High spatial resolution inorganic scintillator detector for high energy X-ray beam at small field irradiation

International audiencePurpose: Small fielddosimetry for radiotherapy is one of the major challenges due to the size of most dosimeters,e.g. sufficient spatial resolution, accurate dose distribution and energy dependency of the detector. In this context, the purpose of this research is to develop a small size scintillating detector targeting small field dosimetry and compare its performance with other commercial detectors. Method: An inorganic scintillator detector (ISD) of about 200 μm outer diameter was developed and tested through different small fields dosimetric characterization under high energy photons (6 MV and 15 MV) delivered by an Elekta Linear Accelerator (LINAC). PDD and beam profile measurements were compared using dosimeters from PTW namely, microdiamond and PinPoint 3D detector. A background fiber method has been considered to quantifyand eliminate the minimal Cerenkov effect from the total optical signal magnitude. Measurements were performed inside a water phantom under IAEA Technical reports series recommendations (IAEA TRS 381 and TRS 483). Results:Small fields ranging from 3 x 3 cm2, down to 0.5 x 0.5 cm2 were sequentiallymeasured using the ISD and commercial dosimeters, and a good agreement was obtained among all measurements. The result also shows that, scintillating detector has good repeatabilityand reproducibility of the output signal with maximum deviation of 0.26% and 0.5% respectively. The Full Width Half Maximum (FWHM) was measured 0.55 cm for the smallest available square size field of 0.5 x 0.5 cm2, where the discrepancy of 0.05 cm is dueto the scattering effects inside the water and convolution effect between field and detector geometries. Percentage Depth Dose (PDD) factor dependence variation with water depth exhibits nearly the same behavior for all tested detectors. The ISD allows to perform dose measurements at a very high accuracy from low (50 cGy/min) to high dose rates (800 cGy/min) and found to be independent of dose rate variation. The detection system also showed an excellent linearity with dose; hence calibration was easily achieved. Conclusions: The developed detector can be used to accurately measure the delivered dose at small field during the treatment of small volume tumors. The author’s measurement shows that despite using a non-water equivalent detector, the detector can be a powerful candidate for beam characterization and quality assurance in e.g., radiosurgery, Intensity Modulated Radiotherapy (IMRT), and brachytherapy. Our detector can provide real-time dose measurement and good spatial resolution with immediate readout, simplicity, flexibility, and robustness

Physicians’ Opinion on Intraoperative Radiotherapy as a Therapeutic De-Escalation Option in Older Women with Early Breast Cancer

Background: Intraoperative radiotherapy (IORT) is a therapeutic de-escalation option in older women with low-risk early breast cancer (EBC). A qualitative study was implemented to describe EBC physicians’ points of view on IORT as a de-escalation option. Methods: Recorded face-to-face and telephone semi-structured interviews were conducted among diverse physicians from seven French comprehensive cancer centers. Interview transcripts were grouped as corpus to construct a typology. Thematic analysis was performed. Results: Positions toward IORT were contrasted between the 16 participating physicians. Five fully supported IORT as a de-escalation option, four were not in favor, and seven had a more reserved or neutral opinion. Points of divergence concerned treatment efficacy, treatment duration, side effects and sequelae, psychological impact, compliance with adjuvant endocrine therapy, logistical constraints, financial cost, and availability of other techniques of partial breast irradiation. Physicians in favor of IORT emphasized direct benefits for the patient, and those against pointed the lack of specific guidelines, risk of lost opportunity in older women with long life expectancy, and challenges of shared decision making. Conclusions: Despite national policies to preserve cancer patients’ quality of life and increase their participation in medical decision making, therapeutic de-escalation using IORT is not consensual among physicians. Further efforts are needed to promote patient-centered care

Physicians’ Opinion on Intraoperative Radiotherapy as a Therapeutic De-Escalation Option in Older Women with Early Breast Cancer

