The Evolving Role of Proton Beam Therapy for Sarcomas

UK guidelines for the management of soft tissue sarcomas

Soft tissue sarcomas (STS) are rare tumours arising in mesenchymal tissues and can occur almost anywhere in the body. Their rarity, and the heterogeneity of subtype and location, means that developing evidence-based guidelines is complicated by the limitations of the data available. This makes it more important that STS are managed by expert multidisciplinary teams, to ensure consistent and optimal treatment, recruitment to clinical trials, and the ongoing accumulation of further data and knowledge. The development of appropriate guidance, by an experienced panel referring to the evidence available, is therefore a useful foundation on which to build progress in the field. These guidelines are an update of the previous versions published in 2010 and 2016 [1, 2]. The original guidelines were drawn up by a panel of UK sarcoma specialists convened under the auspices of the British Sarcoma Group (BSG) and were intended to provide a framework for the multidisciplinary care of patients with soft tissue sarcomas. This iteration of the guidance, as well as updating the general multidisciplinary management of soft tissue sarcoma, includes specific sections relating to the management of sarcomas at defined anatomical sites: gynaecological sarcomas, retroperitoneal sarcomas, breast sarcomas, and skin sarcomas. These are generally managed collaboratively by site specific multidisciplinary teams linked to the regional sarcoma specialist team, as stipulated in the recently published sarcoma service specification [3]. In the UK, any patient with a suspected soft tissue sarcoma should be referred to a specialist regional soft tissues sarcoma service, to be managed by a specialist sarcoma multidisciplinary team. Once the diagnosis has been confirmed using appropriate imaging and a tissue biopsy, the main modality of management is usually surgical excision performed by a specialist surgeon, combined with pre- or post-operative radiotherapy for tumours at higher risk for local recurrence. Systemic anti-cancer therapy (SACT) may be utilised in cases where the histological subtype is considered more sensitive to systemic treatment. Regular follow-up is recommended to assess local control, development of metastatic disease, and any late effects of treatment.

Primary Ewing's Sarcoma affecting the Central Nervous System: A single-center experience and Narrative review

BACKGROUND AND OBJECTIVES

Ewing's sarcoma (EWS) is a malignant round-cell tumor arising from the bone and soft tissue. It is a disease of children and young adults. EWS affecting the central nervous system (cranial and spinal column) is relatively rare with an annual incidence of approximately one case per million in the Western population. Due to their rarity, very few studies are available in the literature. We present our experience of managing 21 such cases, highlighting their clinical, and radiological findings, treatment strategy, and surgical outcomes in patients with primary EWS affecting the central nervous system.

MATERIALS AND METHODS

We retrospectively collected hospital records of patients with primary EWS affecting the CNS (cranial and spinal column), who had been surgically treated in our Neuroscience Center between 2015 and 2023. Patients' demographics, presentation, radiological findings, treatment strategy including surgery and biopsy followed by adjuvant therapy, and outcome at discharge, and the latest follow-up were analyzed from our database.

RESULTS

There were sixteen male and five female patients with a mean age of 18.22 ± 12.73 years (ranging from 6 months to 59 years). The commonest presentation was headache and vomiting in cranial lesions (5/13 patients, 38.46%), and back pain in spinal lesions (4/8 patients, 50%). The site of lesions was cranial in thirteen patients (61.9%) and spinal column in eight patients (38.1%). The commonest site was the frontal region in the cranial group (6 patients, 46.15%) and the lumbar region in the spinal group (4 patients, 50%). All patients underwent surgical intervention [tumor resection (18) and biopsy (3)]. Tumor resection was achieved in 18 patients (85.71%). The extent of resection was gross-total excision in 9 patients (42.86%), near-total excision in 5 patients (23.8%), and tumor decompression in 4 patients (19%). Four patients underwent spinal instrumentation. Fifteen patients (71.42%) received multiagent chemo-radiotherapy according to institute protocol. Five patients (23.8%) with poor KPS expired within 6 months of surgery and could not receive adjuvant therapy. Two patients (9.52%) improved symptomatically, and nine patients (42.86%) remained asymptomatic at a mean follow-up of 25.1 ± 29 months. One patient (4.76%) after receiving 2 cycles of adjuvant therapy had initial improvement but expired later due to disease progression. Four patients after adjuvant chemo-radiotherapy (19%) expired due to systemic spread.

CONCLUSION

Primary EWS affecting the central nervous system is a rare variety. A detailed radiological assessment can aid in adequate planning for safe maximal resection. Timely tissue diagnosis is essential for initiating early treatment. Radical excision followed by adjuvant therapy offers a favorable outcome. Postoperative adjuvant chemo-radiotherapy aids in optimal disease control and surgical outcome. With the current treatment strategy, good surgical outcomes can be achieved. However, metastasis is not uncommon and should be evaluated regularly.

Case report: successful treatment of primary intradural extramedullary extraskeletal Ewing sarcoma in adult patient with intralesional surgery, chemotherapy, and proton beam therapy of the cerebrospinal axis

Ewing sarcoma is a rare malignant neoplasm that primarily affects bone in children. Extraskeletal location is less common, while intradural extramedullary Ewing sarcoma (IEES) in adults is a casuistic phenomenon. Due to its rarity, a standardized treatment strategy for IEES has not been established. The clinical use of proton beam therapy (PBT) for craniospinal irradiation (CSI) in the treatment of IEES has not been reported in the literature. A 41-year-old previously healthy man presented with disabling gluteal and lower extremity pain, decreased sensation, and progressive paraparesis without sphincter dysfunction. Imaging showed intradural extramedullary spinal lesions. The patient underwent urgent surgery. Histology and immunohistochemistry suggested a poorly differentiated neuroendocrine tumor. Negative chromogranin staining and a high Ki67 index prompted further investigation. Next-generation sequencing later confirmed an EWSR1/FLI1 translocation, leading to the diagnosis of extraskeletal Ewing sarcoma. The patient received standardized chemotherapy with marked clinical improvement. PBT CSI was initiated but was interrupted due to COVID-19 and other complications. At 20 months follow-up, no recurrence was observed, and the patient reported an active life. Despite intra-spinal spread and multiple complications, intensive chemotherapy combined with PBT CSI led to a favorable outcome. CSI rather than focal radiotherapy should be considered for patients with IEES limited to the cerebrospinal axis. PBT may be used as an alternative to photon radiotherapy to better spare organs at risk.

Proton Therapy for Spinal Tumors: A Consensus Statement From the Particle Therapy Cooperative Group

PURPOSE

Proton beam therapy (PBT) plays an important role in the management of primary spine tumors. The purpose of this consensus statement was to summarize safe and optimal delivery of PBT for spinal tumors.

METHODS AND MATERIALS

The Particle Therapy Cooperative Group Skull Base/Central nervous system/Sarcoma Subcommittee consisting of radiation oncologists and medical physicists with specific expertise in spinal irradiation developed expert recommendations discussing treatment planning considerations and current approaches in the treatment of primary spinal tumors.

RESULTS

Computed tomography simulation: factors that require significant consideration include (1) patient comfort, (2) setup reproducibility and stability, and (3) accessibility of appropriate beam angles.

SPINE STABILIZATION HARDWARE

If present, hardware should be placed with cross-links well above/below the level of the primary tumor to reduce the metal burden at the level of the tumor bed. New materials that can reduce uncertainties include polyether-ether-ketone and composite polyether-ether-ketone-carbon fiber implants.

