A Single-center Experience of Radiotherapy in Pediatric Ewing Sarcoma/Primitive Neuroectodermal Tumor of the Chest Wall.

AIM: To evaluate the treatment results, prognostic parameters, and treatment-related toxicity in patients with Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the chest wall who underwent surgery, chemotherapy, and radiotherapy (RT) in a tertiary referral center. METHODS: The data of 24 patients under 18 years of age with a histologic diagnosis of ES/PNET in the chest wall that received RT in our department between February 2003 and July 2020 were retrospectively evaluated. RT was applied to the primary site±whole involved chest wall and to the whole lung in patients with lung metastasis. RESULTS: The median age was 8.5 years (range: 1.5 to 17 y), 15 (63%) patients were female and 9 were male (37%). The tumor localization was extrathoracic in 18 (75%) and intrathoracic in 6 (25%) patients. Mediastinal lymph node and distant metastasis (DM) was present in 5 (21%) and 4 (16%) cases at diagnosis, respectively. The median follow-up after RT was 47 months (range: 11 to 162 mo). The 2-year and 5-year overall survival, event-free survival, local recurrence-free survival, and pleural recurrence-free survival were 83% and 48%, 48% and 42%, 74% and 48%, and 61% and 52%, respectively. The overall local control rate was 83% and the pleural control rate was 67%. RT was well tolerated, with 1 case of grade 3 acute dermatitis and 1 case of grade 3 subacute radiation pneumonitis. Late toxicity was observed in 3 (13%) cases. CONCLUSION: Long-term survival can be achieved with extended-field RT even in patients with ES/PNET of the chest wall with DM. The low toxicity rates allow us to draw the conclusion that RT with modern techniques is an effective and safe treatment modality for these patients.

Intraoperative radiation therapy for pediatric sarcomas and other solid tumors.

PURPOSE: To evaluate local failure (LF) and toxicity after intraoperative radiation therapy (IORT) in pediatric solid tumors (ST). METHODS: A single-institution retrospective study of 96 pediatric patients (108 applications) with ST treated from 1995 to 2022 with IORT. LF was calculated via cumulative incidence function and overall survival (OS) by Kaplan-Meier method, both from the day of surgery. RESULTS: Median age at time of IORT was 8 years (range: 0.8-20.9 years). Median follow-up for all patients and surviving patients was 16 months and 3 years, respectively. The most common histologies included rhabdomyosarcoma (n = 42), Ewing sarcoma (n = 10), and Wilms tumor (n = 9). Most (95%) received chemotherapy, 37% had prior external beam radiation therapy to the site of IORT, and 46% had a prior surgery for tumor resection. About half (54%) were treated with upfront IORT to the primary tumor due to difficult circumstances such as very young age or challenging anatomy. The median IORT dose was 12 Gy (range: 4-18 Gy), and median area treated was 24 cm2 (range: 2-198 cm2). The cumulative incidence of LF was 17% at 2 years and 23% at 5 years. Toxicity from IORT was reasonable, with postoperative complications likely related to IORT seen in 15 (16%) patients. CONCLUSION: Our study represents the largest and most recent analysis of efficacy and safety of IORT in pediatric patients with ST. Less than one quarter of all patients failed locally with acceptable toxicities. Overall, IORT is an effective and safe technique to achieve local control in patients with challenging circumstances.

Extracorporeal irradiation in malignant bone tumors: Single institution experience and review of literature.

In the last couple of decades, the management of malignant bone tumor (MBT) has seen a sea change. With the advent in surgical technics, radiation therapy, and chemotherapy, it has moved from disabling amputation to limb salvage surgery. Extracorporeal irradiation (ECI) and re-implantation of resected bone is a useful method of limb salvage of MBTs. In our study, we analyzed and presented the results of 8 cases of MBTs treated with this modality. Between 2014 and 2017, 8 patients with primary MBT were enrolled for ECI technique who are meeting the eligibility criteria. Before taking the patient for ECI treatment, a multispecialty tumor board discussion was done for each patient. All of them received neo-adjuvant and adjuvant chemotherapy except the patients with histology of giant cell tumor. Following neoadjuvant chemotherapy bone excision surgery was performed, and the resected bone was taken for ECI with the dose of 50 Gray in a single fraction. After ECI, bone segment was re-implanted at osteotomy site in the same setting. After completion of adjuvant chemotherapy, the patients were then followed up for any sequelae, local and systemic control, ambulation, and functional outcome. Out of 8 patients, there were 5 males and 3 females with mean age of 22 (range 13-36). The involved bone was the tibia in 6 patients, ischium in 1 patient, and femur in 1 patient. Histopathologically, the malignancies included 3 osteosarcoma, 3 Giant cell tumor, 1 Ewing's sarcoma and 1 chondrosarcoma. At median follow-up of 12 months (range 6-26 months), local control rate was 87.5% and systemic control rate was 75%. Perioperative ECI and re-implantation is a useful, convenient, and inexpensive technique. The overall treatment time is reduced. The patient's own bone fits perfectly to the resection site with reduced risk of graft site infection. The risk of local recurrence due to tumor re-implantation is negligible with tumoricidal radiation doses of ECI, and it is usually associated with manageable sequelae. Recurrence rates are acceptable and salvageable with surgery.

