Clinical implementation of a novel applicator in high-dose-rate brachytherapy treatment of esophageal cancer

A Secure Artificial Intelligence-Enabled Critical Sars Crisis Management Using Random Sigmoidal Artificial Neural Networks

Since December 2019, the pandemic COVID-19 has been connected to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Early identification and diagnosis are essential goals for health practitioners because early symptoms correlate with those of other common illnesses including the common cold and flu. RT-PCR is frequently used to identify SARS-CoV-2 viral infection. Although this procedure can take up to 2 days to complete and sequential monitoring may be essential to figure out the potential of false-negative findings, RT-PCR test kits are apparently in low availability, highlighting the urgent need for more efficient methods of diagnosing COVID-19 patients. Artificial intelligence (AI)-based healthcare models are more effective at diagnosing and controlling large groups of people. Hence, this paper proposes a novel AI-enabled SARS detection framework. Here, the input CT images are collected and preprocessed using a block-matching filter and histogram equalization (HE). Segmentation is performed using Compact Entropy Rate Superpixel (CERS) technique. Features of segmented output are extracted using Histogram of Gradient (HOG). Feature selection is done using Principal Component Analysis (PCA). The suggested Random Sigmoidal Artificial Neural Networks (RS-ANN) based classification approach effectively diagnoses the existence of the disease. The performance of the suggested Artificial intelligence model is analyzed and related to existing approaches. The suggested AI system may help identify COVID-19 patients more quickly than conventional approaches.

Time-resolved QA and brachytherapy applicator commissioning: Towards the clinical implementation

PURPOSE

Brachytherapy has a busy workflow relying on manual steps to ensure accurate delivery of the treatment. Systematic treatment errors have been reported due to faulty equipment, inadequate quality assurance (QA) and applicator commissioning methods. This study describes the use of a novel method, the Iridium Imaging System for QA (IrIS - QA), to automate and improve the applicator commissioning for HDR ¹⁹²Ir brachytherapy.

METHODS AND MATERIALS

A 3D printed holder attached to an Imaging Panel (IP) has been developed to: (1) acquire a high-definition projection of the applicator using the gamma rays of the ¹⁹²Ir source for imaging; (2) Track the source within the applicator verifying in a time-resolved manner the dwell positions and dwell times with a high resolution. Results obtained for two applicator models are described in this manuscript.

RESULTS

IrIS-QA is capable of measuring the dwell times with an accuracy better than 0.1 s and interdwell distances with submillimetre precision. The applicators tested in the study showed good agreement between planned and delivered dwell times and positions, with mean and maximum dwell position deviations below 0.5 mm and 1.3 mm, respectively. Dwell time measurements showed agreement superior to 0.05 s except for the first dwell position for which up to 0.15 s differences were observed.

CONCLUSIONS

IrIS-QA is a compact system that includes many features necessary to improve the accuracy and efficiency of applicator commissioning and daily QA. No commercial system exists with similar capabilities. IrIS-QA is intended to replace current clinical procedures using film dosimetry.

Dose reduction in HDR brachytherapy of esophageal cancer using gold and gold alloy plaques: a Monte Carlo study

In this work, the use of gold and gold alloy plaques is proposed for the first time, to reduce the dose to healthy organs in brachytherapy with Ir-192 sources. For dose simulations in tumour and healthy tissue, the MCNPX Monte Carlo code was used. The radiation source implemented in those simulations was benchmarked with well-known TG-43 criteria of dose rate constant, air-kerma strength, radial dose function, and 2D anisotropy function. For various arrangements of iridium sources and plaques of gold and gold alloy of various thicknesses, the dose distributions in an esophagus tumour and in surrounding healthy organs were simulated. The results showed that while the dose to the tumour is not much affected by the presence of gold plaques with a thickness of 3.5 mm in an optimized ¹⁹²Ir sources' configuration, a relative reduction in average organ dose of 64%, 65%, 73%, 67%, and 35% was observed, for esophagus, thyroid, heart, stomach, and liver, respectively. Moreover, it was found that a gold plaque leads to smaller doses to healthy organs than a gold alloy plaque. It is concluded that gold plaques can be used to improve the treatment of esophageal cancer by HDR brachytherapy and to protect surrounding non-target organs.

