Intraoperative electron-beam therapy for primary and recurrent retroperitoneal soft-tissue sarcoma

Intraoperative radiotherapy might not serve as a standard therapy for retroperitoneal liposarcoma: insights from a population-based propensity score-matched study

BACKGROUND

Difficulty in achieving complete resection leads to a poor prognosis for retroperitoneal soft tissue sarcoma, hence emphasizing the significance of adjuvant treatment. The benefit of preoperative radiotherapy for retroperitoneal liposarcoma was initially demonstrated by the STRASS trial. However, the impact of intraoperative radiotherapy (IORT) on retroperitoneal liposarcoma remains unexplored.

METHOD

Patients with retroperitoneal liposarcoma were identified in the Surveillance, Epidemiology, and End Results (SEER) database, treated between 2000 and 2019. Subsequently, a 1:1 propensity score-matched (PSM) analysis was conducted based on variables identified from a multivariate analysis. T-tests were used to assess differences in normally distributed continuous variables, while the rank-sum test was applied to variables that did not follow a normal distribution. The chi-squared test was utilized to evaluate differences in categorical variables. Ultimately, survival analysis was performed using SPSS to evaluate patient prognosis.

RESULT

A total of 2129 patients with retroperitoneal liposarcoma were included in our study. Age, sex, histology, grading, chemotherapy, and tumor size as independent prognostic risk factors for these patients through multivariate Cox regression analysis. Subsequently, 66 patients were included in the survival analysis through PSM, with 33 patients receiving IORT. Finally, the survival analysis revealed that there was no difference in overall survival among patients with retroperitoneal liposarcoma, regardless of whether they received IORT or not (p= 0.711).

CONCLUSION

As an exploratory study, our findings suggest that patients may not derive benefit from intraoperative radiotherapy. These observations are intended to lay the groundwork for future prospective clinical studies.

Radiotherapy and surgery remain effective treatment options for retroperitoneal MPNST: a retrospective study based on SEER database

Introduction

The proportion of retroperitoneal malignant peripheral nerve sheath tumours (RMPNST) in retroperitoneal tumors is less than 5%, but the mortality rate is very high. However, there is no relevant research focused on RMPNST only.

Methods

We retrospectively analyzed data from the SEER database of patients with primary RMPNST from 2000 to 2019, by leveraging the advantages of the Seer database, we can explore the prognosis of such rare diseases. Kaplan-Meier method was used to construct the survival curve, and cox regression model was used to analyze the factors affecting the prognosis of patients. In addition, a model was developed to distinguish high-risk and low-risk patients.

Results

This study included a total of 52 patients, with a median survival time of 39 months (95% CI 12.740-65.260) and a 5-year survival rate of 44.2% (95% CI 0.299-0.565). Radiotherapy (p = 0.004, OR: 1.475, 95% CI 0.718-3.033), metastasis disease (p = 0.002, OR: 5.596, 95% CI 2.449-47.079) and surgery (p = 0.003, OR: 5.003, 95% CI 0.011-0.409) were associated with overall survival (OS). The 5-year distant metastasis rate was 36% (95% CI 0.221-0.499). We used the above risk factors to separate patients into high and low groups and evaluate the results through the receiver operating characteristic (ROC) curve. This model is beneficial for guiding the selection of treatment strategies.

Conclusion

The majority of RMPNST patients have a good prognosis after surgery, and the establishment of high-low group is helpful for clinical decision-making.

Progress in Retroperitoneal Sarcoma Management: Surgical and Radiotherapy Approaches

Surgical resection is the cornerstone of curative treatment for retroperitoneal sarcomas (RPS), aiming for complete excision, yet the complexity of RPS with its proximity to vital structures continues to lead to high local recurrence rates after surgery alone. Thus, the role of radiotherapy (RT) continues to be refined to improve local control, which remains an important goal to prevent RPS recurrence. The recently completed global randomized trial to evaluate the role of surgery with and without preoperative RT - STRASS1, did not demonstrate a significant overall benefit for neoadjuvant RT based on the pre-specified definition of abdominal recurrence-free survival, however, sensitivity analysis using a standard definition of local recurrence and analysis of outcomes by compliance to the RT protocol suggests histology-specific benefit in well- and some de-differentiated liposarcomas. Ultimately, multidisciplinary collaboration and personalized approaches that consider histological sarcoma types and patient-specific factors are imperative for optimizing the therapeutic strategy in the management of RPS.

