Administration Of Brachytherapy Research Articles

Traditional Clinicopathological Biomarkers Still Determine Disease-Free and Overall Survival in Invasive Breast Cancer Patients: A Pilot Study.

Background: Molecular classification, tumor diameter, Ki67 expression, and brachytherapy administration still act as the most potent potential predictors of breast cancer recurrence and overall survival. Methods: Over the period of 23 months, we included in the study 92 invasive breast cancer (IBrC) patients initially diagnosed at the Clinical Ward of Breast Cancer and Reconstructive Surgery, Oncology Center in Bydgoszcz, Poland. The probability of disease-free survival (DFS) and overall survival (OS) in relation to potential prognostic factors for the patients were determined using a Kaplan-Meier analysis, and univariate and multivariate Cox regression analyses evaluated the predictive factors of IBrC patients. The investigation of the potential prognostic model's accuracy was analyzed using the ROC curve. Results: Patients with tumor size < 2 cm, Ki67 expression < 20%, luminal-A molecular subtype, and extra-dose brachytherapy boost administration displayed the most favorable prognosis according to breast cancer disease-free survival and overall survival. The estimated 5 year probability of DFS and OS rates in women with tumor diameter < 2 cm were 89% and 90%, respectively. In tumor diameter > 2 cm, the estimated 5 year probability of DFS was 73% and OS was 76%. Interestingly, the tumor diameter of 1.6 cm with a specificity of 60.5% and a sensitivity of 75% occurred as the best threshold point to differentiate patients with cancer recurrence from those without cancer progression. Conclusions: Our study provides essential information on the clinicopathological profile and future outcomes of early stage IBrC patients. Furthermore, the tumor diameter cut-off value of 1.6 cm discriminating between disease recurrence and those without disease progression patients represents an innovative direction for further research.

CONTEMPORARY APPROACHES TO PROGNOSTICATION AND MANAGEMENT OF PELVIC RADIATION INJURIES IN GYNECOLOGICAL CANCER PATIENTS.

Rapid development of radiotherapeutic techniques and implementation of radiation therapy (RT) nanotechnologies in practice, taking into account principles of radiobiology, ensures that the planned dose will bedelivered to the target volume with minimal irradiation of healthy tissues while maintaining the guaranteed RTquality. Therefore, further advance of RT involves not only implementation of the new technologies in radiationpractice, but also the intensive developments in fields of radiation medicine and clinical radiobiology. search for optimal models of the high-energy (HDR - high dose rate) brachytherapy (BT) using the 192Irsource in comparison with effects of the reference gamma radiation from 60Co, thereby, to increase the effectivenessof chemoradiation therapy (CRT) of gynecological cancer patients (GCPs) with minimal radiation loads on criticalorgans and tissues in the tumor environment. The radiobiological study was aimed to determine the feasibility ofusing the transmembrane potential (TMP) and intensity of reactive oxygen species (ROS) production in peripheralblood lymphocytes (PBL) as predictors of radiosensitivity of non-malignant cells from the tumor environment or itsbed in order to minimize the RT complications in GCPs. Patients (n = 115) with cancer stages II-III, T2-3N0-1M0 were managed with comprehensiveconservative treatment. Three groups of patients were selected depending on the applied HDR BT method against abackground of the administered chemosensitizing agents. Blood samples of GCPs (n = 24) before the RT initiationand of apparently healthy individuals (AHIs, i.e. the control group, n = 18) were taken for the radiobiologicalresearch. Review of the direct results of 60Co or 192Ir sources use in HDR BT and of the follow-up data showed theincreased tumor positive response in the main study groups after CRT course by respectively 16.6 % and 20.1 % incomparison with 60Со HDR BT administration. Concerning local reactions it was noted that grade II radiation reactions were almost absent in the main groups. According to the results of radiobiological studies, it was establishedthat TMP level in PBL of GCPs was 1.36 times higher than in AHIs. Thus, the emerging of late radiation injuries depended on the accuracy of of individual computer planning and correct reproduction of the planned RT course, timely correction of treatment programs, use of a complexof rational medical prophylaxis, severity of tumor process and concomitant disorders, as well as on the used type ofHDR radiation sources (192Ir and 60Co). Changes in TMP values and intensity of ROS production in PBL of GCPs in comparison with AHIs, and the high values of these parameters in PBL of individual patients are a rationale to specifythem as additional indicators characterizing the possibility of radiation complications before the RT planning.