Sarcoma de Ewing multifocal: presentación de un caso pediátrico / Multifocal Ewing sarcoma: presentation of a pediatric case / Sarcoma de Ewing Multifocal: apresentação de um caso pediátrico

Introducción: el Sarcoma de Ewing es una neoplasia maligna de origen mesenquimático. Al momento del diagnóstico el 75% se presentan en forma localizada. Objetivo: comunicar un caso que por su presentación multifocal, generó dificultades diagnósticas. Caso clínico: niña de 6 años. Consulta por traumatismo de mano derecha tras caída de su altura 24 horas previas, constatándose en mano y puño derecho edema, calor y eritema, movilidad conservada. No fiebre. Radiografía: aumento del diámetro del tercer metacarpiano, imagen esmerilada, no trazos de fracturas. Ingresa con planteo de celulitis. Anemia leve microcítica, hipocrómica. Proteína C reactiva 82 mg/l. Recibe clindamicina intravenosa 72 horas, completa 14 días vía oral. Persistencia de alteraciones en puño y mano derecha, agrega tumoración de raíz nasal con desviación del eje, indolora. Fosfatasa alcalina, lactato deshidrogenasa, fosfatemia, calcemia normales. Resonancia magnética: alteración morfoestructural de radio, olecranon y tercer metacarpiano, fractura de olecranon y radio, reacción perióstica. Pet-Scan: lesión extensa ósea en macizo facial, tibias, cúbitos, humero derecho y clavícula. Biopsia 3er metacarpiano: tumor de células pequeñas, redondas azules, CD99 y vimentina positivo. Comienza poliquimioterapia y radioterapia sin complicaciones. Conclusiones: es frecuente que las manifestaciones clínicas iniciales sean confundidas con entidades más frecuentes, como post-traumáticas y/o inflamatorias, tal como ocurrió en este caso. Posteriormente, la aparición de nuevas lesiones y compromiso del estado general orientó el abordaje diagnóstico de la patología tumoral. La confirmación exige el estudio anatomopatológico con estudio inmunohistoquímico. La presencia de metástasis óseas constituye un factor de mal pronóstico y dificulta el abordaje terapéutico.

Introduction: Ewing's sarcoma is a malignant neoplasm of mesenchymal origin. At the time of diagnosis 75% of the cases are localized. Objective: to report a case that, due to its multifocal presentation, generated diagnostic difficulties. Clinical case: 6-year-old girl. She consulted for right hand trauma after a fall from her height 24 hours earlier, with edema, warmth and erythema in the right hand and fist, with preserved mobility. No fever. X-ray: increase in the diameter of the 3rd metacarpal, frosted image, no traces of fractures. Admitted with cellulitis. Mild microcytic anemia, hypochromic. C-reactive protein 82mg/l. Receives intravenous clindamycin 72 hours, completes 14 days orally. Persistence of alterations in fist and right hand, adds tumor of nasal root with deviation of the axis, painless. Alkaline phosphatase, lactate dehydrogenase, phosphatemia, normal calcemia. MRI: morphostructural alteration of radius, olecranon and 3rd metacarpal, fracture of olecranon and radius, periosteal reaction. Pet-Scan: extensive bone lesion in facial mass, tibiae, ulnae, right humerus and clavicle. Biopsy 3rd metacarpal: small cell tumor, blue round, CD 99 and vimentin positive. Polychemotherapy and radiotherapy were started without complications. Conclusions: it is frequent that the initial clinical manifestations are confused with more frequent entities, such as post-traumatic and/or inflammatory, as occurred in this case. Subsequently, the appearance of new lesions and compromise of the general condition guided the diagnostic approach of the tumor pathology. Confirmation requires anatomopathological study with immunohistochemical study. The presence of bone metastases constitutes a poor prognostic factor and hinders the therapeutic approach.