FIELD ARRANGEMENT

Appropriate beam selection is required to ensure robust target coverage and organ at risk sparing. Commonly, 2 to 4 treatment fields, typically from posterior and/or posterior-oblique directions, are used.

TREATMENT PLANNING METHODOLOGY

Robust optimization is recommended for all pencil beam scanning plans (the preferred treatment modality) and should consider setup uncertainty (between 3 and 7 mm) and range uncertainty (3%-3.5%). In the presence of metal hardware, use of an increased range uncertainty up to 5% is recommended.

CONCLUSIONS

The Particle Therapy Cooperative Group Skull Base/Central nervous system/Sarcoma Subcommittee has developed recommendations to enable centers to deliver PBT safely and effectively for the management of primary spinal tumors.

A deep-learning-based surrogate model for Monte-Carlo simulations of the linear energy transfer in primary brain tumor patients treated with proton-beam radiotherapy

Objective.This study explores the use of neural networks (NNs) as surrogate models for Monte-Carlo (MC) simulations in predicting the dose-averaged linear energy transfer (LETd) of protons in proton-beam therapy based on the planned dose distribution and patient anatomy in the form of computed tomography (CT) images. As LETdis associated with variability in the relative biological effectiveness (RBE) of protons, we also evaluate the implications of using NN predictions for normal tissue complication probability (NTCP) models within a variable-RBE context.Approach.The predictive performance of three-dimensional NN architectures was evaluated using five-fold cross-validation on a cohort of brain tumor patients (n= 151). The best-performing model was identified and externally validated on patients from a different center (n= 107). LETdpredictions were compared to MC-simulated results in clinically relevant regions of interest. We assessed the impact on NTCP models by leveraging LETdpredictions to derive RBE-weighted doses, using the Wedenberg RBE model.Main results.We found NNs based solely on the planned dose distribution, i.e. without additional usage of CT images, can approximate MC-based LETddistributions. Root mean squared errors (RMSE) for the median LETdwithin the brain, brainstem, CTV, chiasm, lacrimal glands (ipsilateral/contralateral) and optic nerves (ipsilateral/contralateral) were 0.36, 0.87, 0.31, 0.73, 0.68, 1.04, 0.69 and 1.24 keV µm-1, respectively. Although model predictions showed statistically significant differences from MC outputs, these did not result in substantial changes in NTCP predictions, with RMSEs of at most 3.2 percentage points.Significance.The ability of NNs to predict LETdbased solely on planned dose distributions suggests a viable alternative to compute-intensive MC simulations in a variable-RBE setting. This is particularly useful in scenarios where MC simulation data are unavailable, facilitating resource-constrained proton therapy treatment planning, retrospective patient data analysis and further investigations on the variability of proton RBE.

Cone-Beam CT Images as an Indicator of QACT During Adaptive Proton Therapy of Extremity Sarcomas

Purpose

Periodic quality assurance CTs (QACTs) are routine in proton beam therapy. In this study, we tested whether the necessity for a QACT could be determined by evaluating the change in beam path length (BPL) on daily cone-beam CT (CBCT).

Patients and Methods

In this Institutional Review Board-approved study, we retrospectively analyzed 959 CBCT images from 78 patients with sarcomas treated with proton pencil-beam scanning. Plans on 17 QACTs out of a total of 243 were clinically determined to be replanned for various reasons. Daily CBCTs were retrospectively analyzed by automatic ray-tracing of each beam from the isocenter to the skin surface along the central axis. A script was developed for this purpose. Patterns of change in BPL on CBCT images were compared to those from adaptive planning using weekly QACTs.

Results

Sixteen of the 17 adaptive replans showed BPL changes ≥4 mm for at least 1 of the beams on 3 consecutive CBCT sessions. Similarly, 43 of 63 nonadaptively planned patients had BPL changes <4 mm for all of the beams. A new QACT criterium of a BPL change of any beam ≥4 mm on 3 consecutive CBCT sessions resulted in a sensitivity of 94.1% and a specificity of 68.3%. Had the BPL change been used as the QACT predictor, a total of 37 QACTs would have been performed rather than 243 QACTs in clinical practice.

Conclusion

The use of BPL changes on CBCT images represented a significant reduction (85%) in total QACT burden while maintaining treatment quality and accuracy. QACT can be performed only when it is needed, but not in a periodic manner. The benefits of reducing QACT frequency include reducing imaging dose and optimizing patient time and staff resources.

Recent Advances in the Surgical Management of Radiation-Induced Fractures following Soft Tissue Sarcomas

Background: Post-radiation fractures are a significant complication of cancer treatment, often being challenging to manage and impacting patients' quality of life. This study systematically reviews the literature on fractures in irradiated bones, focusing on risk factors, treatment modalities, and prevention strategies. Factors increasing fracture risk include exposure to high doses of radiation of at least 50 Gy, female gender, menopausal age, and periosteal stripping. Additionally further risk factors are the size of the original tumor and osteoporosis. Methods: A search of PubMed yielded 541 articles, with 4 were ultimately included in the review. These retrospective studies focused on patients undergoing Combined Limb-Sparing Surgery and Radiation Therapy for soft tissue sarcoma. Results: Results show post-radiation fractures affect approximately 4% of patients, with the femur being the most frequently affected site. Intramedullary nailing emerges as the gold standard treatment, with prosthetic replacement or megaprostheses used in the metaepiphyseal region and as salvage procedures. Non-union and infection remain formidable complications. Conclusions: This study highlights the importance of prophylactic nailing in fracture prevention and the efficacy of free vascularized fibular flaps to achieve bone union during revision surgeries. Limited case availability and patient follow-up hinder comprehensive studies, impacting treatment outcomes.

Prospective phase II trial of preoperative hypofractionated proton therapy for extremity and truncal soft tissue sarcoma: the PRONTO study rationale and design

BACKGROUND

Oncologic surgical resection is the standard of care for extremity and truncal soft tissue sarcoma (STS), often accompanied by the addition of pre- or postoperative radiation therapy (RT). Preoperative RT may decrease the risk of joint stiffness and fibrosis at the cost of higher rates of wound complications. Hypofractionated, preoperative RT has been shown to provide acceptable outcomes in prospective trials. Proton beam therapy (PBT) provides the means to decrease dose to surrounding organs at risk, such as the skin, bone, soft tissues, and adjacent joint(s), and has not yet been studied in patients with extremity and truncal sarcoma.

METHODS

Our study titled "PROspective phase II trial of preoperative hypofractionated protoN therapy for extremity and Truncal soft tissue sarcOma (PRONTO)" is a non-randomized, prospective phase II trial evaluating the safety and efficacy of preoperative, hypofractionated PBT for patients with STS of the extremity and trunk planned for surgical resection. Adult patients with Eastern Cooperative Group Performance Status ≤ 2 with resectable extremity and truncal STS will be included, with the aim to accrue 40 patients. Treatment will consist of 30 Gy radiobiological equivalent of PBT in 5 fractions delivered every other day, followed by surgical resection 2-12 weeks later. The primary outcome is rate of major wound complications as defined according to the National Cancer Institute of Canada Sarcoma2 (NCIC-SR2) Multicenter Trial. Secondary objectives include rate of late grade ≥ 2 toxicity, local recurrence-free survival and distant metastasis-free survival at 1- and 2-years, functional outcomes, quality of life, and pathologic response.