International audienceBackground: Intraoperative radiotherapy (IORT) is a therapeutic de-escalation option in older women with low-risk early breast cancer (EBC). A qualitative study was implemented to describe EBC physicians' points of view on IORT as a de-escalation option.Methods: Recorded face-to-face and telephone semi-structured interviews were conducted among diverse physicians from seven French comprehensive cancer centers. Interview transcripts were grouped as corpus to construct a typology. Thematic analysis was performed.Results: Positions toward IORT were contrasted between the 16 participating physicians. Five fully supported IORT as a de-escalation option, four were not in favor, and seven had a more reserved or neutral opinion. Points of divergence concerned treatment efficacy, treatment duration, side effects and sequelae, psychological impact, compliance with adjuvant endocrine therapy, logistical constraints, financial cost, and availability of other techniques of partial breast irradiation. Physicians in favor of IORT emphasized direct benefits for the patient, and those against pointed the lack of specific guidelines, risk of lost opportunity in older women with long life expectancy, and challenges of shared decision making.Conclusions: Despite national policies to preserve cancer patients' quality of life and increase their participation in medical decision making, therapeutic de-escalation using IORT is not consensual among physicians. Further efforts are needed to promote patient-centered care

Self-management Strategies Adopted by Breast Cancer Survivors to Improve their Adherence to Tamoxifen

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Women's perceptions and experience of adjuvant tamoxifen therapy account for their adherence: breast cancer patients' point of view

International audienceObjective: The aim of this study on primary breast cancer patients undergoing adjuvant tamoxifen treatment was to determine how their perceptions of the treatment and their experience of side-effects contributed to their adherence to the treatment. Methods: A consecutive series of primary breast cancer patients eligible for tamoxifen therapy were studied qualitatively by conducting semi-structured in-depth interviews at two French cancer centres. Results: The women aged 35-65 (N 5 34) were struggling with several issues involving their understanding and experience of the treatment, which have not been documented so far. These issues included confusion about the 'hormonal' nature and activity of tamoxifen and the etiology of the changes in their menopausal status, as well as the symbolic associations formed by patients about the paradox of taking a treatment that has aging effects but saves lives. Conclusions: This study shows the great physical burden often associated with tamoxifen treatment and brings to light women's own complex representations of the treatment and their interpretation of the side-effects. Better communication between health-care providers and patients should ultimately help to prevent refusal or discontinuation of tamoxifen treatment

Early clinical outcomes of hybrid brachytherapy for locally advanced cervical cancer: making adverse situations in a favorable scenario

PURPOSE: To investigate the feasibility and early clinical outcomes of combined intra-cavitary (IC) and interstitial (IS) image-guided adaptive brachytherapy (IGABT) as curative and definitive treatment of patients treated with chemoradiotherapy (CCRT) for locally advanced cervical cancer (LACC). MATERIAL AND METHODS: Data from medical records of all consecutive patients with histologically proven cervical cancer (FIGO 2018 stage IB-IV), treated by brachytherapy after CCRT at our institution between 2017 and 2020 were reviewed. RESULTS: One hundred and forty-two patients with LACC FIGO 2018 stages (IB: 20.4%, II: 31.7%, III: 45.8%, IV: 2.1%) underwent brachytherapy at our institution, out of which 53.5% underwent combined brachytherapy technique (IC/IS). Median number of implanted catheters was 3 (range, 1-6 catheters). None of the 142 patients required invasive hemorrhage management. With a median follow-up of 21.6 (95% CI [confidence interval]: 19.1-23.5%) months, local relapse was observed in nine patients (6.3%), with four showing persistent and progressive disease. The estimated 2-year local and pelvic relapse-free survival were 92% (95% CI: 84-96%) and 90% (95% CI: 83-94%), respectively. The estimated 2-year disease-free survival for the entire population was 80% (95% CI: 71-87%). The 2-year overall survival (OS) rate for the entire population was 92% (95% CI: 84-96%). Acute toxicity G3 was reported in two (1.4%) patients. High-grade late toxicity (grade 3) was reported in 9 (6.3%) patients. CONCLUSIONS: Combined IC/IS brachytherapy for LACC allows for recommended doses to achieve local control even in large tumors after CCRT improving target volume coverage, with low rates of acute morbidity. Hybrid brachytherapy technique (IC/IS) is essential to have a favorable scenario at the time of brachytherapy to correctly treat locally advanced cervical cancer patients