Introdução: O sarcoma de Ewing é um neoplasma maligno de origem mesenquimatosa. No momento do diagnóstico, 75% dos casos são localizados. Objetivo: Relatar um caso que, devido a sua apresentação multifocal, causou dificuldades diagnósticas. Caso clínico: Menina de 6 anos. Ela consultou por traumatismo à mão direita após cair de sua altura 24 horas antes, com edema, calor e eritema na mão direita e punho, com mobilidade preservada. Sem febre. Raio-X: aumento do diâmetro do 3º metacarpo, imagem fosca, sem vestígios de fraturas. Admitido com a sugestão de celulite. Anemia microcítica leve, hipocrómica. Proteína C reativa 82mg/l. Recebe clindamicina intravenosa por 72 horas, completa 14 dias por via oral. Persistência de alterações no punho e mão direita, tumor indolor da raiz nasal com desvio do eixo. Fosfatase alcalina, desidrogenase láctica, fosfataemia, calcemia normal. IRM: alteração morfo-estrutural do rádio, olecrânio e 3º metacarpo, fratura do olecrânio e do rádio, reação periosteal. Pet-Scan: extensa lesão óssea na massa facial, tíbia, ulnae, úmero direito e clavícula. Biópsia do 3º metacarpo: tumor de pequenas células, redondo azul, CD 99 e vimentina positiva. Ela iniciou a poli-quimioterapia e radioterapia sem complicações. Conclusões: É comum que as manifestações clínicas iniciais sejam confundidas com entidades mais freqüentes, tais como pós-traumáticas e/ou inflamatórias, como ocorreu neste caso. Posteriormente, o aparecimento de novas lesões e o envolvimento do quadro geral levaram a uma abordagem diagnóstica da patologia tumoral. A confirmação requer um estudo anatomopatológico com estudo imuno-histoquímico. A presença de metástases ósseas é um fator de mau prognóstico e dificulta a abordagem terapêutica.

Cell cycle arrest and apoptosis are early events in radiosensitization of EWS::FLI1+ Ewing sarcoma cells by Mithramycin A.

PURPOSE: The oncogenic fusion protein EWS::FLI1 is an attractive therapeutic target in Ewing sarcoma (ES). Mithramycin A (MithA) is a potent and specific inhibitor of EWS::FLI1 that can selectively radiosensitize ES cells through transcriptional inhibition of DNA double-strand break (DSB) repair. Here, we evaluate temporal changes in cell cycle progression and apoptosis in ES cells treated with MithA and/or ionizing radiation (RTx), testing the hypothesis that combining MithA with ionizing radiation would synergistically impair cell cycle progression and enhance apoptotic elimination to a greater extent than either agent alone. MATERIALS AND METHODS: Four EWS::FLI1+ ES cell lines TC-71, RD-ES, SK-ES-1, and A673, and one EWS::ERG cell line (CHLA-25) were exposed to 10nM MithA or vehicle and followed 24 h later by exposure to 2 Gy x-radiation or sham irradiation. Reactive oxygen species (ROS) activity was evaluated by cytometric assay, and assay of antioxidant gene expression by RT-qPCR. Cell cycle changes were evaluated by flow cytometry of nuclei stained with propidium iodide. Apoptosis was assessed by cytometric assessment of Caspase-3/7 activity and by immunoblotting of PARP-1 cleavage. Radiosensitization was evaluated by clonogenic survival assay. Proliferation (EdU) and apoptosis (TUNEL) were evaluated in SK-ES-1 xenograft tumors following pretreatment with 1 mg/kg MithA, followed 24 h later by a single 4 Gy fraction of x-radiation. RESULTS: MithA-treated cells showed reduced levels of ROS, and were associated with increased expression of antioxidant genes SOD1, SOD2, and CAT. It nonetheless induced persistent G0/G1 arrest and a progressive increase of the sub-G1 fraction, suggesting apoptotic degeneration. In vitro assays of Caspase-3/7 activity and immunoblotting of Caspase-3/7 dependent cleavage of PARP-1 indicated that apoptosis began as early as 24 h after MithA exposure, reducing clonogenic survival. Tumors from xenograft mice treated with either radiation alone, or in combination with MithA showed a significant reduction of tumor cell proliferation, while apoptosis was significantly increased in the group receiving the combination of MithA and RTx. CONCLUSIONS: Taken together, our data show that the anti-proliferative and cytotoxic effects of MithA are the prominent components of radiosensitization of EWS::FLI1+ ES, rather than the result of acutely enhanced ROS levels.

Equivocal end-of-therapy imaging findings do not predict a higher risk of local relapse after definitive radiotherapy in pediatric Ewing sarcoma and rhabdomyosarcoma.

BACKGROUND: Posttherapy imaging studies can provide reassurance or induce anxiety regarding risk of recurrence for patients and their families. In some cases, it is difficult to determine if imaging findings represent posttreatment changes or residual disease. Equivocal radiographic findings can occur due to therapy-related inflammation or residual, inactive soft tissue masses, but it is unknown if such findings indicate an increased likelihood of local recurrence. The aim of this study was to assess the value of initial posttherapy scans for predicting local relapse in patients with Ewing sarcoma (EWS) or rhabdomyosarcoma (RMS) who received radiotherapy (RT) for local control. These findings are critical to inform clinicians' surveillance recommendations and ability to accurately counsel patients and their families. PROCEDURE: The primary endpoint was time to local progression (LP). Patients were classified as having posttherapy scans that were "positive" (residual disease within the RT field), "negative" (no evidence of residual disease within the RT field), or "equivocal" (no determination could be made). The value of initial posttreatment scans for predicting LP was assessed using positive predictive value (PPV) and negative predictive value (NPV). RESULTS: Negative imaging findings (n = 51) had an NPV of 88%, and positive imaging findings (n = 1) had a PPV of 100%. When equivocal findings (n = 16) were categorized with negative results (i.e., positive vs. equivocal/negative), the NPV was 90%. When equivocal findings were categorized with positive results (equivocal/positive vs. negative), the PPV was 12%. CONCLUSION: Equivocal findings within the RT field on end-of-therapy imaging studies indicate no higher risk of local recurrence than negative findings. These results may contribute to appropriate surveillance schedules and accurate counseling of patients with RMS and EWS who have received RT for local control.