DISCUSSION

PRONTO represents the first trial evaluating the use of hypofractionated PBT for STS. We aim to prove the safety and efficacy of this approach and to compare our results to historical outcomes established by previous trials. Given the low number of proton centers and limited availability, the short course of PBT may provide the opportunity to treat patients who would otherwise be limited when treating with daily RT over several weeks. We hope that this trial will lead to increased referral patterns, offer benefits towards patient convenience and clinic workflow efficiency, and provide evidence supporting the use of PBT in this setting.

TRIAL REGISTRATION

NCT05917301 (registered 23/6/2023).

A review of the development of histotripsy for extremity tumor ablation with a canine comparative oncology model to inform human treatments

Cancer is a devasting disease resulting in millions of deaths worldwide in both humans and companion animals, including dogs. Treatment of cancer is complex and challenging and therefore often multifaceted, as in the case of osteosarcoma (OS) and soft tissue sarcoma (STS). OS predominantly involves the appendicular skeleton and STS commonly develops in the extremities, resulting in treatment challenges due to the need to balance wide-margin resections to achieve local oncological control against the functional outcomes for the patient. To achieve wide tumor resection, invasive limb salvage surgery is often required, and the patient is at risk for numerous complications which can ultimately lead to impaired limb function and mobility. The advent of tumor ablation techniques offers the exciting potential of developing noninvasive or minimally invasive treatment options for extremity tumors. One promising innovative tumor ablation technique with strong potential to serve as a noninvasive limb salvage treatment for extremity tumor patients is histotripsy. Histotripsy is a novel, noninvasive, non-thermal, and non-ionizing focused ultrasound technique which uses controlled acoustic cavitation to mechanically disintegrate tissue with high precision. In this review, we present the ongoing development of histotripsy as a non-surgical alternative for extremity tumors and highlight the value of spontaneously occurring OS and STS in the pet dog as a comparative oncology research model to advance this field of histotripsy research.

Clinical Insight on Proton Therapy for Paediatric Rhabdomyosarcoma

This paper offers an insight into the use of Proton Beam Therapy (PBT) in paediatric patients with rhabdomyosarcoma (RMS). This paper provides a comprehensive analysis of the literature, investigating comparative photon-proton dosimetry, outcome, and toxicity. In the complex and multimodal scenario of the treatment of RMS, clear evidence of the therapeutic superiority of PBT compared to other modern photon techniques has not yet been demonstrated; however, PBT can be considered an excellent treatment option, in particular for young children and patients with specific primary sites, such as the head and neck area (and especially the parameningeal regions), genito-urinary, pelvic, and paravertebral regions. The unique depth-dose characteristics of protons can be exploited to achieve significant reductions in normal tissue doses and may allow an escalation of tumour doses and greater sparing of normal tissues, thus potentially improving local control while at the same time reducing toxicity and improving quality of life. However, access of children with RMS (and more in general with solid tumors) to PBT remains a challenge, due to the limited number of available proton therapy installations.

Assessing Equity of Access to Proton Beam Therapy: A Literature Review

Proton beam therapy (PBT) is one of the most advanced radiotherapy technologies, with growing evidence to support its use in specific clinical scenarios and exponential growth of demand and capacity worldwide over the past few decades. However, geographical inequalities persist in the distribution of PBT centres, which translate into variations in access and use of this technology. The aim of this work was to look at the factors that contribute to these inequalities, to help raise awareness among stakeholders, governments and policy makers. A literature search was conducted using the Population, Intervention, Comparison, Outcomes (PICO) criteria. The same search strategy was run in Embase and Medline and identified 242 records, which were screened for manual review. Of these, 24 were deemed relevant and were included in this analysis. Most of the 24 publications included in this review originated from the USA (22/24) and involved paediatric patients, teenagers and young adults (61% for children and/or teenagers and young adults versus 39% for adults). The most reported indicator of disparity was socioeconomic status (16/24), followed by geographical location (13/24). All the studies evaluated in this review showed disparities in the access to PBT. As paediatric patients make up a significant proportion of the PBT-eligible patients, equity of access to PBT also raises ethical considerations. Therefore, further research is needed into the equity of access to PBT to reduce the care gap.

Photon and Proton irradiation in Patient-derived, Three-Dimensional Soft Tissue Sarcoma Models

BACKGROUND

Despite their heterogeneity, the current standard preoperative radiotherapy regimen for localized high-grade soft tissue sarcoma (STS) follows a one fits all approach for all STS subtypes. Sarcoma patient-derived three-dimensional cell culture models represent an innovative tool to overcome challenges in clinical research enabling reproducible subtype-specific research on STS. In this pilot study, we present our methodology and preliminary results using STS patient-derived 3D cell cultures that were exposed to different doses of photon and proton radiation. Our aim was: (i) to establish a reproducible method for irradiation of STS patient-derived 3D cell cultures and (ii) to explore the differences in tumor cell viability of two different STS subtypes exposed to increasing doses of photon and proton radiation at different time points.

METHODS

Two patient-derived cell cultures of untreated localized high-grade STS (an undifferentiated pleomorphic sarcoma (UPS) and a pleomorphic liposarcoma (PLS)) were exposed to a single fraction of photon or proton irradiation using doses of 0 Gy (sham irradiation), 2 Gy, 4 Gy, 8 Gy and 16 Gy. Cell viability was measured and compared to sham irradiation at two different time points (four and eight days after irradiation).

RESULTS

The proportion of viable tumor cells four days after photon irradiation for UPS vs. PLS were significantly different with 85% vs. 65% (4 Gy), 80% vs. 50% (8 Gy) and 70% vs. 35% (16 Gy). Proton irradiation led to similar diverging viability curves between UPS vs. PLS four days after irradiation with 90% vs. 75% (4 Gy), 85% vs. 45% (8 Gy) and 80% vs. 35% (16 Gy). Photon and proton radiation displayed only minor differences in cell-killing properties within each cell culture (UPS and PLS). The cell-killing effect of radiation sustained at eight days after irradiation in both cell cultures.

CONCLUSIONS

Pronounced differences in radiosensitivity are evident among UPS and PLS 3D patient-derived sarcoma cell cultures which may reflect the clinical heterogeneity. Photon and proton radiation showed similar dose-dependent cell-killing effectiveness in both 3D cell cultures. Patient-derived 3D STS cell cultures may represent a valuable tool to enable translational studies towards individualized subtype-specific radiotherapy in patients with STS.

Dosimetric comparison between proton beam therapy, intensity modulated radiation therapy, and 3D conformal therapy for soft tissue extremity sarcoma

PURPOSE/OBJECTIVES

Proton beam therapy (PBT) may provide a dosimetric advantage in sparing soft tissue and bone for selected patients with extremity soft sarcoma (eSTS). We compared PBT with photons plans generated using intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT).

MATERIALS/METHODS

Seventeen patients previously treated with pencil beam scanning PBT were included in this study. Of these patients, 14 treated with pre-operative 50 Gy in 25 fractions were analyzed. IMRT and 3D-CRT plans were created to compare against the original PBT plans. Dose-volume histogram (DVH) indices were evaluated amongst PBT, IMRT, and 3D plans. Kruskal-Wallis rank sum tests were used to get the statistical significance. A p value smaller than .05 was considered to be statistically significant.

RESULTS

For the clinical target volume (CTV), D2%, D95%, D98%, D_min, D_max, and V50Gy, were assessed. D_min, D1%, D_max, D_mean, V1Gy, V5Gy, and V50Gy were evaluated for the adjacent soft tissue. D1%, D_max, D_mean, and V35-50% were evaluated for bone. All plans met CTV target coverage. The PBT plans delivered less dose to soft tissue and bone. The mean dose to the soft tissue was 2 Gy, 11 Gy, and 13 Gy for PBT, IMRT, and 3D, respectively (p < .001). The mean dose to adjacent bone was 15 Gy, 26 Gy, and 28 Gy for PBT, IMRT, and 3D, respectively (p = .022).