Brachytherapy for Oesophageal Carcinoma: A Comprehensive Review of Literature and Techniques

Introduction:

Oesophageal carcinoma is one of the fatal cancers mainly because of its rapid spread and poor prognosis. Treatment modalities involves a multimodality approach, including surgery, radiation therapy and chemotherapy. Radiation therapy includes brachytherapy in the form of intraluminal radiation therapy. Brachytherapy permits delivery of high tumouricidal doses to superficial cancerous growth of the oesophagus while delivering much lower doses to the surrounding tissue. It is mostly given in combination with external beam radiation in patients with poor performance scores not likely to tolerate an aggressive chemoradiation regimen or as a boost to concurrent chemoradiotherapy. It is very effective in terms of local tumour control as well as in relieving symptoms in advanced/recurrent disease. Intraoperative brachytherapy and seed brachytherapy have also been tried to address the nodal disease.

Methods:

We undertook a review of the available literature and techniques developed in the past three decades to emphasise the role of brachytherapy in curative or palliative settings in the treatment of oesophageal carcinoma.

Conclusion:

Oesophageal brachytherapy will remain a tangible treatment of oesophageal cancer, although it is less commonly used due to high expertise requirement, lack of established evidence, risk of life-threatening complications and lack of interest in brachytherapy. It offers quick and useful palliation for a prolonged period, along with good quality of life and superior dosimetry. Use of novel applicators may allow dose escalation and lower toxicity. Seed brachytherapy is also emerging as a promising option in nodal recurrences.

The Overexpression of Kinesin Superfamily Protein 2A (KIF2A) was Associated with the Proliferation and Prognosis of Esophageal Squamous Cell Carcinoma

Aim

Kinesin family member 2A (KIF2A) is a member of the kinesin-13 superfamily protein. KIF2A played a role in the development of many tumors. However, the role of KIF2A in esophageal squamous cell carcinoma (ESCC) remains unclear. In this study, we aimed to investigate the role of KIF2A in ESCC.

Methods

We used bioinformatics analysis to study the expression levels and prognosis of KIF2A in ESCC and normal tissues. We also used our own samples to verify the results by immunohistochemistry. Then, the biological functions of KIF2A in ESCC was studied by cell experiments and animal experiments.

Results

Both the TCGA database and our samples showed that KIF2A was relatively highly expressed in ESCC tissues and was significantly associated with disease-free survival (P =0.037) in TCGA database. Colony formation assay, CCK8 and Western blotting results showed that knockdown of KIF2A can significantly reduce colony forming ability and proliferation ability. The results of animal experiments showed that knocking down KIF2A can significantly reduce the tumor volume of mice.

Conclusion

KIF2A might be used as a prognostic factor for ESCC, and knockdown of KIF2A could inhibit ESCC proliferation in vitro and in vivo, respectively. KIF2A could serve as a potential prognostic biomarker and therapeutic target for future ESCC.

A novel system for commissioning brachytherapy applicators: example of a ring applicator

A novel system was developed to improve commissioning and quality assurance of brachytherapy applicators used in high dose rate (HDR). It employs an imaging panel to create reference images and to measure dwell times and dwell positions. As an example: two ring applicators of the same model were evaluated. An applicator was placed on the surface of an imaging panel and a HDR ¹⁹²Ir source was positioned in an imaging channel above the panel to generate an image of the applicator, using the gamma photons of the brachytherapy source. The applicator projection image was overlaid with the images acquired by capturing the gamma photons emitted by the source dwelling inside the applicator. We verified 0.1, 0.2, 0.5 and 1.0 cm interdwell distances for different offsets, applicator inclinations and transfer tube curvatures. The data analysis was performed using in-house developed software capable of processing the data in real time, defining catheters and creating movies recording the irradiation procedure. One applicator showed up to 0.3 cm difference from the expected position for a specific dwell position. The problem appeared intermittently. The standard deviations of the remaining dwell positions (40 measurements) were less than 0.05 cm. The second ring applicator had a similar reproducibility with absolute coordinate differences from expected values ranging from  -0.10 up to 0.18 cm. The curvature of the transfer tube can lead to differences larger than 0.1 cm whilst the inclination of the applicator showed a negligible effect. The proposed method allows the verification of all steps of the irradiation, providing accurate information about dwell positions and dwell times. It allows the verification of small interdwell positions (⩽0.1 cm) and reduces measurement time. In addition, no additional radiation source is necessary since the HDR ¹⁹²Ir source is used to generate an image of the applicator.