Is High-dose Radiation Therapy Associated With Early Revision Due to Aseptic Loosening in Patients With a Sarcoma of the Lower Extremities Reconstructed With a Cemented Endoprosthesis?

BACKGROUND: The durability of endoprostheses after limb salvage surgery is influenced by surgical factors (resection length, implant location, and residual bone quality), implant design (modular versus custom design, rotating versus fixed hinge, coating, collars, and the use of cross pins), and host factors (patient's immune status, activity levels, and age). In general, radiation therapy increases the risk of fractures, infection, delayed wound healing, and impaired osseointegration. Several studies have shown exposure to radiation to be associated with higher endoprosthesis revision rates and higher periprosthetic infection rates, but results are inconsistent. Although radiation therapy is not routinely used in the treatment of many bone sarcomas in current practice, it is still used in high doses after resection and prosthetic reconstruction in patients who have Ewing sarcoma with close or positive margins and in patients with soft tissue sarcoma. It is also used in varying doses after prosthetic reconstruction in patients with myeloma or bone metastasis after resection of periarticular destructive tumors. These patients may be at an increased risk of complications due to their radiation exposure, but this is a difficult question to study given the rarity of these diagnoses and poor overall survival of these patients. We therefore leveraged a large, longitudinally collected, 40-year endoprosthesis database that included patients who received radiation to the extremity for many bone and soft tissue sarcomas to investigate the association between preoperative or postoperative radiation therapy and endoprosthesis survival. QUESTIONS/PURPOSES: (1) Is receiving preoperative or postoperative radiation therapy in low or high doses for the treatment of bone or soft tissue malignancy of the lower extremities associated with decreased implant survivorship free from amputation or revision due to any cause? (2) Is receiving preoperative or postoperative radiation therapy in low or high doses for the treatment of bone or soft tissue malignancy of the lower extremities associated with decreased implant survivorship free from revision specifically due to aseptic loosening? (3) Is receiving preoperative or postoperative radiation therapy for the treatment of Ewing sarcoma of the femur specifically associated with decreased implant survivorship free from revision specifically due to aseptic loosening? METHODS: This was a retrospective, comparative study using our institution's database of 822 endoprostheses. Between 1980 and 2019, we treated 541 patients with primary cemented endoprostheses of the extremities. Of those patients, 8% (45 of 541) were excluded due to unknown radiation status, 3% (17 of 541) because of prior failed allograft, 15% (83 of 541) due to metastatic disease from a carcinoma, 1% (6 of 541) due to a nononcologic diagnosis, 4% (20 of 541) due to benign tumor diagnosis, 16% (87 of 541) due to upper extremity tumor location, 9% (49 of 541) due to not receiving chemotherapy, and 3% (14 of 541) due to expandable prostheses. Of the remaining 220 patients, 6% (13) were considered missing because they did not have 2 years of follow-up and did not reach a study endpoint. No patients had surgery within the last 2 years of the study end date. In all, 207 patients met inclusion criteria and were eligible for analysis. Patients who had received radiation to the lower extremities at any point in their treatment course were included in the radiation group and were compared with patients who did not receive radiation. For patients where radiation dose was available, the radiation group was subdivided into a low-dose (≤ 3000 cGy) and high-dose (> 3000 cGy) group. Revision surgery was defined as any surgery necessitating removal or replacement of the tibial or femoral stem. The complications necessitating revision or amputation were poor wound healing, aseptic loosening, implant breakage, deep infection, and tumor progression. The primary outcome of interest was implant survival free from revision or amputation due to any cause. The secondary outcome of interest was implant survival free from revision or amputation specifically due to aseptic loosening. The Kaplan-Meier survivorship curves were generated with implant survival free from revision or amputation as the endpoint and patient death as a competing risk. A log-rank test was used to identify differences in survivorship between the patients who received radiation and those who did not. Multivariate regression was used to identify factors associated with decreased implant survival. An odds ratio was used to determine relative effect size among the factors associated with decreased implant survival. RESULTS: The mean implant survival time for patients who did not receive radiation was 18.3 years (95% confidence interval [CI] 15.4 to 21.3) whereas the mean implant survival time for patients who received low- and high-dose radiation were 19.1 years (95% CI 14.5 to 23.7; p = 0.59) and 13.8 years (95% CI 8.2 to 19.5; p = 0.65), respectively. The mean implant survival free from revision for aseptic loosening for patients who did not receive radiation was 27.1 years (95% CI 24.1 to 30.1) whereas the mean implant survival for patients who received low- and high-dose radiation were 24.1 years (95% CI 19.1 to 29.1; p = 0.34) and 16.4 years (95% CI 10.6 to 22.2; p = 0.01), respectively. Patients who received high-dose radiation had decreased 5-year implant survivorship free from amputation or revision due to aseptic loosening (73% [95% CI 44% to 89%]) compared with patients who did not receive radiation (95% [95% CI 90% to 99%]; p = 0.01). For patients treated for Ewing sarcoma of the femur, the 5-year implant survival free from amputation or revision due to aseptic loosening for patients who did not receive radiation (100% [95% CI 100% to 100%]) was no different compared with patients who received radiation (71% [95% CI 35% to 90%]; p = 0.56). CONCLUSION: The results of this study may apply to scenarios where radiation is used, such as Ewing sarcoma with positive margins or local recurrence and after prosthetic reconstruction in patients with myeloma or bone metastasis after resection of periarticular destructive tumors. Surgeons may consider closer monitoring for early clinical and radiographic signs of aseptic loosening in patients who received high-dose radiation. These patients may also benefit from constructs that have increased resistance to aseptic loosening such as cross-pin or side plate fixation. The association between radiation and aseptic loosening should be further studied with larger studies with homogeneity in tumor diagnosis and prosthesis. The dose-dependent relationship between radiation and bone-related complications may also benefit from controlled, laboratory-based biomechanical studies. LEVEL OF EVIDENCE: Level III, therapeutic study.

