scholarly journals Estimating the accumulative dose uncertainty for intracavitary and interstitial brachytherapy

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Binbing Wang ◽  
Weibiao Hu ◽  
Guoping Shan ◽  
Xiaoxian Xu
Keyword(s):  
Displacement Vector ◽  
Interstitial Brachytherapy ◽  
Intracavitary Brachytherapy ◽  
Reference Image ◽  
High Dose ◽  
Dice Similarity Coefficient ◽  
Normal Tissues ◽  
Significant Difference ◽  
Fractional Dose ◽  
High Doses

Abstract Background Image-guided adaptive brachytherapy shows the ability to deliver high doses to tumors while sparing normal tissues. However, interfraction dose delivery introduces uncertainties to high dose estimation, which relates to normal tissue toxicity. The purpose of this study was to investigate the high-dose regions of two applicator approaches in brachytherapy. Method For 32 cervical cancer patients, the CT images from each fraction were wrapped to a reference image, and the displacement vector field (DVF) was calculated with a hybrid intensity-based deformable registration algorithm. The fractional dose was then accumulated to calculate the position and the overlap of high dose (D2cc) during multiple fractions. Result The overall Dice similarity coefficient (DSC) of the deformation algorithm for the bladder and the rectum was (0.97 and 0.91). No significant difference was observed between the two applicators. However, the location of the intracavitary brachytherapy (ICBT) high-dose region was relatively concentrated. The overlap volume of bladder and rectum D2cc was 0.42 and 0.71, respectively, which was higher than that of interstitial brachytherapy (ISBT) (0.26 and 0.31). The cumulative dose was overestimated in ISBT cases when using the GEC-recommended method. The ratio of bladder and rectum D2cc to the GEC method was 0.99 and 1, respectively, which was higher than that of the ISBT method (0.96 and 0.94). Conclusion High-dose regions for brachytherapy based on different applicator types were different. The 3D-printed ICBT has better high-dose region consistency than freehand ISBT and hence is more predictable.

scholarly journals Comparative study to evaluate dosimetric differences in patients of locally advanced carcinoma cervix undergoing intracavitary brachytherapy under two different anaesthesia techniques: an audit from a tertiary cancer centre in India

2019 ◽  
Vol 31 (1) ◽  
Author(s):  
Divyesh Kumar ◽  
G. Y. Srinivasa ◽  
Ankita Gupta ◽  
Bhavana Rai ◽  
Arun S. Oinam ◽  
...  
Keyword(s):  
Day Care ◽  
Treatment Time ◽  
Locally Advanced ◽  
Effective Alternative ◽  
External Beam Radiation ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Carcinoma Cervix ◽  
Beam Radiation ◽  
Significant Difference

Abstract Background Carcinoma cervix is amongst the leading causes of mortality and morbidity in women population worldwide. High-dose-rate intracavitary brachytherapy (HDR-ICBT) post external beam radiation therapy (EBRT) is the standard of care in managing locally advanced stage cervical cancer patients. HDR-ICBT is generally performed under general anaesthesia (GA) in operation theatre (OT), but due to logistic reasons, sometimes, it becomes difficult to accommodate all patients under GA. Since prolonged overall treatment time (OTT) makes the results inferior, taking patients in day care setup under procedural sedation (PS) can be an effective alternative. In this audit, we tried to retrospectively analyse the dosimetric difference, if any, in patients who underwent ICBT at our centre, under either GA in OT or PS in day care. Results Thirty five patients were analysed 16/35 (45.71%) patients underwent HDR-ICBT under GA while 19/35 (54.28%) patients under PS. In both groups, a statistically significant difference was observed between the dose received by 0.1 cc as well as 2 cc of rectum (p < 0.05), while the bladder and sigmoid colon had comparable dosages. Conclusion Though our dosimetric analysis highlighted better rectal sparing in patients undergoing HDR-ICBT under GA when compared to patients under PS, PS can still be considered an effective alternative, especially in centres dealing with significant patient load. Further studies are required for firm conclusion.