Comparative In Silico Analysis of Ultra-Hypofractionated Intensity-Modulated Photon Radiotherapy (IMRT) Versus Intensity-Modulated Proton Therapy (IMPT) in the Pre-Operative Treatment of Retroperitoneal Sarcoma

BACKGROUND

While pre-operative radiation did not improve abdominal recurrence-free survival for retroperitoneal sarcoma (RPS) in the randomized STRASS trial, it did reduce rates of local recurrence. However, the risk of toxicity was substantial and the time to surgery was prolonged. A combination of hypofractionation and proton therapy may reduce delays from the initiation of radiation to surgery and limit the dose to surrounding organs at risk (OARs). We conducted a dosimetric comparison of the pre-operative ultra-hypofractionated intensity-modulated photon (IMRT) and proton radiotherapy (IMPT).

METHODS

Pre-operative IMRT and IMPT plans were generated on 10 RPS patients. The prescription was 25 Gy radiobiological equivalents (GyEs) (radiobiological effective dose of 1.1) to the clinical target volume and 30 GyEs to the margin at risk, all in five fractions. Comparisons were made using student T-tests.

RESULTS

The following endpoints were significantly lower with IMPT than with IMRT: mean doses to liver, bone, and all genitourinary and gastrointestinal OARs; bowel, kidney, and bone V5-V20; stomach V15; liver V5; maximum doses to stomach, spinal canal, and body; and whole-body integral dose.

CONCLUSIONS

IMPT maintained target coverage while significantly reducing the dose to adjacent OARs and integral dose compared to IMRT. A prospective trial treating RPS with pre-operative ultra-hypofractionated IMPT at our institution is currently being pursued.

Midterm Results of High-Dose-Rate Intraoperative Brachytherapy in the Treatment of Soft Tissue Sarcomas

INTRODUCTION

According to the literature only sparse data are available on the use of high-dose-rate intraoperative brachytherapy (IOHDR-BT) as a boost to external-beam irradiation (EBRT) in combination with a wide resection in patients with high-grade soft tissue sarcomas (STS).

MATERIALS AND METHODS

Applying a retrospective study design, we investigated all patients who between 2010 and 2016 underwent marginal resection of a high-grade STS and intraoperative radiotherapy, followed by EBRT. We included only patients with a traceable follow-up time of at least two years. Of 89 patients, 35 met our inclusion criteria and showed an average follow-up of four years.

RESULTS

We found an overall 2-year local control rate of 94.3%. The local recurrence rate for R0 resections was 6%, whereas recurrences occurred in 13% of R1 resections and in 100% of R2 resections. One affected patient received only intraoperative radiotherapy. The recurrence rate by tumour entity was 36% for LPS, 11% for myxofibrosarcoma and 17% for undifferentiated pleomorphic sarcoma.

CONCLUSION

The treatment regimen consisting of limb-preserving surgery, IORT and pre- or postoperative radiotherapy consistently shows excellent local control rates.

Preoperative Dose-Escalated Intensity-Modulated Radiotherapy (IMRT) and Intraoperative Radiation Therapy (IORT) in Patients with Retroperitoneal Soft-Tissue Sarcoma: Final Results of a Clinical Phase I/II Trial

BACKGROUND

To report the final results of a prospective, one-armed, single-center phase I/II trial (NCT01566123).

METHODS

Between 2007 and 2017, 37 patients with primary or recurrent (N = 6) retroperitoneal sarcomas were enrolled. Treatment included preoperative IMRT of 45-50 Gy with a simultaneous integrated boost of 50-56 Gy, surgery and IORT. The primary endpoint was local control (LC) at 5 years. The most common histology was dedifferentiated liposarcoma (51%), followed by leiomyosarcoma (24%) and well-differentiated liposarcoma (14%). The majority of lesions were high-grade (FNCLCC G1: 30%, G2: 38%, G3: 27%, two missing). Five patients were excluded from LC analysis per protocol.

RESULTS

The minimum follow-up of the survivors was 62 months (median: 109; maximum 162). IORT was performed for 27 patients. Thirty-five patients underwent gross total resection; the pathological resection margin was mostly R+ (80%) and, less often, R0 (20%). We observed 10 local recurrences. The 5-year LC of the whole cohort was 59.6%. Eleven patients received a dose > 50 Gy plus IORT boost; LC was 64.8%; the difference, however, was not significant (p = 0.588). Of 37 patients, 15 were alive and 22 deceased at the time of final analysis. The 5-year OS was 59.5% (68.8% per protocol).

