Predictive value of magnetic resonance imaging diffusion parameters using artificial intelligence in low-and intermediate-risk prostate cancer patients treated with stereotactic ablative radiotherapy: A pilot study.

INTRODUCTION: To investigate the predictive value of the pre-treatment diffusion parameters of diffusion-weighted magnetic resonance imaging (DW-MRI) using artificial intelligence (AI) for prostate-specific antigen (PSA) response in patients with low- and intermediate-risk prostate cancer (PCa) treated with stereotactic ablative radiotherapy (SABR). METHODS: Retrospective evaluation was performed for 30 patients using pre-treatment multi-parametric MR image datasets between 2017 and 2021. MR-based mean- and minimum apparent diffusion coefficients (ADCmean, ADCmin) were calculated for the intraprostatic dominant lesion. Therapeutic response was assessed using PSA levels. Predictive performance was assessed by the receiver operating characteristic (ROC) analysis. Statistics performed with a significance level of p ≤ 0.05. RESULTS: No biochemical relapse was detected after a median follow-up of twenty-three months (range: 3-50), with a median PSA of 0.01 ng/ml (range: 0.006-2.8) at the last examination. Significant differences were observed between the pre-treatment ADCmean, ADCmin parameters, and the group averages of patients with low and high 1-year-PSA measurements (p < 0.0001, p < 0.0001). In prediction, the random forest (RF) model outperformed the decision tree (DT) and support vector machine (SVM) models by yielding area under the curves (AUC), with 0.722, 0.685, and 0.5, respectively. CONCLUSION: Our findings suggest that pre-treatment MR diffusion data may predict therapeutic response using the novel approach of machine learning in PCa patients treated with SABR. IMPLICATIONS FOR PRACTICE: Clinicians shall measure and implement the evaluation of the suggested parameters (ADCmin, ADCmean) to provide the most accurate therapy for the patient.

Feasibility evaluation of prone breast irradiation with the Sagittilt© system including residual-intrafractional error assessment.

PURPOSE: Feasibility evaluation of the Sagittilt© prone breast board system (Orfit Industries, Wijnegem, Belgium) for radiotherapy focusing on patient and staff satisfaction, treatment time, treatment reproducibility with the assessment of residual-intrafractional errors. MATERIAL AND METHODS: Thirty-six patients underwent whole-breast irradiation in prone position. Seventeen received a sequential boost (breast: 42.56Gy in 16 fractions, boost: 10Gy in five fractions), while 19 patients received a concomitant boost protocol (breast/boost: 45.57/55.86Gy in 21 fractions). Treatment verification included a daily online cone-beam CT (CBCT). In order to assess the residual and residual-intrafractional errors post-treatment CBCTs were performed systematically at the first five treatment sessions. Treatment time, patient comfort, staff satisfaction were also evaluated. RESULTS: The pretreatment CBCT resulted in a population systematic error of 4.5/3.9/3.3mm in lateral/longitudinal/vertical directions, while the random error was 5.4/3.8/2.8mm. Without correction these would correspond to a clinical to planning target volume margin of 15.0/12.3/10.3mm. The population systematic and random residual-intrafractional errors were 1.5/0.9/1.7mm and 1.7/1.9/1.6mm. Patient and staffs' satisfaction were considered good and average. The mean treatment session time was 21minutes (range: 13-40min). CONCLUSION: The Sagittilt© system seems to be feasible for breast irradiation and well-tolerated by patients, acceptable to radiographers and reasonable in terms of treatment times. Set-up accuracy was comparable with other prone systems; residual errors need further investigations.

Oncological and surgical outcome after oncoplastic breast surgery.

BACKGROUND: Oncoplastic surgery combines breast-conserving treatment and plastic surgery techniques. The aim of the study was to identify breast and tumor-related characteristics that contribute to the rate of complications and recurrence. METHODS: This retrospective study included 72 patients with a median follow-up of 32 months. For each patient, a comprehensive set of data was collected, including epidemiology, tumor characteristics, preoperative information, detailed pathology reports, radiotherapy treatment and type of surgical technique. The rate of complications, recurrence and survival were studied. RESULTS: Complete tumor removal was performed with clear margins in all patients but in 25 of them margins were less than 2 mm. One patient had local recurrence and another developed distant metastases. The study showed that the size of the margin was not predictive of recurrence as long as not positive; the greater the resection volume, the larger the excision margin. The resection size was the only factor influencing complications and no specific tumor-related factor significantly increased the complication rate. Surgical complications did not delay the initiation of chemotherapy and radiotherapy. CONCLUSIONS: This is the first oncoplastic study where both tumor and breast characteristics were analyzed using the most recent criteria of the literature. Oncoplastic surgery can be considered as oncologically safe. The resection size was the sole significant risk factor for postoperative complications. Complications after oncoplastic breast surgery did not differ neoadjuvant therapy. Long-term event-free survival was excellent (96% at 7 years).

Oncological and Surgical Outcome after Oncoplastic Breast Surgery.

