Radiation recall dermatitis after oral cyclophosphamide

peer reviewedRadiation recall dermatitis is an inflammatory skin reaction occurring in a previously irradiated field following the delivery of a promoting agent. It has been described after a number of antineoplastic agents such as gemcitabine, taxanes, anthracyclines. We report the case of a 50-year-old man with metastatic prostate cancer who developed two consecutive radiation recall dermatitis episodes triggered by oral cyclophosphamide. They occurred 4 to 5 weeks after palliative radiotherapy on bone metastasis. Spontaneous resolution was observed within 6 weeks after discontinuation of cyclophosphamide and with local supportive care. To our knowledge this is the first reported case of radiation recall dermatitis after oral cyclophosphamide

Incidence, risk factors, and CT characteristics of radiation recall pneumonitis induced by immune checkpoint inhibitor in lung cancer.

BACKGROUND AND PURPOSE: Radiation recall pneumonitis (RRP) is a delayed radiation-induced lung toxicity triggered by systemic agents, typically anticancer drugs. Immune checkpoint inhibitors (ICIs) have recently been identified as potential causal agents of RRP but its real incidence and potential risk factors remain unknown. MATERIALS AND METHODS: Medical records and CTs of patients treated with programmed death 1 (PD-1) or programmed death ligand 1 (PD-L1) inhibitors for advanced lung cancer between 2014 and 2019 at our tertiary center, and who had a previous history of lung irradiation were retrospectively analyzed. We identified RRP as lung CT modifications occurring in the irradiation field >6 months after conventionally fractionated radiotherapy completion and >1 year after stereotactic body radiation therapy. Clinical and dosimetric data were analyzed to identify potential risk factors for RRP. RESULTS: Among 348 patients treated with ICIs, data from 80 eligible patients were analyzed (median age, 69 years [interquartile range, 11]; 45 men). Fifteen patients (18.8%) presented with RRP. Median time between end of radiotherapy and RRP was 450 days (range, 231-1859). No risk factor was significantly associated with RRP. ICI-related pneumonitis was associated with RRP in 33.3% of cases (p = 0.0021), developing either concomitantly or after RRP. Incidence of grade ≥ 3 pneumonitis in the RRP population was 13.3 %. CONCLUSION: We demonstrated a high incidence of RRP (18.8%) in our population of previously irradiated patients treated with ICIs for lung cancer. We identified no risk factors for RRP, but an association was noted between RRP and ICI-related pneumonitis.Peer reviewe

Identification of CT radiomic features robust to acquisition and segmentation variations for improved prediction of radiotherapy-treated lung cancer patient recurrence.

peer reviewedThe primary objective of the present study was to identify a subset of radiomic features extracted from primary tumor imaged by computed tomography of early-stage non-small cell lung cancer patients, which remain unaffected by variations in segmentation quality and in computed tomography image acquisition protocol. The robustness of these features to segmentation variations was assessed by analyzing the correlation of feature values extracted from lesion volumes delineated by two annotators. The robustness to variations in acquisition protocol was evaluated by examining the correlation of features extracted from high-dose and low-dose computed tomography scans, both of which were acquired for each patient as part of the stereotactic body radiotherapy planning process. Among 106 radiomic features considered, 21 were identified as robust. An analysis including univariate and multivariate assessments was subsequently conducted to estimate the predictive performance of these robust features on the outcome of early-stage non-small cell lung cancer patients treated with stereotactic body radiation therapy. The univariate predictive analysis revealed that robust features demonstrated superior predictive potential compared to non-robust features. The multivariate analysis indicated that linear regression models built with robust features displayed greater generalization capabilities by outperforming other models in predicting the outcomes of an external validation dataset

Pilot Study: Evaluation of the use of personal medical images as a tool for therapeutic education in radiotherapy

Introduction Le cancer du poumon constitue un problème de Santé Publique du fait de sa fréquence et sa mortalité élevée. Habituellement traité par radiothérapie, combinée ou non avec de la chimiothérapie, le patient peut présenter des effets secondaires et un retentissement psycho-affectif important. Même s’il reçoit de l’information, l’utilisation des images médicales personnelles en éducation thérapeutique est peu étudiée. Cette communication présente l’évaluation de l’intervention selon Kirkpatrick. L’objectif principal concerne l’impact en terme d’anxiété et de dépression. Les objectifs secondaires concernent les autres niveaux : la satisfaction, le sentiment d’implication, les connaissances rapportées, la perception de se sentir préparé et l’adhésion thérapeutique. Méthode Une étude expérimentale de type « essai contrôlé randomisé » a été menée de façon mono-centrique afin de suivre des patients adultes, porteurs d’une pathologie cancéreuse traitée par radiothérapie thoracique, sur quatre périodes de temps. Le recrutement des patients s’est déroulé entre novembre 2019 et mars 2020. Le groupe contrôle a reçu oralement les informations données usuellement par le radiothérapeute. En plus de celles-ci, le groupe expérimental a bénéficié d’une intervention consistant en la visualisation de ses propres images de CT-Scanner combinées à la dosimétrie, via le programme informatique « Stone of Orthanc », accompagnée d’explications personnalisées du radiothérapeute selon un scénario standardisé. Le critère de jugement principal a été évalué par le questionnaire validé HADS « Hospital Anxiety And Depression Scale », complété par une échelle visuelle analogique de l’anxiété aux différents temps. Les critères secondaires ont été évalués via différents questionnaires créés spécifiquement pour cette étude. Résultats L’échantillon était composé d’un total de 45 patients. La crise du COVID-19 a prématurément interrompu la collecte des données. Au final, seules les données de quinze patients ont pu être utilisées. Bien que non-significatif, le groupe expérimental a montré un gain de connaissance plus important (47.5%) entre le T1 et le T3 que le groupe contrôle (35%) (p = 0.345), ainsi qu’une diminution plus importante des scores liés à l’anxiété (p = 0.577). Les résultats de l’EVA indiquent une tendance commune : le niveau d’anxiété augmente au T2 pour diminuer au T3 avec un niveau plus bas dans le groupe expérimental (0.65) que dans le groupe contrôle (1.00). Un paramètre présente une différence significative entre le T1 et le T3 : le score de dépression (p = 0.043) avec une diminution plus importante dans le groupe expérimental (-9.52%) que dans le groupe contrôle (aucune différence). Les résultats des autres paramètres sont restés similaires dans les deux groupes. Discussion Cette étude indique des résultats prometteurs pour l’utilisation de l’imagerie médicale au service de l’éducation thérapeutique du patient, notamment par l’individualisation des contenus. Les travaux futurs s’attacheront à confirmer ces constats sur une plus grande population