Analysis of Local Control Outcomes and Clinical Prognostic Factors in Localized Pelvic Ewing Sarcoma Patients Treated With Radiation Therapy: A Report From the Children's Oncology Group.

PURPOSE: To identify potential clinical prognostic factors associated with a higher risk of local recurrence in patients with localized pelvic Ewing sarcoma treated with radiation therapy. METHODS AND MATERIALS: Data for 101 patients treated with definitive radiation therapy (RT) or both surgery and radiation (S + RT) to primary pelvic tumors on INT-0091, INT-0154, and AEWS0031 were analyzed. Imaging data for patients who did not receive radiation were not available for central review; therefore, patients with surgery alone were not included. Cumulative incidence rates for local failure at 5 years from time of local control were calculated accounting for competing risks. RESULTS: The most common pelvic subsite was sacrum (44.6%). RT was used in 68% of patients and S + RT in 32%. The local failure rate was 25.0% for RT and 6.3% for S + RT (P = .046). There was no statistically significant difference in local control modality by tumor characteristics. Tumors originating in the ischiopubic-acetabulum region were associated with the highest local failure incidence, 37.5% (P = .02, vs sacrum and iliac/buttock tumors), particularly those treated with RT (50.0%, P = .06). A higher incidence of local failure was seen with each additional 100 mL of tumor at diagnosis (P = .04). Multivariable analysis demonstrated RT alone (hazard ratio [HR], 5.1; P = .04), tumor subsite (particularly ischiopubic-acetabulum tumors; HR 4.6; P = .02), and increasing volume per 100 mL (HR, 1.2; P = .01) were associated with a higher incidence of local recurrence. CONCLUSIONS: Combination surgery and RT is associated with improved local control in patients with pelvic Ewing sarcoma compared with definitive RT. Tumors involving the ischiopubic-acetabulum region and increasing tumor volume at diagnosis are associated with inferior local control. Tumor characteristics did not correlate with choice of local therapy modality suggesting an opportunity to develop best local therapy practices guidelines for future studies based on tumor features.

Quality-of-life evaluations in children and adolescents with Ewing sarcoma treated with pencil-beam-scanning proton therapy.

BACKGROUND: With improved survival rates for children with cancer, quality-of-life (QoL) issues have increasingly become the focus of attention. We report the QoL of children with Ewing sarcoma (EWS) treated with pencil-beam-scanning proton therapy (PT). METHODS: A PEDQOL (QoL questionnaire for children 4-18 years) self/proxy questionnaire was used to prospectively assess the QoL of 23 children <18 years with EWS treated with PT. This questionnaire evaluates eight different domains. Children (self-rating) and parents (proxy-rating) filled out the questionnaire at the start of PT (E1), 2 months after treatment (E2), and thereafter once yearly (E≥3). RESULTS: Compared with healthy controls, parents rated the QoL of their children at E1 significantly worse in all but two (cognition and social functioning-family) domains. At E4, significant differences between the two groups only remained in three of eight domains. At E1, children self-rated their QoL significantly worse in the domain Physical functioning (p = .004) and significantly better in the domain Body image (p = .044) compared to healthy controls, whereas no significant differences were observed at E4. For the longitudinal comparison E1 versus E4, according to parents, Emotional functioning, Cognition and Social functioning-peers were slightly decreased 2 years after PT. The children rated Emotional functioning and Body image poorly 2 years after PT. CONCLUSIONS: Children with EWS usually recovered seemingly well to normal QoL levels 2 years after the end of PT. They tended to rate their QoL substantially higher than their parents. However, in the longitudinal analysis at 2 years, children rated their Emotional functioning and Body image scores poorly.

