Guillaume Vogin

Local control and sequelae in localised Ewing tumours of the spine: a French retrospective study.

OBJECTIVES To evaluate both local outcome and sequelae of non-metastatic spinal Ewing tumours (EWT). PATIENTS AND METHODS A French cohort of patients ≤ 50years with localised spinal EWT treated between 1988 and 2009, was analysed in regard to tumour characteristics (e.g. volume, vertebral compartment, spinal cord compression, paraspinal soft tissue invasion), local treatment modalities (surgery (S) and margin quality, radiotherapy (RT) dose), response to treatment (e.g. histological response to neoadjuvant chemotherapy (CT)), tumour local control (LC) and sequelae. RESULTS Seventy-five patients treated in successive trials were evaluated for LC: SFOP-EW88 (n=14), SFOP-EW93 (n=17) and EuroEwing99 (n=44). Fifty-seven patients (79%) presented initial neurological compression and 69% had inaugural decompressive S. Local treatment modality was S+RT (n=50), RT alone (n=19) and S alone (n=6). Surgery was mainly intralesional (66%). Local recurrences had occurred in 19 patients (14 local, 5 loco-regional) with a median interval of 25 months (1-50). After a 7 year median follow-up (1-22 years), the 5-year LC, relapse-free survival (RFS) and overall survival (OS) reached 78.0% (95%CI: 62.6-84.6), 57.0% (95%CI: 45.2-68.9) and 70.0% (95%CI: 59.1-81.0), respectively. Vertebral compartment involved was the only prognostic factor (5-year LC rate 100% versus 71% for favourable and unfavourable compartment, p<0.03). Among 41 five-year survivors, we observed spinal curvature deformation (35%), growth retardation (28%), spinal reduction mobility (40%), spinal pain (25%) and neurological sequelae (32%) without any significant association with a particular local procedure. CONCLUSION RT is the backbone of a successful local treatment of spinal EWT. The place of S remains a pending question. Its actual benefit will likely evolve with new available RT techniques.

Tumor response assessment by MRI following stereotactic body radiation therapy for hepatocellular carcinoma

Background To evaluate the MRI features of a tumor response, local control, and predictive factors of local control after stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC). Methods Thirty-five consecutive patients with 48 HCCs who were treated by SBRT were included in this retrospective study. All patients provided written informed consent to be treated by SBRT, and prior to inclusion they authorized use of the treatment data for further studies. The assessment was made using MRI, with determination of local and hepatic responses according to Response Evaluation Criteria in Solid Tumors (RECIST) and modified RECIST (mRECIST) criteria during a two-year follow-up. Results The local response rate according to mRECIST was higher than with RECIST. A tumor diameter less than 20 mm at baseline was an independent predictive factor for RECIST and mRECIST responses, as was diffusion-weighted signal for RECIST. During follow-up, a tumor diameter of <20 mm (p = 0.034) and absence of a high intensity on T2-weighted (p = 0.006) and diffusion-weighted images (p = 0.039) were associated with a better response according to RECIST. Post-treatment changes include peritumoral ring-like enhanced changes with high intensity on T2-weighted images. Conclusions SBRT is a promising technique for the treatment of inoperable HCC. Post-treatment changes on MRI images can resemble tumor progression and as such must be adequately distinguished. The regression of tumorous enhancement is variable over time, although diffusion-weighted and T2-weighted intensities are predictive factors for tumor RECIST responses on subsequent MRIs. They hence provide a way to reliably predict treatment responses.

High dose rate brachytherapy with customized applicators for malignant facial skin lesions.

PURPOSE Brachytherapy is a well-known treatment in the management of skin tumors. For facial or scalp lesions, applicators have been developed to deliver non-invasive treatment. We present cases treated with customized applicators with high dose rate system. MATERIAL AND METHODS Patients with poor performance status treated for malignant skin lesions of the scalp or the facial skin between 2011 and 2014 were studied. Afterloading devices were chosen between Freiburg(®) Flap, silicone-mold or wax applicators. The clinical target volume (CTV) was created by adding margins to lesions (10mm to 20mm). The dose schedules were 25Gy in five fractions for postoperative lesions, 30Gy in six fractions for exclusive treatments and a single session of 8Gy could be considered for palliative treatments. RESULTS In 30 months, 11 patients received a treatment for a total of 12 lesions. The median age was 80 years. The median follow-up was 17 months and the 2-year local control rate was 91%. The mean CTV surface was 41.1cm(2) with a mean thickness of 6.1mm. We conceived three wax applicators, used our silicone-mold eight times and the Freiburg(®) Flap one time. We observed only low-grade radiodermitis (grade I: 50%, grade II: 33%), and no high-grade skin toxicity. CONCLUSION High dose rate brachytherapy with customized applicators for facial skin and scalp lesions is efficient and safe. It is a good modality to treat complex lesions in patients unfit for invasive treatment.

