation was obtained between D₅₀ and D₉₀ of external iliac lymph nodes and their ICRU points.

CONCLUSIONS

Strong correlations were obtained between dose to the pelvic lymphatic chains and their historical ICRU-38 surrogate points during HDR brachytherapy of locally advanced cervical cancer patients with 60Co tandem-ovoid applicator sets. The correlation strength between point A and prescription dose highly depends on the CTV_HR volume.

High dose rate192Ir versus high dose rate60Co brachytherapy: an overview of systematic reviews of clinical responses of gynecological cancers from 1984 to 2020

The Purpose. Radioisotope of192Iradium (192Ir) has a half-life (74 days) and is not easily accessible in developing countries. As a result, by the time source shipment clearance and the customs paperwork are completed, a large proportion of useful activity had already been decayed away. In fact,60Cobalt (60Co) remote afterloading systems are commercially available by many venders. As a result, it may well become an alternative source to192Ir and conform many of these challenges. The aim of this study is that to report clinical responses of different types of gynaecological cancers treated with high dose rate (HDR)192Ir and HDR60Co brachytherapy in order to check whether HDR60Co could be used as an alternative brachytherapy, source to HDR192Ir.Materials and Methods. A retrospective study of clinical responses of different types of gynaecological cancers, staged from I to IV according to recommendations of International Federation of Gynaecology and Obstetrics (FIGO), treated by brachytherapy alone, radiotherapy alone (combined brachytherapy and radiotherapy) and combined radiotherapy and chemotherapy (brachytherapy, radiotherapy and chemotherapy) between 1984 and December 2020 was conducted. The patients were treated with external beam radiotherapy 45-51 Gy boosted with HDR192Ir and HDR60Co afterloading brachytherapy of 18-30 Gy to point A.The results. The study scrutinized the data of 11086 patients with different types of gynaecological cancers. Most of the patients, 70 percent of them, were diagnosed with gynaecological cancers in stages II and III. For patients treated with192Ir brachytherapy source 5-years overall survival rate (OS), local control, 2-years, 5-years and 10-years disease free survival (DFS), complications of gastro-intestine (GI) and complications of genito-urinary (GU) were 63.5%, 92%, 72.6%, 64.07%, 43.75%, 3.9% and 5.92%, but for those treated with60Co they were 57.7%, 86.63%, 82.5%, 53.35%, 43.75%, 4.8% and 3.7%, respectively.Conclusions.The use of HDR60Co brachytherapy has the capacity to produce overall survival rate and disease control in patients with carcinoma of the gynaecology comparable to that reported for HDR192Ir brachytherapy. Currently, the toxicity and damage of the normal tissues and radiation-related second cancers are of a similar incidence to that of standard HDR192Ir brachytherapy. Source exchange frequency is not a serious concern because it requires less frequency of replacement, and commissioning can be accomplished within years; hence, replacing HDR192Ir with HDR60Co brachytherapy achieves significant cost saving. Therefore, we recommend that60Co source ought to be the first choice for low resource radiotherapy setting as it offers economic advantages over192Ir and have comparable clinical outcomes to that of192Ir source.