Lived experience and perceived advantages of therapeutic De-escalation: A qualitative study of older patients with breast cancer

One option for therapeutic de-escalation in older women with early breast cancer (EBC) is partial breast irradiation (PBI) instead of whole-breast irradiation (WBI) when the latter has no clear advantages. We aimed to explore the decision-making processes and the lived experiences of WBI and PBI from the perspectives of older women with EBC. Materials and methods: Thematic content analysis was performed on qualitative data collected using narrative interviews. Results: Twenty-two women aged 65 and over participated (ten patients who underwent WBI and twelve who underwent PBI). We identified three themes from their narratives: 1) Acceptance of a paternalistic relationship with physicians, 2) Strong need for an informed choice, and 3) PBI can help people conceal cancer-related physical marks. Narratives underlined participants' preferences for each of the two treatments and their perceptions about therapeutic de-escalation. Misconceptions about therapeutic de-escalation were observed. Discussion: When providing information about EBC treatment options, patients' perceived burden of side effects should be considered. Moreover, eliciting the value older patients place on available breast cancer treatments, as well as their related goals and preferences, could foster their participation in the therapeutic de-escalation decision-making process

P6-05-40: Aqua polo: Preliminary feasibility and efficacy study of a programme of adapted, supervised water polo to reduce fatigue and improve women’s psychological and social recovery after breast cancer treatment. A mixed-method design

International audienceIntroduction : Physical activity has been shown to have many benefits, including reducing cancer-related fatigue (CRF) and improving psychological and physical recovery from breast cancer. Some authors have shown the benefits of aquatic practice, while others have detailed the benefits of group and supervised practice. We hypothesise that an innovative sports coaching proposal could allow a significant adherence of patients and contribute to their health improvement. The main objective is to study the feasibility of an adapted water polo programme (aqua polo) for women after breast cancer. Secondary we will analyse the effect of such a practice on patients’ recovery and to study the relationship between coaches and participants. The use of mixed methods will allow to question precisely the underlying processes. Methods and analysis : This is a prospective, non-randomised, monocentric study with a sample of 24 breast cancer patients after treatment. The intervention is a 20 week programme (1 session per week) of aqua polo in a real sports setting. The variables measured are patient participation, quality of life (QLQ BR23), CRF (R-PFS) and post-traumatic growth (PTG-I) as well as different variables to observe physical capacity (strength with dynamometer, step-test and arm amplitude). The quality of the coach-patient relationship will be evaluated (CART-Q) to explore its dynamics. Participatory observations and interviews will be carried out to report on the interactions between the coach and the participants during the sessions. Ethics and dissemination : Study procedures have been approved by the Institutional Review Board of the Institute (IPC 2019-028) and the National Ethics Committee (SI:20.01.20.54741). Consent is given in person to each participant. The information collected on the participants contain only a non-identifiable study identifier. The results of this protocol will be published in a scientific paper and communicated to the medical staff of the medical center. Trial registration number ID-RCB: 2019-A03003-54 Keywords: Quality of the relationship, Aquatic exercise, Quality of life, Sport Citation Format: Sarah Cuvelier, Charlène Goetgheluck-Villaron, Monique Cohen, Agnès Tallet, Leonor Lopez Almeida, Jean-Marie Boher, Sophia Jowett, Sébastien Justafré, Pierre Dantin, Patrice Viens, Sarah Calvin. Aqua polo: Preliminary feasibility and efficacy study of a programme of adapted, supervised water polo to reduce fatigue and improve women’s psychological and social recovery after breast cancer treatment. A mixed-method design. [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P6-05-40