Factors Associated with Duration of Overall Treatment Time for Cervical Cancer Treated with Definitive Chemoradiotherapy.

IntroductionFor women with intact cervical cancer treated by definitive chemoradiotherapy, the adverse impact of treatment prolongation is well-established. We aimed to identify potentially modifiable factors associated with the unwanted increase in the time required to complete the prescribed course of therapy.MethodsWe retrospectively examined treatment records of 104 consecutive cervical cancer patients receiving chemoradiation for cervical cancer, which included cervical high-dose-rate intracavitary brachytherapy performed at a single referral center. Association of factors, including distance to care, driving time, and income level with overall treatment time, was explored.ResultsGuideline-concordant treatment duration was achieved in 34% of cases. There was no significant correlation between treatment duration and any of the patient-related characteristics assessed in this study. Transitioning of the radiation oncology physician staffing at the brachytherapy center from a private practice non-integrated group to a large integrated group was associated with a decrease in mean overall treatment time, 61 vs. 68 days, p = 0.007.ConclusionsWe did not identify a modifiable patient-related factor amenable to a financial intervention. Administration of brachytherapy within an integrated system resulted in a shortened duration of the entire course of therapy for intact cervical cancer.

Racial disparities in brachytherapy administration and survival in women with locally advanced cervical cancer

ObjectiveBlack women have the highest incidence and mortality from cervical cancer in the United States. This study evaluated whether racial disparities in the receipt of brachytherapy (BT) for locally advanced cervical cancer mediate survival differences by race using the National Cancer Database. MethodsA retrospective cohort study was performed using 16,116 women with stage IB2-IVA cervical cancer treated from 2004 to 2014. Women who did not receive external beam radiation therapy, those with unknown survival data or stage, and those status post hysterectomy or pelvic exenteration were excluded. Multivariate logistic regression was performed to evaluate factors associated with BT use. Using a propensity score adjusted model with inverse probability treatment weighting, adjusted hazard ratios for overall survival were calculated, including an interaction term between BT and race. ResultsOf 16,116 patients, 19.2% were black and 55.8% received BT. Black women were significantly less likely to receive BT (AOR 0.87, 95% confidence interval [CI] 0.79–0.96, p = 0.007) and had worse all-cause mortality (median survival 3.9 years [95% CI 3.6–4.6] versus 5.2 years [95% CI 4.9–5.5] for non-black women, p < 0.001). In the adjusted model, black patients had an increased risk of death compared to non-black patients (AHR 1.14, 95% CI 1.05–1.24; p = 0.002) among women who did not receive BT. However, there was no difference in survival by race when both groups received BT (AHR 1.04, 95% CI 0.95–1.13, p = 0.42; p-interaction = 0.005). ConclusionsBlack women with locally advanced cervical cancer are less likely to receive brachytherapy, which mediates survival differences by race. Improving access to brachytherapy may improve overall survival.

American Brachytherapy Society: Brachytherapy treatment recommendations for locally advanced cervix cancer for low-income and middle-income countries

PurposeMost cervix cancer cases occur in low-income and middle-income countries (LMIC), and outcomes are suboptimal, even for early stage disease. Brachytherapy plays a central role in the treatment paradigm, improving both local control and overall survival. The American Brachytherapy Society (ABS) aims to provide guidelines for brachytherapy delivery in resource-limited settings. Methods and MaterialsA panel of clinicians and physicists with expertise in brachytherapy administration in LMIC was convened. A survey was developed to identify practice patterns at the authors' institutions and was also extended to participants of the Cervix Cancer Research Network. The scientific literature was reviewed to identify consensus papers or review articles with a focus on treatment of locally advanced, unresected cervical cancer in LMIC. ResultsOf the 40 participants invited to respond to the survey, 32 responded (response rate 80%). Participants were practicing in 14 different countries including both high-income (China, Singapore, Taiwan, United Kingdom, and United States) and low-income or middle-income countries (Bangladesh, Botswana, Brazil, India, Malaysia, Pakistan, Philippines, Thailand, and Vietnam). Recommendations for modifications to existing ABS guidelines were reviewed by the panel members and are highlighted in this article. ConclusionsRecommendations for treatment of locally advanced, unresectable cervical cancer in LMIC are presented. The guidelines comment on staging, external beam radiotherapy, use of concurrent chemotherapy, overall treatment duration, use of anesthesia, applicator choice and placement verification, brachytherapy treatment planning including dose and prescription point, recommended reporting and documentation, physics support, and follow-up.