CONCLUSIONS

The primary endpoint of a 5-year LC of 70% was not met. This might be explained by the inclusion of recurrent disease and the high rate of G3 lesions and leiomyosarcoma, which have been shown to profit less from radiotherapy. Stratification by grading and histology should be considered for future studies.

Radiation Therapy for Retroperitoneal Sarcomas: A Strass-Ful Situation

Locoregional recurrence (LRR) is the predominant pattern of relapse and often the cause of death in patients with retroperitoneal sarcomas (RPS). As a result, reducing LRR is a critical objective for RPS patients. However, unlike soft tissue sarcomas (STS) of the superficial trunk and extremity where the benefits of radiation therapy (RT) are well-established, the role of RT in the retroperitoneum remains controversial. Historically, preoperative or postoperative RT, either alone or in combination with intraoperative radiation (IORT), was commonly justified for RPS based on extrapolation from the superficial trunk and extremity STS literature. However, long-awaited results were recently published from the European Organization for Research and Treatment of Cancer (EORTC) STRASS study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS; there was no statistical difference in the primary endpoint of abdominal recurrence-free survival. However, several subset analyses and study limitations complicate the interpretation of the results. This review explores and contextualizes the body of evidence regarding RT's role in managing RPS.

Retroperitoneal Sarcomas: a Current Review on Management

Retroperitoneal sarcomas are heterogeneous tumours with variable disease biology and outcomes. The prognosis is primarily related to tumour histology and grade as well as the ability to achieve margin negative resection. Surgery involves compartment or contiguous organ resection to achieve the above goal. Careful utilization of neoadjuvant and adjuvant strategies like radiotherapy and/or chemotherapy can lead to improvement in margin status, thereby contributing to better local control and possibly reducing systemic dissemination. Use of targeted therapies has paved newer pathways of treatment integration centred on molecular and genetic targets. The aim of this review is to update the reader on all aspects of retroperitoneal sarcoma management including emphasis on pertinent and landmark trials in this regard.

Treatment for local control of retroperitoneal and pelvis sarcomas: A review of the literature

Retroperitoneal and pelvis sarcomas are uncommon tumors for which complete surgical resection is the mainstay of treatment. However, achieving complete gross resection with microscopically negative margins is challenging, and local recurrence rates can be high. Patients often succumb to uncontrolled local disease. Radiation therapy offers a potential means for sterilizing microscopic residual disease, although its use continues to be controversial. Chemotherapy alone or in combination with radiation continues to be investigated as an adjunct to surgery, along with immunotherapy and targeted therapies. In this review, we discuss the current management of retroperitoneal and pelvis sarcomas, focusing on studies of surgery and radiation therapy to maximize local control.

Retroperitoneal and Mesenteric Liposarcomas

Retroperitoneal liposarcomas are a rare entity and are comprised mostly of the well-differentiated and dedifferentiated subtypes. Eight-year survival ranges from 30% to 80% depending on histologic subtype and grade. Surgery is the cornerstone of treatment and compartment resection is the current standard. Mesenteric liposarcomas are extremely rare and comprise more high-grade lesions, with poorer prognosis of 50% 5-year overall survival. They are managed with a similar aggressive surgical approach. This review presents the current management of retroperitoneal and mesenteric liposarcomas.

Soft Tissue Sarcoma, Version 2.2022, NCCN Clinical Practice Guidelines in Oncology

Soft tissue sarcomas (STS) are rare malignancies of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Soft Tissue Sarcoma provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as retroperitoneal/intra-abdominal STS, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis and treatment of retroperitoneal/intra-abdominal STS, outlines treatment recommendations, and reviews the evidence to support the guidelines recommendations.

Role of Radiation Therapy for Newly Diagnosed Retroperitoneal Sarcoma

OPINION STATEMENT

Soft tissue sarcomas (STS) are rare, aggressive, and heterogenous tumors, comprising approximately 1% of adult cancers with over 50 different subtypes. The mainstay of treatment for retroperitoneal sarcomas (RPS) includes surgical resection. The addition of radiation therapy (RT), either preoperatively or postoperatively, has been used to potentially decrease the risk of local recurrence. The recently published results from STRASS (EORTC-STBSG 62092-22092), which randomized patients to receive or not receive preoperative radiation, indicate no abdominal recurrence-free survival benefit (primary endpoint) nor overall survival benefit to date from the addition of preoperative RT prior to surgical resection in patients with RPS. Keeping in mind caveats of subgroup analyses, the data show a significant reduction in local recurrence with radiation therapy in resected patients and non-significant trends toward improved abdominal recurrence-free survival in all patients and improved local control and abdominal recurrence-free survival in patients with liposarcoma and low-grade sarcoma. Given the high rate of local failure with surgery alone, it is possible that higher RT dose and/or selective RT dose painting may improve outcomes. Prior to treatment, the authors encourage multidisciplinary review and discussion of management options at a sarcoma center for patients with RPS. Selective use of RT may be considered for patients at high risk of local recurrence.