High-dose chemotherapy followed by whole lung irradiation in pulmonary relapse Ewing's sarcomas: a retrospective multicenter study.

OBJECTIVE: Regarding the efficiency of Bu-Mel-based high-dose-chemotherapy (Bu-Mel-HDCT) and whole lung irradiation (WLI), the objective was to evaluate the efficiency and safety of this salvage sequence in Ewing sarcoma (ES) lung relapses. METHODS: All eligible pediatric ES patients (1991-2020) identified in SFCE departments were retrospectively reviewed. Seven patients were (1) diagnosed with a pulmonary relapse, isolated or not, (2) naïve from both HCDT and WLI (3) treated by the salvage sequence of conventional chemotherapy, Bu-Mel-HDCT and WLI. The main endpoint was OS evaluation. WLI toxicities were scored using CTC-V5. RESULTS: With a 13 years median follow-up (FU), 5/7 patients are alive and in complete remission. 10y-EFS is 71.4%. Three patients experienced transitory radio-induced pneumopathy (RIP). A patient developed RIP (gr.3) and finally progressive lung fibrosis leading to death. CONCLUSION: This study reports seven ES patients treated for lung metastatic relapses, using an aggressive strategy, with favorable survival long-term results which should be balanced with the risk of lung toxicity. ADVANCES IN KNOWLEDGE: The approach of surgery, Bu-Mel HDCT followed by WLI can be discussed in selected ES patients with lung relapse, naive from HDCT or WLI, providing an optimal chemosensitivity. A special vigilance is necessary regarding the incidence rate of lung toxicity which can be mitigated by limiting the radiotherapy dose, and observing optimal timing of radiotherapy after HDCT.

Radiation Therapy Dose Escalation in Unresectable Ewing Sarcoma: Final Results of a Phase 3 Randomized Controlled Trial.

PURPOSE: Our aim was to assess the effect of radiation therapy (RT) dose escalation on outcomes in surgically unresectable Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET). METHODS AND MATERIALS: Patients with nonmetastatic unresectable ES/PNET (excluding intracranial/chest wall) receiving vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide chemotherapy, planned for definitive RT, were accrued in this single-institution, open-label, phase 3 randomized controlled trial. Randomization was between standard dose RT (SDRT; 55.8 Gy/31 fractions/5 days a week) versus escalated dose RT (EDRT; 70.2 Gy/39 fractions/5 days a week) with a primary objective of improving local control (LC) by 17% (65%-82%). Secondary outcomes included disease-free survival (DFS), overall survival (OS), and functional outcomes by Musculoskeletal Tumor Society score. RESULTS: Between April 2005 and December 2015, 95 patients (SDRT 47 and EDRT 48) with a median age of 17 years (interquartile range, 13-23 years) were accrued. The majority of patients were male (59%). Pelvis was the most common site of primary disease (n = 60; 63%). The median largest tumor dimension (9.7 cm) and the median maximum standardized uptake value (8.2) on pretreatment fluorodeoxyglucose positron emission tomography-computed tomography were similar. At a median follow-up of 67 months, the 5-year LC, DFS, and OS for the entire cohort was 62.4%, 41.3%, and 51.9%, respectively. The 5-year LC was significantly better in EDRT compared with SDRT (76.4% vs 49.4%; P = .02). The differences in DFS and OS at 5 years (for EDRT vs SDRT) did not achieve statistical significance (DFS 46.7% vs 31.8%; P = .22 and OS 58.8% vs 45.4%; P = .08). There was a higher incidence of Radiation Therapy Oncology Group grade >2 skin toxic effects (acute) in the EDRT arm (10.4% vs 2.1%; P = .08) with excellent functional outcomes (median Musculoskeletal Tumor Society score = 29) in both arms. CONCLUSIONS: EDRT results in improved LC with good functional outcomes without a significant increase in toxic effects. Radiation dose escalation should be considered for surgically unresectable nonmetastatic ES/PNET.

Modern Therapy for Chest Wall Ewing Sarcoma: An Update of the University of Florida Experience.