BACKGROUND: Oncoplastic surgery combines breast-conserving treatment and plastic surgery techniques. The aim of the study was to identify breast and tumor-related characteristics that contribute to the rate of complications and recurrence. MATERIAL & METHODS: This retrospective study included 72 patients with a median follow-up of 32 months. For each patient, a comprehensive set of data was collected, including epidemiology, tumor characteristics, preoperative information, detailed pathology reports, radiotherapy treatment and type of surgical technique. The rate of complications, recurrence and survival were studied. RESULTS: Complete tumor removal was performed with clear margins in all patients but in 25 of them margins were less than 2 mm. One patient had local recurrence and another developed distant metastases. The study showed that the size of the margin was not predictive of recurrence as long as not positive; the greater the resection volume, the larger the excision margin. The resection size was the only factor influencing complications and no specific tumor-related factor significantly increased the complication rate. Surgical complications did not delay the initiation of chemotherapy and radiotherapy. CONCLUSION: This is the first oncoplastic study where both tumor and breast characteristics were analyzed using the most recent criteria of the literature. Oncoplastic surgery can be considered as oncologically safe. The resection size was the sole significant risk factor for postoperative complications. Complications after oncoplastic breast surgery did not differ neoadjuvant therapy. Long-term event-free survival was excellent (96% at 7 years).

[Functional imaging and radiotherapy]. / Utilisation de l'imagerie fonctionnelle en radiothérapie.

Medical imaging plays a crucial role in the diagnosis, staging and therapeutic strategy of oncologic patients. The development of medical imaging over the last decade has allowed significant progresses in radiotherapy. Indeed, medical imaging is now considered the corner stone of radiotherapy. The main challenge for the radiation oncologist consists in the tumour identification with a view to irradiate the tumour at a curative dose while avoiding healthy tissues. To achieve these goals, the radiotherapist daily uses anatomical imaging such as computed tomography (CT) or magnetic resonance imaging (MRI). Since several years now, the development of functional imaging such as positron emission tomography (PET) combined with CT or functional MRI has opened new perspectives in the management of oncologic diseases. Indeed, these imaging techniques offer new information on tumour metabolism that may be taken into account to plan the radiotherapy treatment. This article illustrates the different imaging techniques used in radiotherapy and the role of functional imaging for establishing new therapeutic strategies in radiation oncology.

[Breast irradiation: ready to wear or customized?]. / Radiothérapie mammaire: prêt-à-porter ou sur mesure?

Irradiation after conservative breast surgery (CBS) for DCIS (ductal carcinoma in situ) and infiltrating ductal and lobular carcinoma is considered "standard". However, radiation oncologists are raising the question whether for a well defined cohort of patients this adjuvant treatment can be individualized. The published evidence indicates that individualization should be carefully evaluated, as in no single scenario radiotherapy was not able to significantly reduce the cumulative incidence of local recurrence. Even if adjuvant radiation after CBS should be applied to virtually all patients, radiation oncologists are raising questions about the modalities of breast irradiation which could potentially be adapted to patient- and tumor-characteristics. In an ideal world, we should be able to perform robust prognostic and predictive tests to define a sub cohort of patients which really benefits from this adjuvant treatment. It might be possible that in a near future, we will rely on gene signatures to make these choices. However, the research in the field raises a lot of discussion in the scientific community and there is no real consensus nowadays on their added clinical value.

[Radiotherapy in breast cancer: current standards of treatment, prediction of local recurrence and open questions]. / Radiothérapie et cancer du sein: "standards" de traitement, prédiction de rechute locale et questions ouvertes.

Adjuvant radiotherapy after surgery is a ("well-established standard" in routine clinical practice for breast cancer. Nevertheless, a variety of questions still remain unanswered. We intend to illustrate the overall importance of radiotherapy in breast cancer and highlight some unresolved questions by quoting presentations recently made at ASTRO-2010. More and more emphasis is put on the idea of an individual approach. Predicting the individual local recurrence risk is the search for the "Holy Grail". Methods such as nomograms and genomic profiling are currently tested but need to be validated before their widespread clinical application.

Dynamic MR based analysis of tumor movement in upper and mid lobe localized lung cancer.

BACKGROUND AND PURPOSE: Tumor motion is a very important factor in the radiotherapy of lung cancer. Uncertainty resulting from tumor movement must be considered in 3D therapy planning especially in case of IMRT or stereotactic therapy. The aim of our dynamic MR based study was to detect tumor movements in upper and mid lobe lung tumors. PATIENT AND METHODS: Twenty-four patients with newly diagnosed stage II-IV lung cancer were enrolled into the study. According to tumor localization in the right S1-S3 segments 9, in the right S4-S6 segments 2, in the left S1-S3 segments 9 and in the left S4-S6 segments 4 lesions were detected. In normal treatment position individual dynamic MR examinations were performed in axial, sagittal and coronal planes (100 slices/30 sec). For tumor motion analysis E-RAD PAC's software was used. RESULTS: Movements of the tumor under normal breathing conditions were registered in the three main directions. The mean antero-posterior deviation was 0,109 cm (range: 0,063 cm-0,204 cm), the mean medio-lateral deviation was 0,114 cm (range: 0,06 cm- 0,244 cm). The greatest deviation was measured in cranio-caudal direction (mean: 0,27 cm, range: 0,079 cm- 0,815 cm). The mean direction independent deviation was 0,18 cm (range: 0,09 cm- 0,48 cm). CONCLUSION: Dynamic MR is a sensitive and well tolerated method for tumor motion monitoring in high precision 3D therapy planning of lung cancer patients. Our results demonstrate that tumors located in the upper and mid lobes have moderate breath synchronous movements. The greatest deviation occur in cranio-caudal direction.