Commissioning Monte Carlo algorithm for robotic radiosurgery using cylindrical 3D-array with variable density inserts.

peer reviewed[en] INTRODUCTION: To commission the Monte Carlo (MC) algorithm based model of CyberKnife robotic stereotactic system (CK) and evaluate the feasibility of patient specific QA using the ArcCHECK cylindrical 3D-array (AC) with Multiplug inserts (MP). RESULTS: Four configurations were used for simple beam setup and two for patient QA, replacing water equivalent inserts by lung. For twelve collimators (5-60mm) in simple setup, mean (SD) differences between MC and RayTracing algorithm (RT) of the number of points failing the 3%/1mmgamma criteria were 1(1), 1(3), 1(2) and 1(2) for the four MP configurations. Tracking fiducials were placed within AC for patient QA. Single lung insert setup resulted in mean gamma-index 2%/2mm of 90.5% (range [74.3-95.9]) and 82.3% ([66.8-94.5]) for MC and RT respectively, while 93.5% ([86.8-98.2]) and 86.2% ([68.7-95.4]) in presence of largest inhomogeneities, showing significant differences (p<0.05). DISCUSSION: After evaluating the potential effects, 1.12g/cc PMMA and 0.09g/cc lung material assignment showed the best results. Overall, MC-based model showed superior results compared to RT for simple and patient specific testing, using a 2%/2mm criteria. Results are comparable with other reported commissionings for flattening filter free (FFF) delivery. Further improvement of MC calculation might be challenging as Multiplan has limited material library. CONCLUSIONS: The AC with Multiplug allowed for comprehensive commissioning of CyberKnife MC algorithm and is useful for patient specific QA for stereotactic body radiation therapy. MC calculation accuracy might be limited due to Multiplan's insufficient material library; still results are comparable with other reported commissioning measurements using FFF beams

Étude de faisabilité : l'utilisation de l'imagerie médicale en éducation thérapeutique en radiothérapie

Objectifs de l’étude Évaluer la faisabilité d’un essai contrôlé randomisé explorant l’utilisation de l’imagerie médicale en tant qu’intervention d’éducation thérapeutique (ETP) en radiothérapie externe. Matériel et méthodes Étude expérimentale de type « essai contrôlé randomisé » de faisabilité menée dans un seul centre, entre novembre 2019 et mars 2020, afin de suivre des patients adultes traités par irradiation thoracique. En plus des informations données usuellement, le groupe expérimental a bénéficié d’une intervention consistant en la visualisation de ses propres images médicales via le programme informatique open-source « Stone of Orthanc »

Prediction of GTV median dose differences eases Monte Carlo re-prescription in lung SBRT.

peer reviewed[en] BACKGROUND AND PURPOSE: The use of Monte Carlo (MC) dose calculation algorithm for lung patients treated with stereotactic body radiotherapy (SBRT) can be challenging. Prescription in low density media and time-consuming optimization conducted CyberKnife centers to propose an equivalent path length (EPL)-to-MC re-prescription method based on GTV median dose. Unknown at the time of planning, GTV D50% practical application remains difficult. The current study aims at creating a re-prescription predictive model in order to limit conflicting dose value during EPL optimization. MATERIAL AND METHODS: 129 patients planned with EPL algorithm were recalculated with MC. Relative GTV_D50% discrepancies were assessed and influencing parameters identified using wrapper feature selection. Based on best descriptive parameters, predictive nomogram was built from multivariate linear regression. EPL-to-MC OARs near max-dose discrepancies were reported. RESULTS: The differences in GTV_D50% (median 10%, SD: 9%) between MC and EPL were significantly (p < .001) impacted by the lesion's surface-to-volume ratio and the average relative electronic density of the GTV and the GTV's 15 mm shell. Built upon those parameters, a nomogram (R2 = 0.79, SE = 4%) predicting the GTV_D50% discrepancies was created. Furthermore EPL-to-MC OAR dose tolerance limit showed a strong linear correlation with coefficient range [0.84-0.99]. CONCLUSION: Good prediction on the required re-prescription can be achieved prior planning using our nomogram. Based on strong linear correlation between EPL and MC for OARs near max-dose, further restriction on dose constraints during the EPL optimization can be warranted. This a priori knowledge eases the re-prescription process in limiting conflicting dose value

Predictive clinical and dosimetric parameters for risk of relapse in early-stage non-small cell lung cancer treated by SBRT: A large single institution experience

peer reviewe

Stereotactic robotic body radiotherapy for patients with oligorecurrent pulmonary metastases.

BACKGROUND: Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free- (lung PFS/Di-PFS) and overall survival (OS). METHODS: Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk- and Cox regression. RESULTS: Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage. CONCLUSIONS: SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features