Influence of changes in arterial pCO2 on cerebral blood flow and metabolism during high-dose barbiturate therapy in dogs

1981 ◽  
Vol 54 (5) ◽  
pp. 615-619 ◽  
Author(s):  
Neal F. Kassell ◽  
Patrick W. Hitchon ◽  
Mary K. Gerk ◽  
Martin D. Sokoll ◽  
Todd R. Hill
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
High Dose ◽  
Sodium Thiopental ◽  
Arterial Pco2 ◽  
Content Type ◽  
Cerebral Vasoconstriction ◽  
Significant Difference ◽  
Before And After ◽  
High Doses

✓ In 13 dogs the response of the cerebral circulation to changes in PaCO2 ranging from 20 to 60 torr was studied before and after administration of high doses of sodium thiopental. Infusion of sufficient barbiturate to produce 30- to 60-second burst suppression in the electroencephalogram was associated with a profound degree of cerebral vasoconstriction, equivalent to that produced by hypocapnia with PaCO2 = 20 torr. Furthermore, once sodium thiopental was administered, no significant difference in cerebral blood flow (CBF) or vascular resistance (CVR) was noted between PaCO2 of 30 and 20 torr. However, changes of approximately 15% in CBF and 30% in CVR were noted between PaCO2 at 40 and 20 torr. These data suggest that hyperventilation of PaCO2 of less than 30 torr may not effectively increase the degree of cerebral vasoconstriction in these circumstances.

scholarly journals Toxicity Outcome Using Bladder-Rectum Spacer Balloon Versus Vaginal Gauze Packing in Brachytherapy in Cervical Cancer.

2021 ◽  
Author(s):  
Nagarjun Ballari ◽  
Sakshi Rana ◽  
Bhavana Rai ◽  
Srinivasa Gowda ◽  
Suja Bhargavan ◽  
...  
Keyword(s):  
Cervical Cancer ◽  
Randomized Study ◽  
High Dose Rate ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Clinical Trial Registry ◽  
Gauze Packing ◽  
Dosimetric Data ◽  
Significant Difference

Abstract BACKGROUNDTo compare the clinical impact in terms of toxicity outcomes with RayshieldTM bladder rectum spacer balloon (BRSB) versus vaginal gauze packing (VGP) in patients treated with high dose rate intracavitary brachytherapy for carcinoma cervix.RESULTSFollow-up and dosimetric data of patients in whom BRSB and VGP were used in a previously reported randomized study were retrieved, 8. Out of 80 patients analysed, late toxicities assessment (according to Common Terminology Criteria for Adverse Events version 4.0 (CTCAE v4). was possible in 65 patients as 14 patients were lost to follow-up and one patient died. Grade 2 bladder toxicity was observed in 2 patients in each arm. Only 1 patient in VGP arm experienced grade 3 proctitis while none of the patient in BRSB arm had ³Grade 2 rectal toxicity. Vaginal toxicity was comparable in both the arms.CONCLUSION No significant difference was observed in bladder and rectal toxicities using the BRSB versus VGP. BRSB can be considered as an alternative to VGP in intracavitary brachytherapy for cervical cancer using tandem- ovoid applicatorsThe study was approved by the institute ethics committee and registered under Clinical Trial Registry of India (CTRI/2009/091/000840).

scholarly journals The Preliminary Results of 3-Dimensional Printed Individual Template Assisted 192Ir High-Dose Rate Interstitial Brachytherapy for Central Recurrent Gynecologic Cancer

2020 ◽  
Vol 19 ◽  
pp. 153303382097160
Author(s):  
Ping Jiang ◽  
Ang Qu ◽  
Shuhua Wei ◽  
Haitao Sun ◽  
Xile Zhang ◽  
...  
Keyword(s):  
Dose Rate ◽  
Gynecologic Cancer ◽  
High Dose Rate ◽  
Interstitial Brachytherapy ◽  
High Dose ◽  
Type I ◽  
Type Ii ◽  
3 Dimensional ◽  
Significant Difference ◽  
Recurrent Gynecologic Cancer