Multimodale Therapie primärer, nicht metastasierter retroperitonealer Sarkome

Weichteilsarkome sind eine heterogene Gruppe von Tumoren mesenchymalen Ursprungs, die teilweise ein sehr unterschiedliches biologisches Verhalten zeigen. Retroperitoneale Weichteilsarkome (RSTS) machen 10 – 15% aller Weichteilsarkome aus. Behandlungsempfehlungen für RSTS basieren auf vorrangig retrospektiven Analysen mit geringer Evidenz, die in dieser Übersichtsarbeit dargestellt werden. Zentraler Pfeiler in der Behandlung des lokalisierten, nicht metastasierten RSTS ist die chirurgische Resektion im Sinne einer Kompartment-Resektion. Ziel ist dabei immer die allseitig vollständige Tumorentfernung mit mikroskopisch freien Resektionsrändern. Ist das Erreichen dieses Behandlungsziels mit der alleinigen Kompartment-Resektion fraglich oder besteht eine hohe Wahrscheinlichkeit für eine lokale Tumorrekurrenz bei high-grade Sarkomen, so sollte eine neoadjuvante Bestrahlung, gegebenenfalls mit intraoperativem Boost, im Rahmen eines multimodalen Therapieansatzes durchgeführt werden. Die in Analogie zu den Extremitätensarkomen zu favorisierende Anthrazyklin-basierte Chemotherapie hat ihren Stellenwert vorrangig in der Adjuvanz. Auch wenn ein onkologischer Vorteil durch eine adjuvante Chemotherapie für RSTS bisher nicht nachgewiesen ist, sollte bei high-grade Sarkomen die Indikation diskutiert werden. In Kenntnis der unterschiedlichen Krankheitsverläufe werden zunehmend an die unterschiedlichen histologischen Subtypen adaptierte Therapiekonzepte diskutiert und in Studien untersucht. Valide Empfehlungen lassen sich jedoch bisher nicht ableiten. Die Behandlung von RSTS-Patienten wie überhaupt von Patienten mit Sarkomen in Zentren mit entsprechender Expertise ist mit einer signifikanten Verbesserung der Prognose assoziiert und ist unbedingt anzustreben.

Neoadjuvant Radiotherapy-Related Wound Morbidity in Soft Tissue Sarcoma: Perspectives for Radioprotective Agents

Historically, patients with localized soft tissue sarcomas (STS) of the extremities would undergo limb amputation. It was subsequently determined that the addition of radiation therapy (RT) delivered prior to (neoadjuvant) or after (adjuvant) a limb-sparing surgical resection yielded equivalent survival outcomes to amputation in appropriate patients. Generally, neoadjuvant radiation offers decreased volume and dose of high-intensity radiation to normal tissue and increased chance of achieving negative surgical margins-but also increases wound healing complications when compared to adjuvant radiotherapy. This review elaborates on the current neoadjuvant/adjuvant RT approaches, wound healing complications in STS, and the potential application of novel radioprotective agents to minimize radiation-induced normal tissue toxicity.

Intraoperative radiation therapy (IORT) for soft tissue sarcoma - ESTRO IORT Task Force/ACROP recommendations

PURPOSE

To describe guidelines for the use of intraoperative radiation therapy (IORT) in the treatment of soft-tissue sarcomas (STS).

METHODS

A panel of experts in the field performed a systematic literature review, supplemented their clinical experience and developed recommendations for the use of IORT in the treatment of STS.

RESULTS

Based on the evidence from the systematic literature review and the clinical experience of the panel members, recommendations regarding patient selection, incorporation into multimodal treatment concepts and the IORT procedure itself are made. The rationale for IORT in extremity and retroperitoneal STS is summarized and results of the major series in terms of patient and treatment characteristics, oncological outcome and toxicity are presented. We define surgical factors, volumes for irradiation, technical requirements, dose prescription, recording and reporting, treatment delivery and care during the course of IORT covering the main IORT techniques used for the treatment of STS. In extremity STS, evidence originates from a few small prospective and mainly from retrospective single centre studies. Based on those reports, IORT containing-approaches result in very high local control rates with low rates of acute and late toxicity. In retroperitoneal sarcomas, evidence is derived from one prospective randomized trial, a few prospective and a large number of retrospective studies. The randomized trial compared IORT combined with moderate doses of postoperative external-beam radiation therapy (EBRT) to high-dose postoperative EBRT alone after gross total resection, clearly favouring the IORT-containing approach. These results have been confirmed by the prospective and retrospective studies, which similarly showed high local control rates with acceptable toxicity, mainly favouring combinations of preoperative EBRT and IORT.