PURPOSE: Owing to adjacent critical organs, the aggressive multimodality local therapy necessary for Ewing sarcoma of the chest wall is a challenge. Our previous review of historical outcomes at our institution revealed suboptimal disease control and a high incidence of grade ≥3 toxic effects in patients treated before 2006. The purpose of this study was to evaluate changes during the past decade since the introduction of proton therapy. METHODS AND MATERIALS: Thirty-nine consecutive pediatric patients with a chest wall Ewing sarcoma treated between 2006 and 2020 at the University of Florida were identified. The median maximum tumor diameter was 10 cm (range, 4-28 cm). At diagnosis, 19 patients had local disease and the others had a pleural effusion (11), pleural nodules (5), or pulmonary metastases (4). Patients were treated with chemotherapy regimens according to contemporary North American and European protocols: 7 were treated with preoperative, 18 with postoperative, and 14 with definitive radiation. Preceding primary site treatment, 15 patients required hemithorax radiation and 4 patients underwent whole-lung irradiation using photon techniques. The total median radiation dose to the primary tumor was 52.8 GyRBE [relative biological effectiveness] (range, 44.4-55.8 GyRBE). RESULTS: With a median follow-up of 4 years (range, 0.7-14.7 years), the 5-year local control, progression-free survival, and overall survival rates were 97.2%, 74.4%, and 81.6%, respectively, for the whole cohort. For the 19 patients with nonmetastatic disease, the 5-year local control, progression-free survival, and overall survival rates were 100%, 78.9%, and 78.9%, respectively. No patients developed grade ≥4 toxic effects. Two patients (5%) experienced grade 3 toxic effects related to multimodality treatment; both were patients who required surgery to correct scoliosis. Two patients (5%) developed grade 2 pneumonitis. CONCLUSIONS: Compared with our prior published institutional experience, our data suggest improvements in disease control and multimodality toxic effects since the introduction of proton therapy. This should be confirmed with a larger sample size and longer follow-up.

Modern Therapy for Spinal and Paraspinal Ewing Sarcoma: An Update of the University of Florida Experience.

PURPOSE: In 2010, we published a comprehensive review of our institutional outcomes about treating children with spinal and paraspinal Ewing sarcoma using photon therapy. Multimodality therapy was associated with fair disease control but also with serious toxicity, including a 37% rate of grade 3 or greater toxicity. We therefore sought to assess our more recent experience about treating children with more modern technology and treatment regimens. METHODS AND MATERIALS: Between 2010 and 2021, 32 pediatric patients with nonmetastatic spinal and paraspinal Ewing sarcoma were treated at University of Florida and enrolled in a retrospective outcome study. Median age at diagnosis was 9.8 years (range, 2.1-21.8 years). Within the cervical, thoracic, and lumbar spine regions, 3, 22, and 7 tumors arose, respectively. Median maximum tumor diameter was 5 cm (range, 3-19 cm). At diagnosis, 28 of 32 patients had motor, bowel, or bladder deficits. Chemotherapy was delivered according to contemporary North American and European interval-compressed regimens. Before radiation therapy, 14 patients underwent gross total resection, whereas 18 underwent a biopsy or subtotal resection with cord decompression. All patients were treated with proton therapy; 6 with hardware stabilization also received a component of intensity modulated photon therapy. Median prescription dose was 50.4 gray relative biological effectiveness (GyRBE; range, 45-55.8 GyRBE). Median maximum dose to the spinal cord was 50.2 GyRBE (range, 0-54.9 GyRBE). RESULTS: With a median follow-up of 4.1 years (range, 0.7-9.4 years), the 5-year local control, progression-free survival, and overall survival rates were 92%, 79%, and 85%, respectively. Ten of 30 living patients have residual motor, bowel, or bladder deficits. Overall, 22% of patients experienced Common Terminology Criteria for Adverse Events grade 3 late toxicity related to multimodality treatment: kyphosis (n = 4), esophagitis (n = 2), and chronic kidney disease (n = 1). No patients developed grade 4 or greater toxicity, new neurologic deficits, or second malignancy. CONCLUSIONS: Modern treatment advances may offer an improved therapeutic ratio for pediatric patients with spinal and paraspinal Ewing sarcoma. With appropriate management, most patients can be cured with recovery of long-term neurologic function and modest side effects.

Guide for paediatric radiotherapy procedures.

A third of children with cancer receive radiotherapy as part of their initial treatment, which represents 800 paediatric irradiations per year in France carried out in 15 specialized centres approved on the recommendations of the French national cancer institute in decreasing order of frequency, the types of cancer that require irradiation are: brain tumours, neuroblastomas, Ewing's sarcomas, Hodgkin's lymphomas, soft tissue sarcomas including rhabdomyosarcomas, and nephroblastomas. The treatment guidelines follow the recommendations of the French society for childhood cancers (SFCE) or the French and European prospective protocols. The therapeutic indications, the technical and/and ballistic choices of complex cases are frequently discussed during bimonthly paediatric radiotherapy technical web-conferences. All cancers combined, overall survival being 80%, long-term toxicity logically becomes an important concern, making the preparation of treatments complex. The irradiation methods include all the techniques currently available: 3D conformational irradiation, intensity modulation radiation therapy, irradiation under normal or hypofractionated stereotaxic conditions, brachytherapy and proton therapy. We present the update of the recommendations of the French society for radiation oncology on the indications, the technical methods of realization and the organisation and the specificities of paediatric radiation oncology.