Objective: To evaluate the feasibility and safety of high dose rate interstitial brachytherapy (HDR-IB) assisted with 3-dimensional printing individual template (3D-PIT) for central pelvic recurrent gynecologic cancer (CR-GYN). Methods: Totally 32 patients diagnosed with CR-GYN received iridium-192(192Ir) HDR-IB assisted with 3D-PIT that was classified in 2 types(Type I: transvaginal template/ applicator, and Type II: transvaginal combined transperineal template). The prescribed dose to gross tumor volume (GTV) was 10-36 Gy in 2-6 fractions. We rely on a few dosimetric parameters for quality control. The short-term efficacy was evaluated by RECIST v1.1, and the adverse event was evaluated by CTCAE V4.0. Results: The median V100, D100 and D90 of per fraction among all the patients were 88.9%±9.8%, 3.45Gy±0.54 Gy, and 5.79Gy±0.32 Gy, respectively. Dosimetric comparison between preplan and treatment plan of 20/32 patients with Type II 3D-PIT showed no significant difference in GTV volume, V100, D100, D90, conformation index (CI) and homogeneity index (HI). No severe treatment complications occurred. Grade 3 or 4 late toxicities (fistula) were observed in 3 patients (9%). The local response rate (complete remission, CR + partial remission, PR) was 84.4% (27/32) 1 month after completion of treatment. The median time to progression (TTP) was 15.4 months (95% CI 11.3- 19.6 months), 1-year local control (LC) rate were 51.7%. Conclusions: HDR-IB assisted by 3D-PIT was a reliable modality for CR-GYN due to the clinical feasibility and accepted complications.

scholarly journals Treatment Planning Methods in High Dose Rate Interstitial Brachytherapy of Carcinoma Cervix: A Dosimetric and Radiobiological Analysis

ISRN Oncology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Surega Anbumani ◽  
Pichandi Anchineyan ◽  
ArunaiNambiraj Narayanasamy ◽  
Siddanna R. Palled ◽  
Sajitha Sathisan ◽  
...  
Keyword(s):  
Dose Rate ◽  
Treatment Planning ◽  
High Dose Rate ◽  
Optimization Techniques ◽  
Interstitial Brachytherapy ◽  
Tumor Control ◽  
High Dose ◽  
Tumor Control Probability ◽  
Normal Tissues ◽  
Planning Methods

Treatment planning is a trial and error process that determines optimal dwell times, dose distribution, and loading pattern for high dose rate brachytherapy. Planning systems offer a number of dose calculation methods to either normalize or optimize the radiation dose. Each method has its own characteristics for achieving therapeutic dose to mitigate cancer growth without harming contiguous normal tissues. Our aim is to propose the best suited method for planning interstitial brachytherapy. 40 cervical cancer patients were randomly selected and 5 planning methods were iterated. Graphical optimization was compared with implant geometry and dose point normalization/optimization techniques using dosimetrical and radiobiological plan quality indices retrospectively. Mean tumor control probability was similar in all the methods with no statistical significance. Mean normal tissue complication probability for bladder and rectum is 0.3252 and 0.3126 (P=0.0001), respectively, in graphical optimized plans compared to other methods. There was no significant correlation found between Conformity Index and tumor control probability when the plans were ranked according to Pearson product moment method (r=-0.120). Graphical optimization can result in maximum sparing of normal tissues.

scholarly journals Pengaruh Pemberian Ekstrak Alga Merah (gracilaria verrucosa) terhadap Aktivitas SGPT pada Tikus Putih (rattus norvegicus) Jantan Galur Wistar yang Diinduksi Parasetamol Dosis Tinggi

2018 ◽  
Vol 7 (1) ◽  
pp. 75
Author(s):  
Akbar Maharudin Fikri ◽  
Sihning EJ Tehupuring
Keyword(s):  
Red Algae ◽  
Rattus Norvegicus ◽  
Wistar Rats ◽  
Gracilaria Verrucosa ◽  
High Dose ◽  
Test Results ◽  
Serum Glutamic Pyruvic Transaminase ◽  
Significant Difference ◽  
Male Wistar Rats ◽  
High Doses