CONCLUSIONS

IORT-containing approaches result in high rates of local control with low to acceptable toxicity rates. Based on the available evidence, we made recommendations for the use of IORT in STS. Clinicians and researchers are encouraged to use these guidelines in clinical routine as well as in the design of future trials.

Retroperitoneal soft-tissue sarcomas: Radiotherapy experience from a tertiary cancer center and review of current evidence

BACKGROUND

Surgery remains to be the main therapeutic approach for retroperitoneal sarcomas (RPS) although evidence supports that complementary radiotherapy increases local-control and survival. We present a multidisciplinary management and experience of a tertiary cancer center in the treatment of RPS and analyze current evidence of radiotherapy efficacy.

PATIENTS AND METHODS

We retrospectively reviewed 19 patients with primary or relapsed RPS treated between November 2009 and October 2018. Multidisciplinary approach comprised complete resection in 15 patients (79%) achieving resection R0 in 11 patients (58%), R1 in 4 patients (21%) and R2 in 2 patients (10%). Seven patients (37%) underwent a preoperative radiation (PRORT), 10 patients (53%), post-operative radiation (PORT) and 2 patients (10%), received radiotherapy exclusively. Ten patients (53%) received adjuvant chemotherapy.

RESULTS

With a median follow-up of 24 months (2-114 months), actuarial rates of loco-regional relapse free survival (LRFS) at 1, 2 and 3 years were 77%, 77% and 67%, respectively. Actuarial rates of distant-metastases-free survival (DMFS), disease-free survival (DFS) and overall survival (OS) at 1, 2 and 3 years were 100%, 100% and 80% for DMFS; 94%, 77% and 67% for DFS and 100%, 91% and 91% for OS, respectively. Only surgical margins (negative vs. positive) showed significance for 3y-LRFS: 100% vs. 34.3%, p = 0.018. Treatment tolerance was acceptable with no acute or late toxicity higher than grade 2.

CONCLUSIONS

Complementary radiotherapy appears to be useful and well tolerated for the multidisciplinary management of RPS. Presence of positive surgical margins seems to be the most relevant prognostic factor through the follow-up.

Neoadjuvant and adjuvant strategies in retroperitoneal sarcoma

Extended surgery remains the mainstay of treatment in retroperitoneal sarcoma, although conflicting data exist on the benefit of neoadjuvant and adjuvant therapies, particularly with regard to tumour grade and histological type. Experience of radiotherapy and chemotherapy in extremity soft tissue sarcoma can inform treatment strategies, however these data cannot be universally extrapolated to the retroperitoneum where disease biology and anatomical considerations are different. The present review sets a historical context before discussing recent evidence and on-going multi-centre trials in retroperitoneal sarcoma. Promising data on histologically- and molecularly-targeted chemotherapy are discussed and the need for centralisation of retroperitoneal sarcoma services in order to facilitate large international collaborative trials is emphasised.

Retroperitoneal Soft Tissue Sarcoma: Prognostic Factors and Therapeutic Approaches

Aims and Background

Retroperitoneal sarcomas are a rare group of malignant soft tissue tumors with a generally poor prognosis. The aim of the study was to assess clinical, pathological and treatment-related factors affecting prognosis in patients with retroperitoneal sarcomas.

Methods and Study Design

The hospital records of 73 patients who underwent surgical exploration at our unit for primary retroperitoneal sarcomas between 1984 and 2003 were reviewed. Factors influencing overall and disease-free survival were analyzed for all patients and for those who underwent complete surgical resection.

Results

The complete resectability rate was 69.8% (51/73). Operative mortality and morbidity rates were 2.7% and 21.9%, respectively. For patients who underwent complete resection, the 5-year survival rate was 58.3%, whereas it was 0% in cases of incomplete or no resection (P <0.001). Local recurrence rate was 37.2%. Incomplete gross surgical resection and microscopic infiltration of margins were the most important independent predictors of a poor prognosis.

