Cancer Radiotherapie最新文献

Purpose

The main objective of this study was to assess inter- and intrafraction errors for two patient immobilisation devices in the context of lung stereotactic body radiation therapy: a vacuum cushion and a simple arm support.

Materials and methods

Twenty patients who were treated with lung stereotactic body radiation therapy in supine position with arms above their head were included in the study. Ten patients were setup in a vacuum cushion (Bluebag™, Elekta) and ten other patients with a simple arm support (Posirest™, Civco). A pretreatment four-dimensional cone-beam computed tomography and a post-treatment three-dimensional cone-beam computed tomography were acquired to compare positioning and immobilisation accuracy. Based on a rigid registration with the planning computed tomography on the spine at the target level, translational and rotational errors were reported.

Results

The median number of fractions per treatment was 5 (range: 3–10). Mean interfraction errors based on 112 four-dimensional cone-beam computed tomographies were similar for both setups with deviations less than or equal to 1.3 mm in lateral and vertical direction and 1.2° in roll and yaw. For longitudinal translational errors, mean interfraction errors were 0.7 mm with vacuum cushion and –3.9 mm with arm support. Based on 111 three-dimensional cone-beam computed tomographies, mean lateral, longitudinal and vertical intrafraction errors were –0.1 mm, –0.2 mm and 0.0 mm respectively (SD: 1.0, 1.2 and 1.0 mm respectively) for the patients setup with vacuum cushion, and mean vertical, longitudinal and lateral intrafraction errors were –0.3 mm, –0.7 mm and 0.1 mm respectively (SD: 2.3, 1.8 and 1.4 mm respectively) for the patients setup with arm support. Intrafraction errors means were not statistically different between both positions but standard deviations were statistically larger with arm support.

Conclusion

The results of our study showed similar inter and intrafraction mean deviations between both positioning but a large variability in intrafraction observed with arm support suggested a more accurate immobilization with vacuum cushion.

Purpose

Many cancer patients develop bone metastases, however the prognosis of overall survival differs. To provide an optimal treatment for these patients, especially towards the end of life, a reliable prediction of survival is needed. The goal of this study was to find new clinical factors in relation to overall survival.

Materials and methods

Prospectively 22 clinical factors were collected from 734 patients. The Kaplan–Meier and Cox regression models were used.

Results

Most patients were diagnosed with lung cancer (29%), followed by prostate (19.8%) and breast cancer (14.7%). Median overall survival was 6.4 months. Fourteen clinical factors showed significance in the univariate analyses. In the multivariate analyses 6 factors were found to be significant for the overall survival: Karnofsky performance status, primary tumor, gender, total organs affected, morphine use and systemic treatment options after radiotherapy.

Conclusion

Morphine use and systemic treatment options after radiotherapy, Karnofsky performance status, primary tumor, gender and total organs affected are strong prediction factors on overall survival after palliative radiotherapy in patients with bone metastasis. These factors are easily applicable in the clinic.

Obtaining consent to care requires the radiation oncologist to provide loyal information and to ensure that the patient understands it. Proof of such an approach rests with the practitioner. The French Society for Radiation Oncology (SFRO) does not recommend the signature of a consent form by the patient but recommends that the radiation oncologist be able to provide all the elements demonstrating the reality of a complete information circuit.

Purpose

MRI is essential in the management of brain tumours. However, long waiting times reduce patient accessibility. Reducing acquisition time could improve access but at the cost of spatial resolution and diagnostic quality. A commercially available artificial intelligence (AI) solution, SubtleMR™, can increase the resolution of acquired images. The objective of this prospective study was to evaluate the impact of this algorithm that halves the acquisition time on the detectability of brain lesions in radiology and radiotherapy.

Material and methods

The T1/T2 MRI of 33 patients with brain metastases or meningiomas were analysed. Images acquired quickly have a matrix divided by two which halves the acquisition time. The visual quality and lesion detectability of the AI images were evaluated by radiologists and radiation oncologist as well as pixel intensity and lesions size.

Results

The subjective quality of the image is lower for the AI images compared to the reference images. However, the analysis of lesion detectability shows a specificity of 1 and a sensitivity of 0.92 and 0.77 for radiology and radiotherapy respectively. Undetected lesions on the IA image are lesions with a diameter less than 4 mm and statistically low average gadolinium-enhancement contrast.

Conclusion

It is possible to reduce MRI acquisition times by half using the commercial algorithm to restore the characteristics of the image and obtain good specificity and sensitivity for lesions with a diameter greater than 4 mm.

Purpose

The increased risk of second cancer after prostate radiotherapy is a debated clinical concern. The objective of the study was to assess the risk of occurrence of second cancers after prostate radiation therapy based on the analysis the literature, and to identify potential factors explaining the discrepancies in results between studies.

Materials and methods

A review of the literature was carried out, comparing the occurrence of second cancers in patients all presenting with prostate cancer, treated or not by radiation.

Results

This review included 30 studies reporting the occurrence of second cancers in 2,112,000 patients treated or monitored for localized prostate cancer, including 1,111,000 by external radiation therapy and 103,000 by brachytherapy. Regarding external radiation therapy, the average follow-up was 7.3 years. The majority of studies (80%) involving external radiation therapy, compared to no external radiation therapy, showed an increased risk of second cancers with a hazard ratio ranging from 1.13 to 4.9, depending on the duration of the follow-up. The median time to the occurrence of these second cancers after external radiotherapy ranged from 4 to 6 years. An increased risk of second rectal and bladder cancer was observed in 52% and 85% of the studies, respectively. Considering a censoring period of more than 10 years after irradiation, 57% and 100% of the studies found an increased risk of rectal and bladder cancer, without any impact in overall survival. Studies of brachytherapy did not show an increased risk of second cancer. However, these comparative studies, most often old and retrospective, had many methodological biases.