Abstract 5730: Dosimetric properties of a new thermobrachytherapy seed with ferromagnetic core for treatment of solid tumors

Abstract Studies of the curative effects of hyperthermia and radiation therapy on treatment of cancer show a strong evidence of a synergistic enhancement when both radiation and hyperthermia modalities are applied simultaneously. Varieties of tissue heating approaches developed up to date still fail to overcome such essential limitations as an inadequate temperature control, temperature non-uniformity, and prolonged time delay between hyperthermia and radiation treatments. We propose a new self-regulating Thermobrachytherapy seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. The proposed seed is based on the BEST Seed Model 2301-I125, where tungsten marker core and the air gap are replaced with a ferromagnetic material. The ferromagnetic core produces heat when subjected to alternating electro-magnetic (EM) field and effectively shuts off after reaching the Curie temperature (TC) of the ferromagnetic material thus realizing the temperature self-regulation. We present the Monte Carlo study of dose rate constant and the other TG-43 radiation characteristic factors for the proposed seed. For the thermal characteristics, we studied a model consisting of 16 seeds placed in the central region of a cylindrical water phantom using a finite-element partial differential equation solver package “COMSOL Multiphysics”. The modeling result shows that temperature of the thermoseed surface rises rapidly and stays constant around TC of the ferromagnetic material. The amount of heat produced by the ferromagnetic core is sufficient to raise the temperature of the surrounding volume to the therapeutic range. The volume of the therapeutic temperature range increases with increase of frequency or magnetic field strength. These studies demonstrate that an optimal isothermal distribution can be achieved on a target volume to match with the radiation isodose distribution for the seed configuration by tuning frequency and intensity of the alternating magnetic field. The proposed combination seed model has a high potential for implementation of concurrent brachytherapy and hyperthermia. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5730. doi:1538-7445.AM2012-5730

TU-D-BRB-05: Three-Dimentional Dosimetric and Thermal Properties of a Newly Developed Ferromagnetic Core Thermobrachytherapy Seed for Treatment of Solid Tumors

Purpose: Studies of the curative effects of hyperthermia and radiation therapy on treatment of cancer show a strong evidence of a synergistic enhancement when two modalities are applied simultaneously. Varieties of tissue heating approaches developed up to date still fail to overcome such essential limitations as an inadequate temperature control, temperature non‐uniformity, and prolonged time delay between hyperthermia and radiation treatments. We propose a new self‐regulating Thermobrachytherapy seed, which serves as a source of both radiation and heat for concurrent administration of brachytherapy and hyperthermia. Methods: The proposed seed is based on the BEST Model 2301‐I125, where tungsten marker is replaced with a ferromagnetic material. The ferromagnetic core produces heat when subjected to alternating electro‐magnetic (EM) field and effectively shuts off after reaching its Curie temperature thus realizing the temperature self‐regulation. We studied a model consisting 32 seeds, placed in the central region of a cylindrical water phantom. The temperature distribution thorough the volume surrounding the seeds was modeled using a finite‐element partial differential equation solver package “COMSOL Multiphysics” for different EM field parameters. Results:Temperature of the thermoseed surface rises rapidly and stays constant around Curie temperature of the ferromagnetic material (Cu‐Ni alloy) used. The amount of heat produced by the ferromagnetic core is sufficient for raising the temperature of the surrounding volume to the therapeutic range. The volume of the therapeutictemperature range increases with increase of frequency or magnetic field. The temperature distribution is tunable based on the number of seeds used, their locations, magnetic field strength, and its frequency. Conclusion: The amount of heat produced by the seeds is sufficient for achieving the therapeutictemperature range in the surrounding volume when the appropriate frequency and magnetic field is applied. Our study demonstrates feasibility of the proposed combinational seed for clinical implementation of concurrent brachytherapy and hyperthermia.