Radiothérapie adaptative des cancers ORL : un outil permettant d’identifier les patients nécessitant une adaptation de leur traitement

PURPOSE The purpose of this work was to implement a simple dosimetric alert tool in a retrospective study for six patients suffering from head and neck cancer to detect when a patient might require an adaptive radiotherapy. MATERIALS AND METHODS The dosimetric tool generates a 3D cartography of two dosimetric complementary information: a dose variation tolerance map and a dose differential map. The tolerance map is calculated on the initial scanner (CTinit) using the planned dose distribution. It shows for each voxel of each delineated volume the availability for local dose variations during the course of radiotherapy without exceeding the dose threshold. The differential dose map is generated on the tomographic image CBCT (CBCTtreatment). It shows dose variations between the planned and the actual delivered dose distribution for each voxel. By comparing both maps, when a voxel presents a value superior to the corresponding dose variation tolerance, an alert is generated and the anatomical areas concerned are visually indicated to the physician. RESULTS The application of the dosimetric tool on six patients with head and neck cancers reveals the ability of the tool to detect cases requiring a new treatment plan. Two patients whose the tumour shrinkage produced an increase of the delivered dose to the spinal cord beyond 45 Gy have been detected. CONCLUSION The development of the dosimetric tool allows the automatic detection, with no delineation needs, of patients suffering from head and neck cancers requiring an adaptive strategy.

Sarcomes d’Ewing localisés du rachis chez l’enfant : étude préliminaire d’escalade de dose comparant les techniques innovantes

PURPOSE Although radiosensitive, spinal locations of Ewings sarcomas are challenging for the radiation oncologist due to poor radiation tolerance of the spinal cord. However, some favorable anatomical compartments - that may represent more than 20% - were associated with a better outcome and could benefit from a radiation dose escalation using the most recent radiation therapy techniques. MATERIALS AND METHODS We performed a dose escalation study on one patient, declined in two scenarios: (1) a tumour located within a single vertebral body and (2) a locally advanced disease involving the vertebral foramen and paraspinal soft tissues. Five dose-levels are proposed: 44.8Gy, 54.4Gy, 59.2Gy, 65.6Gy and 70.4Gy (1.6Gy per session, 8Gy per week). The 3D-conformational technique is compared with static intensity modulated radiation therapy (IMRT), helical tomotherapy, volumetric modulated arc therapy (VMAT), stereotactic body robotic radiation therapy (SBRT) and protontherapy (passive scattering). Two constraints had to be respected in order to skip to the next level: the planned target volume (PTV) coverage must exceed 95% and the D(2%) on the spinal cord shall not exceed a given constraint set at 50Gy in case 1 and 44Gy in case 2 due to initial neurological sufferance. RESULTS Only protontherapy, SBRT, helical tomotherapy and VMAT appear able to reach the last dose level while respecting the constraints in case 1. On the other hand, only helical tomotherapy seems capable of reaching 59.2Gy on the PTV in case 2. CONCLUSION With the most recent radiation therapy techniques, it becomes possible to deliver up to 70.4Gy in a favorable compartment in this sham patient. Unfavorable compartments can receive up to 59.2Gy. Definitive radiation therapy may be an interesting local treatment option to be validated in an early phase trial.

Time interval between surgery and start of adjuvant radiotherapy in patients with soft tissue sarcoma: A retrospective analysis of 1131 cases from the French Sarcoma Group

PURPOSE The aim of this study was to evaluate the impact of the time interval (TI) between surgery and adjuvant radiotherapy (RT) in soft tissue sarcoma (STS). METHODS AND MATERIALS Data from 1131 patients treated between 1990 and 2014 were retrospectively reviewed. Inclusion criteria were: limb or superficial trunk wall STS (R0 or R1 resection) and adjuvant RT. The impact of TI on 10-year local relapse-free survival (LRFS) and 10-year overall survival (OS) was analyzed using a Log-rank test and then Cox Model. RESULTS The median TI was 82days (range, 18-346). With a median follow-up of 235months (range, 2-296months), the 10-year LRFS was 57.5% (±2%) and the 10-year OS was 64.2% (±2%). With a TI of 19-39days, 40-79days, 80-119days, and ⩾120days, 10-year LRFSs were 65.3%, 55.5%, 56.9% and 61.2% (p=0.465), and 10-year OSs were 72.8%, 60.7%, 66.4% and 62.1% (p=0.347), respectively. After adjustment for the factors significantly (p⩽0.05) associated with LRFS and OS, TI did not alter LRFS (p=0.182) either OS (p=0.335). CONCLUSIONS In this retrospective STS database study, the TI between surgery and start of adjuvant RT did not seem to affect outcomes.