Background: Administration of high dose paracetamol may increase the metabolic pathways that produce N-acetyl-p-benzoquinonimin (NAPQI). NAPQI is a reactive substance, resulting liver tissue damage and increase SGPT activity. Red algae extract contains flavonoids that act as antioxidants.Objectives: This research aimed to determine the effect of red algae (Gracilaria verrucosa) extract to the activity of serum glutamic pyruvic transaminase (SGPT) in male Wistar rats (Rattus norvegicus) induced by high dose paracetamol.Methodology: This research used 24 animal of Male Wistar rats. These rats were divided into 3 groups: 1) group of rats fed with standard food; 2) group of rats given paracetamol 1750 mg/kg on day 10; and 3) group of rats given red algae extract 200 mg/kg/day on day 1-11 and paracetamol 1750mg/kg on day 10. On day 11, all rats were sacrificed and SGPT activities were measured by spectrophotometry method.Result: Mann-Whitney test results showed significant difference (p = 0.021) between SGPT activity of group of rats fed with standard food (=81.95±10.103 U/L) and group of rats induced by high dose paracetamol (=97.06±11.19 U/L). Furthermore, there was significant difference (p = 0.016) between SGPT activity of group of rats induced by high dose paracetamol (=97.06±11.19 U/L) and group of rats induced by high doses of paracetamol and fed with red algae extract (=82.73±11.233 U/L).Conclusion: The conclusion of this research showed that high dose paracetamol significantly increased SGPT activity and red algae extract significantly decreased SGPT activity because it contains flavonoids that act as antioxidants.

High-dose benzodiazepine dependence among health-care professionals: A neglected phenomenon

2021 ◽  
Vol 61 (1_suppl) ◽  
pp. 42-45
Author(s):  
Laura Morbioli ◽  
Fabio Lugoboni
Keyword(s):  
Health Care ◽  
Cognitive Impairment ◽  
Health Care Professionals ◽  
University Hospital ◽  
High Dose ◽  
Work Related ◽  
Severe Withdrawal ◽  
Significant Difference ◽  
High Doses ◽  
The Impact

Chronic use of benzodiazepines (BDZs) is a widespread phenomenon which can lead to side effects such as tolerance, dependence and cognitive impairment, as well as resulting in accidents at work. High-dose BDZ dependence (HD-BDZ) is little studied, and it is mainly attributed to major psychiatric disorders and polydrug abuse. To date, few studies have investigated HD-BDZ among active workers, with none among health-care professionals (HPs). Tapering from high doses of BDZs can cause severe withdrawal symptoms, including seizures. The Addiction Unit of the University Hospital in Verona uses a protocol based on flumazenil slow infusion (FLU-SI), the safest and most effective treatment for HD-BDZ. Since 2003, 1281 patients have been detoxified from long-term use of high doses of BDZ using FLU-SI. The sample includes 139 (10.8%) HPs. Mean daily doses were 336 mg diazepam equivalent among HPs and 365 mg diazepam equivalent among non-HPs (no statistically significant difference). HPs are at higher risk of sleep disorders and work-related stress. Most of these HPs experience difficulties at work due to cognitive impairment, but they are often afraid of the potential legal implications and too ashamed to ask for help. It is important to study the prevalence of HD-BDZ among HPs and to investigate the impact on their working skills and working eligibility.

scholarly journals Per-oral interstitial brachytherapy catheter insertion for boost in case of recurrent tonsillar carcinoma: dosimetry and clinical outcome

2020 ◽  
Vol 6 (1) ◽  
pp. 20190059 ◽  
Author(s):  
Naoya Murakami ◽  
Seiichi Yoshimoto ◽  
Satoshi Nakamura ◽  
Masakazu Uematsu ◽  
Tairo Kashihara ◽  
...  
Keyword(s):  
Local Recurrence ◽  
Oropharyngeal Cancer ◽  
Intensity Modulated Radiation Therapy ◽  
Residual Tumor ◽  
High Dose Rate ◽  
Interstitial Brachytherapy ◽  
High Dose ◽  
Tonsillar Carcinoma ◽  
Normal Tissues ◽  
Per Oral

High-dose-rate interstitial brachytherapy (HDR-ISBT) is relatively rarely applied for the head and neck cancer. However, its dose distribution is more confined than intensity modulated radiation therapy (IMRT) and can deliver higher dose while sparing surrounding normal tissues. In this case report, the effectiveness of HDR-ISBT as a boost following IMRT for post-operative recurrent oropharyngeal cancer patient was indicated. A 73-year-old male who developed local recurrence after surgery for oropharyngeal squamous cell carcinoma. Salvage IMRT up to 70 Gy concurrent with weekly cetuximab was planned. However, CT taken at 60 Gy found a residual tumor, then, boost HDR-ISBT was proposed. 1 week after 60 Gy of IMRT, HDR-ISBT, 12 Gy in 2 fractions, was delivered under local anesthesia. MRI taken 2 months after HDR-ISBT showed no residual tumor. It was demonstrated that boost HDR-ISBT following IMRT for local recurrence of oropharyngeal cancer was performed safely and showed favorable efficacy.