CONCLUSION

PBT plans for selected patients with eSTS demonstrated improved sparing of circumferential soft tissue and adjacent bone compared to IMRT and 3D-CRT. Further evaluation will determine if this improved dosimetry correlates with reduced toxicity and improved quality of life.

Comparing Ultra-hypofractionated Proton versus Photon Therapy in Extremity Soft Tissue Sarcoma

Purpose

Recent single institution, phase II evidence has demonstrated the feasibility and efficacy of ultra-hypofractionated, preoperative photon therapy in 5 fractions for the treatment of soft tissue sarcoma (STS). Our purpose was to evaluate the dosimetric benefits of modern scanning beam proton therapy compared with conventional photon radiation therapy (RT) for the neoadjuvant treatment of adult extremity STS.

Materials and Methods

Existing proton and photon plans for 11 adult patients with STS of the lower extremities previously treated preoperatively with neoadjuvant RT at our center were used to create proton therapy plans using Raystation Treatment Planning System v10.A. Volumes were delineated, and doses reported consistent with International Commission on Radiation Units and Measurements reports 50, 62, and 78. Target volumes were optimized such that 100% clinical target volume (CTV) was covered by 99% of the prescription dose. The prescribed dose was 30 Gy for PT and RT delivered in 5 fractions. For proton therapy, doses are reported in GyRBE = 1.1 Gy. The constraints for adjacent organs at risk (OARs) within 1 cm of the CTV were the following: femur V30Gy ≤ 50%, joint V30Gy < 50%, femoral head V30Gy ≤ 5 cm3, strip V12 ≤ 10%, and skin V12 < 50%. Target coverage goals, OAR constraints, and integral dose were compared by Student t test with P < .05 significance.

Results

A minimum 99% CTV coverage was achieved for all plans. OAR dose constraints were achieved for all proton and photon plans; however, mean doses to the femur (10.7 ± 8.5 vs 16.1 ± 7.7 GyRBE), femoral head (2.0 ± 4.4 vs 3.6 ± 6.4 GyRBE), and proximal joint (1.8 ± 2.4 vs 3.5 ± 4.4 GyRBE) were all significantly lower with PT vs intensity-modulated radiation therapy (IMRT) (all P < .05). Integral dose was significantly reduced for proton vs photon plans. Conformity and heterogeneity indices were significantly better for proton therapy.

Conclusion

Proton therapy maintained target coverage while significantly reducing integral and mean doses to the proximal organs at risk compared with RT. Further prospective investigation is warranted to validate these findings and potential benefit in the management of adult STS.

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.

Early Experience Using Proton Beam Therapy for Extremity Soft Tissue Sarcoma: A Multicenter Study

Purpose

Proton beam therapy (PBT) may provide an advantage when planning well-selected patients with extremity soft tissue sarcoma (eSTS), specifically for large, anatomically challenging cases. We analyzed our early experience with PBT on toxicity and outcomes.

Materials and Methods

A retrospective study was performed for eSTS treated between June 2016 and October 2020 with pencil beam scanning PBT at 2 institutions. Diagnostic, treatment, and toxicity characteristics were gathered from baseline to last follow-up or death. Wound complications were defined as secondary operations for wound repair (debridement, drainage, skin graft, and muscle flap) or nonoperative management requiring hospitalization. Statistical analysis was performed with R software.

Results

Twenty consecutive patients with a median age 51.5 years (range, 19–78 years) were included. Median follow-up was 13.7 months (range, 1.7–48.1 months). Tumor presentation was primary (n = 17) or recurrent after prior combined modality therapy (n = 3). Tumor location was either lower extremity (n = 16) or upper extremity (n = 4). Radiation was delivered preoperatively in most patients (n = 18). Median pretreatment tumor size was 7.9 cm (range, 1.3 –30.0 cm). The 1-year locoregional control was 100%. Four patients (20%) had developed metastatic disease by end of follow-up. Maximum toxicity for acute dermatitis was grade 2 in 8 patients (40%) and grade 3 in 3 patients (15%). After preoperative radiation and surgical resection, acute wound complications occurred in 6 patients (35%). Tumor size was larger in patients with acute wound complications compared with those without (medians 16 cm, range [12–30.0 cm] vs 6.3 cm, [1.3–14.4 cm], P = .003).

Conclusion

PBT for well selected eSTS cases demonstrated excellent local control and similar acute wound complication rate comparable to historic controls. Long-term follow-up and further dosimetric analyses will provide further insight into potential advantages of PBT in this patient population.

Parameningeal alveolar rhabdomyosarcoma in a child

This is the case of a parameningeal alveolar rhabdomyosarcoma (ARMS) in a 13-year-old boy who presented with painless loss of vision in the right eye, but very few other physical signs. The ARMS diagnosis was confirmed with imaging and molecular characterisation of the tumour. Despite tolerating the initial chemotherapy and radiotherapy regimens, there was leptomeningeal recurrence and the patient unfortunately passed away. Parameningeal ARMS occurs in an area of the body, which leads to a wide variety of possible presenting symptoms, creating a long list of differentials that can delay treatment. This tumour subtype has a poor prognosis, and due to the location of the tumour around vital structures in the head, treatment toxicities must be taken into account. This highlights the necessity for having a strong index of suspicion for this tumour in atypical presentations in children, and the necessity for prompt treatment to prevent leptomeningeal disease from occurring.

A rare case of chordoma presenting as a Pancoast tumor

The notochord is the defining structure of all chordate embryos. It is a midline structure ventral to the ectoderm, neural plates, and neural arch. Remnants of the notochord ultimately give rise to the nucleus pulposus. The function of the notochord is to organize the surrounding structures. Chordoma is a rare malignant bone tumor arising from remnants of the notochord. These tumors are indolent and can present as incidental or locally advanced involving adjacent structures. These tumors typically present at the skull base and sacral spine but more rarely can be seen on the cervical and thoracic spine. Rare cases of chordoma invading the brachial plexus have been recorded. Surgical resection is the mainstay of treatment for chordomas. We would like to discuss a novel presentation of a chordoma as a Pancoast tumor, and aim to highlight the clinical importance of accurate diagnosis and planning therapy along with poor prognosis of incomplete surgical resection.

Ewing Sarcoma-Diagnosis, Treatment, Clinical Challenges and Future Perspectives

Ewing sarcoma, a highly aggressive bone and soft-tissue cancer, is considered a prime example of the paradigms of a translocation-positive sarcoma: a genetically rather simple disease with a specific and neomorphic-potential therapeutic target, whose oncogenic role was irrefutably defined decades ago. This is a disease that by definition has micrometastatic disease at diagnosis and a dismal prognosis for patients with macrometastatic or recurrent disease. International collaborations have defined the current standard of care in prospective studies, delivering multiple cycles of systemic therapy combined with local treatment; both are associated with significant morbidity that may result in strong psychological and physical burden for survivors. Nevertheless, the combination of non-directed chemotherapeutics and ever-evolving local modalities nowadays achieve a realistic chance of cure for the majority of patients with Ewing sarcoma. In this review, we focus on the current standard of diagnosis and treatment while attempting to answer some of the most pressing questions in clinical practice. In addition, this review provides scientific answers to clinical phenomena and occasionally defines the resulting translational studies needed to overcome the hurdle of treatment-associated morbidities and, most importantly, non-survival.