Pulmonary dose tolerance in hemithorax radiotherapy for Ewing sarcoma of the chest wall: Are we overestimating the risk of radiation pneumonitis?

BACKGROUND: Children with chest wall Ewing sarcoma with malignant pulmonary effusion or pleural stranding require hemithorax radiation, often with plans that exceed lung constraints. We investigated disease control and pneumonitis in children requiring hemithorax radiation. PROCEDURE: Eleven children (median age 13 years) received hemithorax radiotherapy. Symptomatic radiation pneumonitis was considered National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) grade 1+ with respiratory symptoms. Mean lung dose (MLD), volume of lung exposed to a dose ≥5 Gy (V5), ≥20 Gy (V20), and ≥35 Gy (V35) were recorded. Adult and pediatric lung constraints were obtained from Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) guidelines and Children's Oncology Group (COG) protocols, respectively. RESULTS: Median hemithorax dose was 15 Gy (1.5 Gy/fraction). Median total dose was 51 Gy (1.8 Gy/fraction). Most plans delivered both protons and photons. The ipsilateral MLD, V5, and V20 were 27.2 Gy, 100%, and 48.3%; the bilateral MLD, V20, and V35 were 14.1 Gy, 22.8%, and 14.3%, respectively. One hundred percent, 36%, and 91% of treatments exceeded recommended adult ipsilateral lung constraints of V5 <65%, V20 <52%, and MLD of 22 Gy; 64%, 45%, and 82% exceeded COG bilateral lung constraints of V20 <20%, MLD <15 Gy, and MLD <12 Gy, respectively; 82% of treatments exceeded the COG ipsilateral lung constraint of V20 <30%. At a median 36 months (range 12-129), the symptomatic radiation pneumonitis incidence was 0%. Two patients progressed with nonpulmonary metastatic disease and died at a median 12 months following radiotherapy. CONCLUSIONS: Existing guidelines may overestimate pneumonitis risk, even among young children receiving multiagent chemotherapy. For children with chest wall Ewing sarcoma and other thoracic malignancies, more data are needed to refine pediatric dose-effect models for pulmonary toxicity.

Four Ways to Decrease Late Toxicity From Pelvic Radiation Therapy in Children and Young Adults.

The use of curative-intent multimodality therapy with chemotherapy, surgery, and radiation results in late toxicities in almost two-thirds of patients with pediatric cancer. When pelvic radiation is used for pediatric malignancies such as rhabdomyosarcoma, lymphoma, neuroblastoma, Ewing sarcoma, and Wilms tumor, the associated late toxicities can affect many normal tissues and may include growth asymmetries, cystitis, infertility, and sexual dysfunction. We describe 4 recommendations of how to prevent or minimize late toxicities from pelvic radiation and review the literature of these pediatric late toxicities.

[Rôle of radiotherapy for sarcomas]. / Place de la radiothérapie dans la prise en charge des sarcomes.

The quality of the initial management of sarcomas is fundamental because it conditions the patient's quality of life and his overall survival. Radiotherapy should be discussed in a multidisciplinary consultation meeting within the framework of the Netsarc+network. The place of radiotherapy in patients with soft tissue or bone sarcoma depends on the histology and tumour location, knowing that it is most often associated with surgery which remains the main treatment. It is part of the standard treatment for grade II and III deep limb sarcomas of 5cm or greater in size and Ewing's sarcomas. In these indications, conformal radiotherapy with modulation of intensity is used routinely, in combination with IGRT. In other locations, such as retroperitoneal sarcomas or uterine sarcomas, radiotherapy is not a standard of care and must be discussed according to the prognostic criteria related to the patient, the tumour, and the previously received treatments. New techniques, such as proton therapy, hadron therapy (carbon ions) are techniques particularly suited to bone sarcomas considered to be radioresistant. However, large prospective trials are lacking in these rare indications, explaining the lack of recommendations of a high level of evidence.

Chest wall and diaphragm reconstruction; a technique not well established in literature - case report.

INTRODUCTION: Regardless of its rarity, and indolent clinical course, chest wall tumor places high morbidity and burden on patients especially when invasion to a neighboring structure is found. Once detected, surgery is the cornerstone for treatment of such etiology combined with chemo-radiotherapy. In order to maintain intact respiratory function, chest wall reconstruction must be performed whenever resection is done. Herein, we present a case of chest wall tumor that necessitated three ribs and part of hemidiaphragm resection and reconstruction with optimal post-operative results. CASE PRESENTATION: A 27-year-old male patient who had chest wall and diaphragm reconstruction for a chest wall Ewing sarcoma, using a single patch of expanded polytetrafluoroethylene (ePTFE) mesh with diaphragm implanted into the middle of the mesh. There were no immediate nor post-operative complications. The patient received post-operative radiotherapy with good functional and cosmetic results. CONCLUSION: We present a novel and safe technique for combined chest wall and diaphragmatic resection following excision of an invading tumor while ensuring cosmesis and functionality of the ribcage as well as the diaphragm.