Conclusion

Despite numerous methodological biases, prostate external radiation therapy appears associated with a moderate increase in the risk of second pelvic cancer, in particular bladder cancer, without impacting survival. Brachytherapy does not increase the risk of a second cancer.

Purpose

Commercial vendors have created artificial intelligence (AI) tools for use in all aspects of life and medicine, including radiation oncology. AI innovations will likely disrupt workflows in the field of radiation oncology. However, limited data exist on using AI-based chatbots about the quality of radiation oncology information. This study aims to assess the accuracy of ChatGPT, an AI-based chatbot, in answering patients’ questions during their first visit to the radiation oncology outpatient department and test knowledge of ChatGPT in radiation oncology.

Material and methods

Expert opinion was formulated using a set of ten standard questions of patients encountered in outpatient department practice. A blinded expert opinion was taken for the ten questions on common queries of patients in outpatient department visits, and the same questions were evaluated on ChatGPT version 3.5 (ChatGPT 3.5). The answers by expert and ChatGPT were independently evaluated for accuracy by three scientific reviewers. Additionally, a comparison was made for the extent of similarity of answers between ChatGPT and experts by a response scoring for each answer. Word count and Flesch-Kincaid readability score and grade were done for the responses obtained from expert and ChatGPT. A comparison of the answers of ChatGPT and expert was done with a Likert scale. As a second component of the study, we tested the technical knowledge of ChatGPT. Ten multiple choice questions were framed with increasing order of difficulty – basic, intermediate and advanced, and the responses were evaluated on ChatGPT. Statistical testing was done using SPSS version 27.

Results

After expert review, the accuracy of expert opinion was 100%, and ChatGPT's was 80% (8/10) for regular questions encountered in outpatient department visits. A noticeable difference was observed in word count and readability of answers from expert opinion or ChatGPT. Of the ten multiple-choice questions for assessment of radiation oncology database, ChatGPT had an accuracy rate of 90% (9 out of 10). One answer to a basic-level question was incorrect, whereas all answers to intermediate and difficult-level questions were correct.

Conclusion

ChatGPT provides reasonably accurate information about routine questions encountered in the first outpatient department visit of the patient and also demonstrated a sound knowledge of the subject. The result of our study can inform the future development of educational tools in radiation oncology and may have implications in other medical fields. This is the first study that provides essential insight into the potentially positive capabilities of two components of ChatGPT: firstly, ChatGPT's response to common queries of patients at OPD visits, and secondly, the assessment of the radiation oncology knowledge base of ChatGPT.

Purpose

Breast-conserving surgery followed by reirradiation for a localized ipsilateral breast tumour relapse may increase the radiation dose delivered to the heart and result in a greater risk of cardiac adverse events. This study aimed to compare the incidence of cardiac mortality in patients treated for a localized ipsilateral breast tumour relapse, either with breast-conserving surgery followed by reirradiation or with total mastectomy between 2000 and 2020.

Materials and methods

All patients treated for a primary non-metastatic breast cancer with breast-conserving surgery and adjuvant radiotherapy were identified in the Surveillance, Epidemiology, and End Results (SEER) program database, and those who subsequently experienced a localized ipsilateral breast tumour relapse treated with breast-conserving surgery and reirradiation (“BCS + ReRT” group, n = 239) or with total mastectomy (“TM” group, n = 3127) were included. The primary objective was to compare the cardiac mortality rate between the patients who underwent breast-conserving surgery followed by reirradiation and total mastectomy. Secondary endpoints were overall survival and cancer specific survival.

Results

Cardiac mortality was significantly higher in patients treated with breast-conserving surgery followed by reirradiation (hazard ratio [HR]: 2.40, 95% confidence interval [95% CI]: 1.19–4.86, P = 0.006) in univariate analysis; non-statistically significant differences were observed after adjusting for age, laterality and chemotherapy on multivariate analysis (HR: 1.96, 95% CI: 0.96–3.94, P = 0.067), age being the only confounding factor. A non-statistically significant difference towards lower overall survival was observed in patients who had breast-conserving surgery followed by reirradiation compared with those who underwent total mastectomy (HR: 1.37, 95% CI: 0.98–1.90, P = 0.066), and no differences were observed in terms of cancer specific survival (HR: 1.01, 95% CI: 0.56–1.82, P = 0.965).

Conclusion

In this study, the incidence of cardiac mortality was low, and breast-conserving surgery followed by reirradiation did not independently increased the risk of cardiac mortality for a localized ipsilateral breast tumour relapse.

Objectif de l’étude

La chirurgie conservatrice du sein suivie d’une réirradiation pour une rechute localisée d’une tumeur du sein homolatérale peut augmenter la dose délivrée au cœur et entraîner théoriquement un risque plus élevé de toxicité cardiaque. Cette étude visait à comparer l’incidence de la mortalité cardiaque chez les patientes prises en charge pour une tumeur du sein homolatérale, soit par chirurgie conservatrice du sein suivie d’une réirradiation, soit par mastectomie