Impact of NICE guidelines on the survival of patients with soft-tissue sarcomas

AIMS

Urgent referral to a specialist centre for patients with a soft-tissue sarcoma (STS) has been recommended by the National Institute for Health and Care Excellence (NICE) in the UK since 2006. However, the impact of this recommendation on the prognosis for these patients remains unclear. We aimed to determine the impact of the NICE guidelines on the disease-specific survival (DSS) of patients with an STS.

METHODS

A total of 2,427 patients with an STS referred to a supraregional centre in the ten-year periods before (n = 1,386) and after (n = 1,041) the issue of the NICE guidelines were evaluated.

RESULTS

The mean size of the tumour was significantly smaller at the time of diagnosis (10.3 cm (SD 6.5) vs 9.1 cm (SD 6.2); p < 0.001) and the number of patients who had undergone an inadvertent excision significantly decreased (28% (n = 389) vs 20% (n = 204); p < 0.001) following the introduction of the NICE guidelines. The five-year DSS was 63% in the pre-NICE and 71% in post-NICE groups (p < 0.001). The improved survival was more significant for those with a high-grade tumour (pre-NICE, 48%; post-NICE, 68%; p < 0.001). In those with a high-grade tumour, the mean size of the tumour (11.6 cm (SD 6.2) vs 9.6 cm (SD 5.8); p < 0.001) and the number of patients with metastasis at the time of diagnosis (15% (n = 124 vs 10% (n = 80); p = 0.007) significantly decreased in the post-NICE group.

CONCLUSION

An improvement in survival was seen after the introduction of the NICE guidelines, especially in patients with a high-grade STS. More patients were referred at an earlier stage, indicating a clearer pathway after the issue of national policy for the management of STSs in the UK. Cite this article: Bone Joint J 2021;103-B(3):569-577.

Osteosarcoma: a review of current and future therapeutic approaches

Osteosarcoma (OS) is the most common primary bone malignancy that affects children and young adults. OS is characterized by a high degree of malignancy, strong invasiveness, rapid disease progression, and extremely high mortality rate; it is considered as a serious threat to the human health globally. The incidence of OS is common in the metaphysis of long tubular bones, but rare in the spine, pelvis, and sacrum areas; moreover, majority of the OS patients present with only a single lesion. OS has a bimodal distribution pattern, that is, its incidence peaks in the second decade of life and in late adulthood. We examine historical and current literature to present a succinct review of OS. In this review, we have discussed the types, clinical diagnosis, and modern and future treatment methods of OS. The purpose of this article is to inspire new ideas to develop more effective therapeutic options.

Managing axial bone sarcomas in childhood

Introduction: Axial osteosarcoma and Ewing sarcoma are rare, aggressive neoplasms with a worse prognosis than with tumors involving the extremities because they are more likely to be associated with larger tumor volumes, older age, primary metastases, and a poor histological response to chemotherapy. The 5-year OS rates are reportedly in the range of 18-41% for axial osteosarcoma, and 46-64% for Ewing sarcoma.Area covered: The treatment of axial bone tumors is the same as for extremity bone tumors, and includes chemotherapy, surgery and/or radiotherapy.Expert opinion: Local treatment of axial tumors is particularly difficult due to their proximity to neurological and vascular structures, which often makes extensive and en bloc resections impossible without causing significant morbidity. The incidence of local relapse is consequently high, and this is the main issue in the treatment of these tumors. Radiotherapy is an option in the case of surgical resections with close or positive margins, as well as for inoperable tumors. Delivering high doses of RT to the spinal cord can be dangerous. Given the complexity and rarity of these tumors, it is essential for this subset of patients to be treated at selected reference institutions with specific expertise and multidisciplinary skills.

Right atrial cardiac angiosarcoma treated with concurrent proton beam therapy and paclitaxel: A novel approach to a rare disease

Cardiac angiosarcoma is a rare malignancy with an aggressive course and poor prognosis. We present a 26‐year old man who came to our clinic with shortness of breath and was diagnosed with a right‐sided atrial mass. He underwent urgent resection of the mass. The pathology confirmed the mass to be cardiac angiosarcoma with positive microscopic margins (R1 resection). Since reresection was not feasible, the patient started treatment with concurrent paclitaxel (80 mg/m² weekly) and proton beam therapy (61 Cobalt equivalent delivered over five weeks). After completing the concurrent chemotherapy and radiation therapy, he was treated with adjuvant chemotherapy using gemcitabine (900 mg/m² on Days 1 and 8) and docetaxel (100 mg/m² on Day 8) every three weeks. After three cycles, the patient developed severe dermatitis, and hence further chemotherapy was withheld. The patient is alive at 26 months since receiving his surgery and 18 months since the completion of treatment. Patients with cardiac angiosarcoma who undergo R1 resection have a median survival of six months. More radical approaches such as orthotopic heart‐lung transplant or prolonged durations of chemotherapy lead to minimal improvement in survival at the cost of increased morbidity. Here, we describe a novel approach to a rare disease that resulted in prolonged survival and led to a better quality of life without any long‐term morbidity to the patient.

Evaluations of a flat-panel based compact daily quality assurance device for proton pencil beam scanning (PBS) system

PURPOSE

To evaluate the flat-panel detector quenching effect and clinical usability of a flat-panel based compact QA device for PBS daily constancy measurements.

MATERIALS & METHOD

The QA device, named Sphinx Compact, is composed of a 20x20 cm² flat-panel imager mounted on a portable frame with removable plastic modules for constancy checks of proton energy (100 MeV, 150 MeV, 200 MeV), Spread-Out-Bragg-Peak (SOBP) profile, and machine output. The potential quenching effect of the flat-panel detector was evaluated. Daily PBS QA tests of X-ray/proton isocenter coincidence, the constancy of proton spot position and sigma as well as the energy of pristine proton beam, and the flatness of SOBP proton beam through the 'transformed' profile were performed and analyzed. Furthermore, the sensitivity of detecting energy changes of pristine proton beam was also evaluated.

RESULTS

The quenching effect was observed at depths near the pristine peak regions. The flat-panel measured range of the distal 80% is within 0.9 mm to the defined ranges of the delivered proton beams. X-ray/proton isocenter coincidence tests demonstrated maximum mismatch of 0.3 mm between the two isocenters. The device can detect 0.1 mm change of spot position and 0.1 MeV energy changes of pristine proton beams. The measured transformed SOBP beam profile through the wedge module rendered as flat.

CONCLUSIONS

Even though the flat-panel detector exhibited quenching effect at the Bragg peak region, the proton range can still be accurately measured. The device can fulfill the requirements of the daily QA tests recommended by the AAPM TG224 Report.

Unraveling the Heterogeneity of Sarcoma Survivors' Health-Related Quality of Life Regarding Primary Sarcoma Location: Results from the SURVSARC Study

Simple Summary

Sarcomas are a rare group of heterogenous tumors that can develop anywhere in the body. Currently, studies on health-related quality of life (HRQoL) focus on sarcomas of the arm and leg or have too small sample sizes to examine the heterogeneity between different sarcoma locations, leading to limited insight into HRQoL of survivors with specific sarcoma locations. The aim of this study was to assess differences in HRQoL and examine treatment-specific HRQoL issues per sarcoma location. We found, in a population of 1099 sarcoma survivors, different patterns of HRQoL according to primary sarcoma location and a high number of additional, unique treatment-specific HRQoL issues per location, which were not captured with the general HRQoL questionnaire used in cancer patients. This indicates that the currently used HRQoL measures are too generic to capture all sarcoma-related issues, emphasizing the necessity for a comprehensive sarcoma-specific HRQoL measurement strategy.