PAQR3 Inhibits the Proliferation and Tumorigenesis in Esophageal Cancer Cells

Progestin and adipoQ receptor family member III (PAQR3), a member of the PAQR family, is frequently downregulated in different types of human cancer. However, its expression and functions in esophageal cancer are still unknown. This study aimed to explore the expression of PAQR3 in esophageal cancer cell lines and to investigate the role of PAQR3 in the development of esophageal cancer. Our data showed that PAQR3 is expressed in low amounts in human esophageal cancer cell lines. Overexpression of PAQR3 significantly suppressed the proliferation, migration, and invasion of esophageal cancer cells. In addition, overexpression of PAQR3 downregulated the protein expression levels of RAF1, p-MEK1, and p-ERK1/2 in esophageal cancer cells. Furthermore, overexpression of PAQR3 attenuated the tumor growth in a tumor xenograft model. In conclusion, we demonstrated that overexpression of PAQR3 suppresses cell proliferation, migration, and invasion in esophageal cancer in vitro and in vivo. Therefore, PAQR3 may act as a therapeutic target for human esophageal cancer.

High-dose-rate intraluminal brachytherapy prior to external radiochemotherapy in locally advanced esophageal cancer: preliminary results

PURPOSE

Dysphagia is a common initial presentation in locally advanced esophageal cancer and negatively impacts patient quality of life and treatment compliance. To induce fast relief of dysphagia in patients with potentially operable esophageal cancer high-dose-rate (HDR) brachytherapy was applied prior to definitive radiochemotherapy.

MATERIAL AND METHODS

In this single arm phase II clinical trial between 2013 to 2014 twenty patients with locally advanced esophageal cancer (17 squamous cell and 3 adenocarcinoma) were treated with upfront 10 Gy HDR brachytherapy, followed by 50.4 Gy external beam radiotherapy (EBRT) and concurrent chemotherapy with cisplatin/5-fluorouracil.

RESULTS

Tumor response, as measured by endoscopy and/or computed tomography scan, revealed complete remission in 16 and partial response in 4 patients (overall response rate 100%). Improvement of dysphagia was induced by brachytherapy within a few days and maintained up to the end of treatment in 80% of patients. No differences in either response rate or dysphagia resolution were found between squamous cell and adenocarcinoma histology. The grade 2 and 3 acute pancytopenia or bicytopenia reported in 4 patients, while sub-acute adverse effects with painful ulceration was seen in five patients, occurring after a median of 2 months. A perforation developed in one patient during the procedure of brachytherapy that resolved successfully with immediate surgery.

CONCLUSIONS

Brachytherapy before EBRT was a safe and effective procedure to induce rapid and durable relief from dysphagia, especially when combined with EBRT.

Safety and outcome of external beam radiation and neutron brachytherapy in elderly patients with esophageal squamous cell cancer

Purpose

The aim of this study was to retrospectively observe and analyze the long-term treatment outcomes of 191 elderly patients with esophageal squamous cell cancer (ESCC) who were treated with californium-252 (²⁵²Cf) neutron brachytherapy (NBT) in combination with external beam radiotherapy (EBRT).

Material and methods

From January 2002 to November 2012, 191 patients with ESCC underwent NBT in combination with EBRT. The total radiation dose to the reference point via NBT was 8-25 Gy-eq in two to five fractions with one fraction per week. The total dose via EBRT was 50-60 Gy, which was delivered over a period of 5 to 6 weeks with normal fractionation.

Results

The median survival time for the 191 patients was 23.6 months, and the 5-year rates for overall survival (OS) and local-regional control (LRC) were 28.7% and 54.2%, respectively. The patients’ age was a factor that was significantly associated with OS (p = 0.010), according to univariate analysis. The 5-year OS (LRC) was 37.3% (58.6%) for patients aged 70-74 years and 14.5% (47.9%) for patients aged > 74 years (p = 0.010 and p = 0.038). In multivariate analysis, age and clinical N stage were associated with OS and LRC (p = 0.011 [0.041] and p = 0.005 [0.005]). From the time of treatment completion to the development of local-regional recurrence or death, 5 (2.6%) patients experienced fistula and 15 (7.9%) experienced massive bleeding. The incidence of severe late complications was related to older age (p = 0.027), higher NBT dose/fraction (20-25 Gy/5 fractions), and higher total dose (> 66 Gy).

Conclusions

The clinical data indicated that NBT in combination with EBRT produced favorable local control and long-term survival rates for elderly patients with ESCC, and that the side effects were tolerable. Patient’s age, clinical stage N status, and radiation dose could be used to select the appropriate treatment for elderly patients.