Investigation of ectopic recurrent skull base and cervical chordomas: The Institut Curie's proton therapy center experience

Cervical and skull base chordomas may relapse locally, marginally, or in ectopic sites (ie, surgical pathway, lymph nodes, prevertebral space, subdural space, or distant organs).

A retrospective cohort study to assess adjuvant concurrent chemoradiation (CCRT) compared to adjuvant radiation therapy (RT) in the treatment of grade 2 and 3 extremity soft tissue sarcomas

PURPOSE To evaluate the efficacy and tolerance of adjuvant concurrent chemoradiation (CCRT) as treatment of grade 2 and 3 (G2-3) localized extremity soft tissue sarcomas (STS) by comparing CCRT with standard adjuvant radiation therapy (RT). PATIENTS AND METHODS This monocentric retrospective study included non-pediatric patients (>16years) treated by adjuvant RT with or without chemotherapy (CT) after conservative resection of non-recurrent G2-3 extremity STS. RESULTS A total of 80 patients were treated between 1990 and 2012: 51 by RT and 29 by CCRT. Of the 29 CCRT patients, 25 received doxorubicin monotherapy (75mg/m2/3weeks). The CCRT group contained a greater proportion of grade 3 extremity STS (p<0.001). Median follow up was 68months (9-284). Multivariate analysis revealed greater local control in the CCRT group (1 local recurrence vs 8 in the RT group; HR=0.082, 95% CI 0.011-0.321) and incomplete resection as the major risk factor of local recurrence (HR=25.2, 95% CI 4.767-133.226). The two groups exhibited no differences in distant failure-free survival (HR=1.469, 95% CI 0.668-3.228), disease-free survival (HR=1.096, 95% CI 0.519-2.315) or overall survival (HR=1.378, 95% CI 0.498-3.814). Grade 3 was an adverse prognostic factor for overall survival (HR=3.11, 95% CI 1.04-9.32). Our analyses also revealed that CCRT tended to increase the risk of both grade ≥3 acute dermatitis (14 events vs 6 in the RT group; OR=6.99, 95% CI 2.28-21.47) and grade ≥2 late toxicity (6 events vs 3 in the RT group; p=0.0572). CONCLUSION CCRT could improve local control as part of a limb-preservation strategy. However, with a limited number of patients, CCRT showed no improvement in either distant control or survival and increased toxicity.

Contraintes de doses aux organes à risque en radiothérapie conformationnelle et stéréotaxique : intestin grêle et duodénum

Radiotherapy of abdominopelvic primary or secondary lesions in conformational or stereotactic techniques is in full development. The small bowel is highly sensitive to irradiation and is the main organ at risk limiting prescription doses. This literature review aims to define the dose constraints to the small bowel and the duodenum in conformational and stereotactic body radiotherapy. The small bowel including the duodenum, jejunum and ileum is delineated on the simulation scanner. The radio-induced intestinal toxicities are acute related to the cellular depopulation of the intestinal mucosa, and late of more complex pathophysiology associating depletion in stem cells, microangiopathy, chronic inflammation and fibrosis. The main predictive factor of intestinal toxicity is the dose-volume ratio. In conformational radiotherapy, the dose constraints to the duodenum are: V25Gy<45% and V35Gy<20%. The jejunum and ileum dose constraints are for delineation by intestinal loop or peritoneal cavity respectively: V15Gy<275mL or V15Gy<830mL and V45Gy<150mL. In stereotactic body radiotherapy, small bowel dose constraints depend on fractionation and are defined on a small volume and on a maximum dose at one point. Intestinal toxicity is also dependent on factors intrinsic to the patient and radiosensitizers such as targeted therapies or chemotherapies. With the development of new techniques allowing dose escalation on the tumour and the development of inverse planning, the definition of dose constraints to the small bowel is essential for current practice.

NHL-ChirEx: An interprofessional cross-border education initiative in the Greater Region with a focus on radiation morbidity and patient safety

NHL-ChirEx is an interprofessional cross-border education project that addresses the potential excess of radiation induced morbidity throughout the radiation planning and treatment process. NHL-ChirEx is supported by ESTRO and the University of the Greater Region and has been recently approved and funded under INTERREG VA Programme.