Abstract

Sarcoma patients experience physical and psychological symptoms, depending on age of onset, subtype, treatment, stage, and location of the sarcoma, which can adversely affect patients’ health-related quality of life (HRQoL). This study aimed to unravel the heterogeneity of sarcoma survivors’ HRQoL regarding primary sarcoma location. A cross-sectional study was conducted among Dutch sarcoma survivors (N = 1099) aged ≥18, diagnosed 2–10 years ago. Primary sarcoma locations were head and neck, chest, abdominal including retroperitoneal, pelvis including urogenital organs, axial skeleton, extremities (upper and lower), breast, skin and other locations. The European Organization for Research and Treatment of Cancer—Quality of Life Questionnaire (EORTC QLQ)-C30 was used to measure HRQoL accompanied by treatment-specific HRQoL questions. Sociodemographic and clinical characteristics were collected from the Netherlands Cancer Registry. Axial skeleton sarcomas had the lowest functioning levels and highest symptoms compared to other locations. Skin sarcomas had the highest functioning levels and lowest symptoms on most scales. Bone sarcomas scored worse on several HRQoL domains compared to soft tissue sarcomas. High prevalence of treatment-specific HRQoL issues were found per location. In conclusion, sarcomas can present everywhere, which is reflected by different HRQoL outcomes according to primary sarcoma location. The currently used HRQoL measure lacks treatment-specific questions and is too generic to capture all sarcoma-related issues, emphasizing the necessity for a comprehensive sarcoma-specific HRQoL measurement strategy.

Guideline for Limb-Salvage Treatment of Osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor, occurring mainly in children and adolescents, and the limbs are the main affected sites. At present, limb‐salvage treatment is considered as an effective basic standard treatment for osteosarcoma of the limb. China has a vast territory, but the development of technology is not balanced,which requires sufficient theoretical coverage, strong technical guidance and the application of limb‐salvage treatment guidelines to the treatment of osteosarcoma. Therefore, to standardize and promote the development of limb‐salvage surgery technology and improve the success rate of limb‐salvage treatment, this guide systematically introduces limb‐salvage techniques for the treatment of patients with limb osteosarcoma through definition of limb‐salvage treatment, surgical methods, efficacy evaluation, postoperative treatment and prevention of complications, rehabilitation guidance, and follow‐up advice.

Big data-driven precision medicine: Starting the custom-made era of iatrology

Precision medicine is a new therapeutic concept and method emerging in recent years. The rapid development of precision medicine is driven by the development of omics related technology, biological information and big data science. Precision medicine is provided to implement precise and personalized treatment for diseases and specific patients. Precision medicine is commonly used in the diagnosis, treatment and prevention of various diseases. This review introduces the application of precision medicine in eight systematic diseases of the human body, and systematically presenting the current situation of precision medicine. At the same time, the shortcomings and limitations of precision medicine are pointed out. Finally, we prospect the development of precision medicine.

Advances in the management of primary bone sarcomas of the skull base

Skull base primary malignancies represent a heterogeneous group of histologic diagnoses and sarcomas of the skull base are specific malignant tumors that arise from mesenchymal cells and can be classified by site of origin into bony and soft tissue sarcomas. The most common bony sarcomas include: chondrosarcoma, osteosarcoma, chordoma, Ewing's sarcoma. Given the relative rarity of each histologic diagnosis, especially in the skull base, there is limited published data to guide the management of patients with skull base sarcomas. An electronic search of the literature was performed to obtain key publications in the management of bony sarcomas of the skull base published within the last decade. This article is thus a review of the multi-disciplinary management principles of primary bony sarcomas of the skull base. Of note, there have been several recent advancements in the realm of skull base sarcoma management that have resulted in improved survival. These include advances in: imaging and diagnostic techniques, surgical techniques that incorporate oncologic surgical principles, conformal radiation paradigms and targeted systemic therapies. Early access to coordinated multi-disciplinary subspecialty care immediately at suspicion of diagnosis has further improved outcomes. There are several ongoing trials in the realms of radiation therapy and systemic therapy that will hopefully provide further insight about the optimal management of bony sarcomas of the skull base.

Strategies to Prevent Cardiotoxicity

OPINION STATEMENT

Cardiovascular disease is a leading cause of death among cancer survivors. While the field of cardiology as a whole is driven by evidence generated through robust clinical trials, data in cardio-oncology is limited to a relatively small number of prospective clinical trials with heterogeneous groups of cancer patients. In addition, many pharmaceutical trials in oncology are flawed from a cardiovascular perspective because they exclude patients with significant cardiovascular (CV) history and have wide variation in the definitions of CV events and cardiotoxicity. Ultimately, oncology trials often underrepresent the possibility of cardiovascular events in a "real world" population. Thus, the signal for CV toxicity from a cancer treatment is often not manifested until phase IV studies; where we are often caught trying to mitigate the CV effects rather than preventing them. Most of the data about cardiotoxicity from cancer therapy and cardioprotective strategies has been developed from our experience in using anthracyclines for over 50 years with dramatic improvement in cancer survivorship. However, as we are in an era where cancer drug discovery is moving at lightning pace with increasing survival rates, it is imperative to move beyond anthracyclines and commit to research on the cardiovascular side effects of all aspects of cancer therapy with a focus on prevention. We emphasize the role of pre-cancer treatment CV assessment to anticipate cardiac issues and ultimately optimizing CV risk prior to cancer therapy as an opportunity to mitigate cardiovascular risk from cancer therapy.

Impact of different treatment techniques for pediatric Ewing sarcoma of the chest wall: IMRT, 3DCPT, and IMPT with/without beam aperture

Purpose

To evaluate the dosimetric differences between photon intensity‐modulated radiation therapy (IMRT) plans, 3D conformal proton therapy (3DCPT), and intensity‐modulated proton therapy (IMPT) plans and to investigate the dosimetric impact of different beam spot size and beam apertures in IMPT for pediatric Ewing sarcoma of the chest wall.

Methods and Materials

Six proton pediatric patients with Ewing sarcoma in the upper, middle, and lower thoracic spine regions as well as upper lumbar spine region were treated with 3DCPT and retrospectively planned with photon IMRT and IMPT nozzles of different beam spot sizes with/without beam apertures. The plan dose distributions were compared both on target conformity and homogeneity, and on organs‐at‐risk (OARs) sparing using QUANTEC metrics of the lung, heart, liver, and kidney. The total integral doses of healthy tissue of all plans were also evaluated.

Results

Target conformity and homogeneity indices are generally better for the IMPT plans with beam aperture. Doses to the lung, heart, and liver for all patients are substantially lower with the 3DPT and IMPT plans than those of IMRT plans. In the IMPT plans with large spot without beam aperture, some OAR doses are higher than those of 3DCPT plans. The integral dose of each photon IMRT plan ranged from 2 to 4.3 times of proton plans.

Conclusion

Compared to IMRT, proton therapy delivers significant lower dose to almost all OARs and much lower healthy tissue integral dose. Compared to 3DCPT, IMPT with small beam spot size or using beam aperture has better dose conformity to the target.