scholarly journals Impact of different treatment plans on EQD2 for intracavitary brachytherapy of cervical cancer

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Osman Vefa Gul ◽  
Gokcen Inan ◽  
Hamit Basaran
Keyword(s):  
Cervical Cancer ◽  
Small Intestine ◽  
Organs At Risk ◽  
External Beam Radiotherapy ◽  
High Dose Rate ◽  
Intracavitary Brachytherapy ◽  
High Dose ◽  
Dose Volume Histograms ◽  
Significant Difference ◽  
Treatment Plans

Abstract Background Cancer is one of the leading causes of death worldwide. According to GLOBOCAN estimates, there were 341,831 deaths from cervical cancer in 185 countries in 2020. The aim of this study was to compare equieffective dose (EQD2) at 2 Gy per fraction by using dose volume histograms (DVHs) derived from external beam radiotherapy (EBRT) and high-dose rate brachytherapy (HDR-BRT) treatment plans used in cervical cancer radiotherapy. Methods Fifteen patients with stage IIB-IIIB cervical cancer were included in this retrospective study. Treatment with three-dimensional conformal radiotherapy (3D-CRT) or intensity-modulated radiotherapy (IMRT) was planned for all patients in 28 fractions, with a total of 50.4 Gy to be delivered to the whole pelvic region. After EBRT, manual optimization (MO) or inverse optimization (IO) HDR-BRT plans were created in 4 fractions with a total of 28 Gy. The plans obtained were grouped as IMRT + IO, IMRT + MO, 3DCRT + IO, and 3DCRT + MO by calculating EQD2s among these plans. D90, D95, and D98 values were compared in all plans for CTVHR total EQD2. In addition, EQD2 values ​for critical organs at risk (OARs) such as rectum, bladder, small intestine, and sigmoid were compared in all plans for volumes of 2 cm3, 1 cm3, and 0.1 cm3, respectively. Results There was no significant difference between the treatment groups in terms of CTVHR D90 and CTVIR D90 values; However, CTVHR D95 (p = 0.000) and CTVHR D98 (p = 0.000) values ​were found to be better in IMRT + IO technique. The IMRT + IO technique provided better protection for 2 cm3, 1 cm3, and 0.1 cm3 volumes of OARs compared to other techniques. Conclusions Considering all parameters such as CTVHR, CTVIR, rectum, bladder, small intestine, and sigmoid, combination of IMRT + IO treatment option was found to be significantly superior in total EQD2 calculations compared to other plans.

Megadose steroids in severe head injury

1983 ◽  
Vol 58 (3) ◽  
pp. 326-330 ◽  
Author(s):  
Reinder Braakman ◽  
Hubert J. A. Schouten ◽  
Marijke Blaauw-van Dishoeck ◽  
Jan M. Minderhoud
Keyword(s):  
Head Injury ◽  
High Dose ◽  
Double Blind ◽  
Content Type ◽  
High Dose Dexamethasone ◽  
Double Blind Clinical Trial ◽  
Dexamethasone Phosphate ◽  
Significant Difference ◽  
High Doses ◽  
Injured Patients

✓ A prospective double-blind clinical trial was performed on 161 patients to determine the effectiveness of high-dose steroid therapy in patients admitted comatose after a non-missile-related head injury. Patients were randomized into a high-dose dexamethasone phosphate group and a placebo group. The initial dose of 100 mg of dexamethasone was administered within 6 hours of the accident. For statistical analysis, a sequential test was chosen, using survival at 1 month as a basic criterion of effectiveness. No significant difference was found in the 1-month survival rate or in the distribution of outcome after 6 months, either within the group as a whole, or in subgroups with varying severity of brain damage on admission. The authors conclude that dexamethasone in high doses has no statistically significant effect on morbidity or mortality in head-injured patients who are comatose on admission.

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