The role of proton therapy in pediatric malignancies: Recent advances and future directions

Proton radiotherapy has promised an advantage in safely treating pediatric malignancies with an increased capability to spare normal tissues, reducing the risk of both acute and late toxicity. The past decade has seen the proliferation of more than 30 proton facilities in the United States, with increased capacity to provide access to approximately 3,000 children per year who will require radiotherapy for their disease. We provide a review of the initial efforts to describe outcomes after proton therapy across the common pediatric disease sites. We discuss the main attempts to assess comparative efficacy between proton and photon radiotherapy concerning toxicity. We also discuss recent efforts of multi-institutional registries aimed at accelerating research to better define the optimal treatment paradigm for children requiring radiotherapy for cure.

Spindle Cell Sarcoma of the Maxilla: A Rare Entity, Case Report, and Review of the Literature

Spindle cell sarcoma (SCS) is a malignancy, with the most recent Surveillance, Epidemiology, and End Results (SEER) data citing a total of 250 reported cases occurring in the head and neck. Of these cases, none originated in the maxillofacial hard tissue. To the best of our knowledge, only 2 cases of primary osseous SCS of the maxillofacial region have been reported. These cases were not accounted for in the SEER data. The diagnosis of SCS requires its differentiation from other sarcomas and spindle cell neoplasms. Therefore, a comprehensive review to reinforce its inclusion in oral and maxillofacial surgeons' differential diagnosis for osseous neoplastic pathology is desired. In the present case report, we have described a maxillary SCS in a patient with an initial diagnosis of a spindle cell lesion of uncertain biologic behavior. We reviewed the data for SCS, including the epidemiologic data, diagnostic challenges, clinical and radiographic presentations, prognostic indicators, and treatment.

Paediatric proton therapy

Proton beam therapy is a highly conformal form of radiation therapy, which currently represents an important therapeutic component in multidisciplinary management in paediatric oncology. The precise adjustability of protons results in a reduction of radiation-related long-term side-effects and secondary malignancy induction, which is of particular importance for the quality of life. Proton irradiation has been shown to offer significant advantages over conventional photon-based radiotherapy, although the biological effectiveness of both irradiation modalities is comparable. This review evaluates current data from clinical and dosimetric studies on the treatment of tumours of the central nervous system, soft tissue and bone sarcomas of the head and neck region, paraspinal or pelvic region, and retinoblastoma. To date, the clinical results of irradiating childhood tumours with high-precision proton therapy are promising both with regard to tumour cure and the reduction of adverse events. Modern proton therapy techniques such as pencil beam scanning and intensity modulation are increasingly established modern facilities. However, further investigations with larger patient cohorts and longer follow-up periods are required, in order to be able to have clear evidence on clinical benefits.

Radiotherapy resistance in chondrosarcoma cells; a possible correlation with alterations in cell cycle related genes

Background

Conventional chondrosarcomas are malignant cartilage tumors considered radioresistant. Nevertheless, retrospective series show a small but significant survival benefit for patients with locally advanced disease treated with radiotherapy. And, in daily practice when considered inoperable their irradiation is an accepted indication for proton beam radiotherapy. Therefore, we investigated the sensitivity of chondrosarcoma cell lines and -tissue samples towards radiotherapy and screened for biomarkers to identify predictors of radiosensitivity.

Methods

Proliferation and clonogenic assays were performed in chondrosarcoma cell lines after γ-radiation in combination with mutant IDH1 inhibitor AGI-5198. In addition, glutathione levels were measured using mass spectrometry. Chondrosarcoma tumor explants were irradiated after which γ-H2AX foci were counted. Mutation analysis was performed using the Ion AmpliSeq™ Cancer Hotspot Panel and immunohistochemical staining’s were performed for P-S6, LC-3B, P53, Bcl-2, Bcl-xl and Survivin. Results were correlated with the number of γ-H2AX foci.

Results

Chondrosarcoma cell lines were variably γ-radiation resistant. No difference in radiosensitivity, nor glutathione levels was observed after treatment with AGI-5198. Irradiated chondrosarcoma patient tissue presented a variable increase in γ-H2AX foci compared to non-radiated tissue. Samples were divided into two groups, high and low radioresistant, based on the amount of γ-H2AX foci. All four highly resistant tumors exhibited mutations in the pRb pathway, while none of the less radioresistant tumors showed mutations in these genes.

Conclusions

Chondrosarcoma cell lines as well as primary tumors are variably radioresistant, particularly in case of a defective Rb pathway. Whether selection for radiotherapy can be based upon an intact Rb pathway should be further investigated.

Electronic supplementary material

The online version of this article (10.1186/s13569-019-0119-0) contains supplementary material, which is available to authorized users.

[Radiotherapy after tumour prostheses-status, indication, coordination]

BACKGROUND

Patients with complex tumour prostheses often require radiotherapy or radiochemotherapy.

OBJECTIVES

Possible tumour diagnoses, indications, planning and therapy procedures, and prognosis of radiotherapy in the context of an interdisciplinary treatment for bone sarcomas are reviewed, including interactions of metal prostheses with radiation and possible subsequent complications.

METHODS

Literature search, summary of personal experience.

RESULTS

Complex prosthetic procedures are usually applied to patients suffering from Ewing sarcoma or osteosarcoma. In patients with Ewing sarcoma, radiotherapy is an integral part of multimodal treatment, while in patients with osteosarcoma radiotherapy is indicated in special situations. Planning and implementation of radiotherapy treatment can be impaired by metal implants within the target volume (artefacts in the planning computerized tomography, interaction of metal with the therapeutic beam). However, it is-to our knowledge-a point of debate whether radiotherapy after implantation of a prosthesis could impair healing or prosthesis fixation to bone. The data available in the literature suggest that prostheses implanted after radiotherapy entail a higher rate of complications. Multidisciplinary treatment improves the prognosis for these patients markedly.

CONCLUSIONS

Patients with sarcomas of the bone undergoing interdisciplinary treatment consisting of surgery, radiotherapy and chemotherapy have a favourable prognosis and an acceptable functionality of the limb can be expected.

Radiotherapy for parapharyngeal space tumors

A wide variety of tumors, both benign and malignant, occur in the parapharyngeal space. Depending on histology and extent, treatment may include surgery and/or radiotherapy (RT). Herein we discuss the role of RT in the management of some of the more commonly encountered neoplasms, including salivary gland tumors, paragangliomas, schwannomas, and soft-tissue sarcomas.

Evolving Radiotherapy Techniques in Paediatric Oncology

AIMS

Childhood cancer is rare and survival of childhood cancer has increased up to 80% at 5 years after diagnosis. Radiotherapy is an important element of the multimodal treatment concept. However, due to growing tissue, children are particularly sensitive to radiation-related side-effects and the induction of secondary malignancies. However, radiotherapy techniques have continuously progressed. In addition, modern treatment concepts have been improved in order to minimise long-term effects. Today, radiotherapy is used for various tumour types in childhood, such as sarcomas and tumours of the central nervous system.

MATERIALS AND METHODS

External beam therapy with either photons or protons and brachytherapy are predominantly used for the treatment of childhood tumours. Technical developments and features, as well as clinical outcomes, for several tumour entities are presented.

RESULTS

The development of radiotherapy techniques, as well as risk-adapted therapy concepts, resulted in promising outcome regarding tumour control, survival and therapy-related side-effects. It is assumed that proton therapy will be increasingly used for treating children in the future. However, more data have to be collected through multi-institutional registries in order to strengthen the evidence.

CONCLUSION

The development of radiotherapy techniques is beneficial for children in terms of reducing dose exposure. As compared with other modern and highly conformal techniques, particularly proton therapy may achieve high survival rates and tumour control rates while decreasing the risk for side-effects. However, clinical evidence for modern radiotherapy techniques is still limited today. An optimal patient triaging with the selection of the most appropriate radiation technique for each individual patient will be an important goal for the future.

Proton therapy for pediatric malignancies: Fact, figures and costs. A joint consensus statement from the pediatric subcommittee of PTCOG, PROS and EPTN

Radiotherapy plays an important role in the management of childhood cancer, with the primary aim of achieving the highest likelihood of cure with the lowest risk of radiation-induced morbidity. Proton therapy (PT) provides an undisputable advantage by reducing the radiation 'bath' dose delivered to non-target structures/volume while optimally covering the tumor with tumoricidal dose. This treatment modality comes, however, with an additional costs compared to conventional radiotherapy that could put substantial financial pressure to the health care systems with societal implications. In this review we assess the data available to the oncology community of PT delivered to children with cancer, discuss on the urgency to develop high-quality data. Additionally, we look at the advantage of combining systemic agents with protons and look at the cost-effectiveness data published so far.

Ewing sarcoma of the head and neck: The Mayo Clinic experience

BACKGROUND

Treatment options of Ewing sarcoma of the head and neck include surgery, radiotherapy (RT), and chemoradiotherapy. However, local control can be challenging.

METHODS

We conducted a retrospective review of all patients with head and neck Ewing sarcoma treated from 1972 to 2015 at a single tertiary care hospital.

RESULTS

Seventeen patients met criteria (median 21 years, range 5-58 years; 5 women). Mean follow-up was 10.4 years (range 2.2-39 years). Tumors occurred commonly in the cervical spine (5/17), the skull (3/17), and the paranasal sinuses (3/17). A total of 14 of 17 patients underwent surgical resection, 9 with gross total resection. After multimodality therapy, the 5-year overall survival (OS) and recurrence-free survival (RFS) was 87% and 75%, respectively.

CONCLUSION

Combined multimodal treatment resulted in a 5-year OS and RFS of 87% and 75%, respectively. Aggressive surgical resection with adjuvant chemoradiotherapy should be considered. Although negative margin surgery is the goal, subtotal resection may be acceptable in the setting of adjuvant treatment.

Long-term results in children with head and neck rhabdomyosarcoma: A report from the Italian Soft Tissue Sarcoma Committee

BACKGROUND

Rhabdomyosarcoma (RMS) occurring at nonparameningeal head and neck (NPM-HN) sites carries a better prognosis than parameningeal RMS and some other sites. We analyzed the treatments administered and results obtained in patients with localized NPM-HN RMS, included in the protocols coordinated by the Italian Soft Tissue Sarcoma Committee (STSC), in an effort to identify prognostic factors that could facilitate the tailoring of treatment.

METHODS

Sixty-six patients up to 18 years of age with previously untreated, localized NPM-HN RMS were prospectively registered in three consecutive protocols: RMS79, RMS88, and RMS96. Primary surgery was recommended when complete tumor resection was deemed feasible without mutilations. In other cases, only a biopsy was performed, followed by chemotherapy and delayed surgery and/or radiotherapy (RT).

RESULTS

NPM-HN RMS showed favorable characteristics: 72.7% were <5 cm, 72.7% were T1, and 80.3% were N0. With a median follow-up of 16 years (range 7-27), the 10-year progression-free survival and overall survival for the whole group were 65.1% (confidence interval [CI]: 52.3-75.3) and 74.2% (CI: 61.8-83.1). Progressive improvement has been seen in the successive protocols. Age and RT emerged as independent prognostic factors. The group of young children (age <l year) not irradiated was at high risk of failure.

CONCLUSION

The experience of the Italian STSC confirms that NPM-HN RMS has a favorable prognosis, which has improved over the years due to a better, multimodal treatment approach. RT has an important role, but different modalities such as proton therapy and brachytherapy should be explored in systematic ways in very young children.

Skull and Spinal Ewing's Sarcoma in Children: An Institutional Study

Background:

Ewing’s sarcoma is a disease of children and young adults and occurs most often in bone and soft tissues. The intracranial and spinal manifestation of the disease is rare and reported incidence is 1%–6%.

Aims and Objectives:

We conducted this study to determine the surgical outcome of children with skull and spine Ewing’s sarcoma (SSES).

Methods:

This is a prospective analysis of 13 patients of SSES who reported to the Department of Neurosurgery, Nizam’s Institute of Medical Sciences, Hyderabad, Telangana, India, between 2014 and 2016. All cases after detailed examination, magnetic resonance imaging, and computed tomography scan were subjected to surgery followed by adjuvant therapy comprising chemotherapy and radiotherapy. Outcome was analyzed at 6 months as well at latest follow-up. Neurological function, local recurrence, primary or secondary nature of the disease, distant relapse, and treatment-related complications were analyzed in this study.

Results:

There were eight female and five male patients with a mean age of 12 years (ranging from 4 to 8 years). Pain was the common presenting feature in all cases. Focal neurological deficits corresponding to the anatomical location was seen in six patients. These 13 cases were distributed anatomically as four cases involving the cloves, two cases with occipital bone and lobe involvement, one case of parietal bone and lobe involvement, and six cases of spinal involvement. Surgery was performed in all cases where gross total excision (Ozge C, Calikoglu M, Cinel L, Apaydin FD, Ozgür ES. Massive pleural effusion in an 18-year-old girl with Ewing sarcoma. Can Respir J 2004;11:363-5), near-total excision, and subtotal excision was achieved in these 13 cases (Steinbok P, Flodmark O, Norman MG, Chan KW, Fryer CJ. Primary Ewing’s sarcoma of the base of the skull. Neurosurgery 1986;19:104-7). Subsequently all cases underwent multiagent chemoradiotherapy. Postsurgery pain subsided in 12 (92%) of patients. Ten patients maintained or improved motor function. In seven cranial cases and in six spinal cases, four cases showed improvement whereas three (23%) had deterioration of motor function.

Conclusions:

Surgical outcome of SSES in short-term follow-up is good with current recommended management regimen of maximum excision followed by chemo and radiotherapy. However, metastasis is not uncommon.

Osteosarcoma, Chondrosarcoma, and Chordoma

Osteosarcoma (OS), chondrosarcoma, and chordoma are characterized by multiple challenges to the investigator, clinician, and patient. One consequence of their rarity among sarcomas, as well as their biologic and clinical heterogeneity, is that management guidelines are inadequate to inform the range of individual patient-treatment decisions from diagnosis, approaches to surgery, chemotherapy, radiotherapy, treatment of recurrence, palliative care, and quality of survivorship. Of high-grade sarcomas, OSs are among the most curable, with more than two-thirds of patients with localized disease likely to achieve long-term survival. Neoadjuvant chemotherapy comprising cisplatin, doxorubicin, and methotrexate with intercalated surgery is the standard of care for resectable OS in those younger than 40 years. Outcomes for OS presenting with unresectable metastases or recurrent disease, or in those older than 40 years are generally poor. Overall results have improved little for all patients with OS, and new treatments are needed. Surgical resection remains the cornerstone of management for chondrosarcoma and chordoma. However, the application of new biologic insights to therapeutic development indicates that improved treatments may soon be routine for patients with chondrosarcoma and chordoma for whom surgery alone is inadequate. For all these uncommon diseases, patients should be offered specialist expert care delivered by experienced multidisciplinary teams in high-volume centers.