Conclusions

The present study confirmed the importance of an aggressive surgical management for retroperitoneal sarcomas to offer these patients the best chance for long-term survival.

Intraoperative radiotherapy: review of techniques and results

Intraoperative radiotherapy (IORT) is a technique that involves precise delivery of a large dose of ionising radiation to the tumour or tumour bed during surgery. Direct visualisation of the tumour bed and ability to space out the normal tissues from the tumour bed allows maximisation of the dose to the tumour while minimising the dose to normal tissues. This results in an improved therapeutic ratio with IORT. Although it was introduced in the 1960s, it has seen a resurgence of popularity with the introduction of self-shielding mobile linear accelerators and low-kV IORT devices, which by eliminating the logistical issues of transport of the patient during surgery for radiotherapy or building a shielded operating room, has enabled its wider use in the community.

Electrons, low-kV X-rays and HDR brachytherapy are all different methods of IORT in current clinical use. Each method has its own unique set of advantages and disadvantages, its own set of indications where one may be better suited than the other, and each requires a specific kind of expertise.

IORT has demonstrated its efficacy in a wide variety of intra-abdominal tumours, recurrent colorectal cancers, recurrent gynaecological cancers, and soft-tissue tumours. Recently, it has emerged as an attractive treatment option for selected, early-stage breast cancer, owing to the ability to complete the entire course of radiotherapy during surgery. IORT has been used in a multitude of roles across these sites, for dose escalation (retroperitoneal sarcoma), EBRT dose de-escalation (paediatric tumours), as sole radiation modality (early breast cancers) and as a re-irradiation modality (recurrent rectal and gynaecological cancers).

This article aims to provide a review of the rationale, techniques, and outcomes for IORT across different sites relevant to current clinical practice.

Intraoperative radiation therapy (IORT) in soft-tissue sarcoma

Soft-tissue sarcoma (STS) represent a rare tumor entity, accounting for less than 1% of adult malignancies. The cornerstone of curative intent treatment is surgery with free margins, although the extent of the surgical approach has been subject to change in the last decades. Multimodal approaches usually including radiation therapy have replaced extensive surgical procedures in order to preserve functionality while maintaining adequate local control. However, the possibility to apply adequate radiation doses by external beam radiation therapy (EBRT) can be limited in some situation especially in case of directly adjacent organs at risk with low radiation tolerance. Application of at least a part of the total dose via intraoperative radiation therapy (IORT) with a single fraction during the surgical procedure may overcome those limitations, because radiosensitive structures can be moved out of the radiation field resulting in reduced toxicity while the enhanced biological effectivity of the high single dose improves local control. The current review summarizes rationale, techniques, oncological and functional outcomes including possible pitfalls and associated toxicities based on the published literature for IORT focusing on extremity and retroperitoneal STS. In extremity STS, combination of limb-sparing surgery, IORT and pre- or postoperative EBRT with moderate doses consistently achieved excellent local control rates at least comparable to approaches using EBRT alone but usually including patient cohorts with higher proportions of unfavourable prognostic factors. Further on, IORT containing approaches resulted in very high limb preservation rates and good functional outcome, probably related to the smaller high dose volume. In retroperitoneal STS, the combination of preoperative EBRT, surgery and IORT consistently achieved high local control rates which seem superior to surgery alone or surgery with EBRT at least with regard to local control and in some reports even to overall survival. Further on, preoperative EBRT in combination with IORT seems to be superior to the opposite combination with regard to local control and toxicity. No major differences in wound healing disturbances or postoperative complication rates can be observed with IORT compared to non-IORT containing approaches. Neuropathy of major nerves remains a dose limiting toxicity requiring dose restrictions or exclusion from target volume. Gastrointestinal structures and ureters should be excluded from the IORT area whenever possible and the IORT volume should be restricted to the available minimum. Nevertheless, IORT represents an ideal boosting method if combined with EBRT and properly executed by experiences users which should be further evaluated preferably in prospective randomized trials.

Effect of intraoperative radiotherapy in the treatment of retroperitoneal sarcoma

BACKGROUND

Current National Comprehensive Cancer Network guidelines for the treatment of retroperitoneal sarcomas (RPS) endorse surgical resection, but the role of radiotherapy (RT) is less clear. We investigate the utilization and benefits of intraoperative RT (IORT) in the treatment of RPS.

METHODS

We queried the Surveillance, Epidemiology and End Results (SEER) database (1988-2013) for the utilization of IORT and perioperative external beam RT (EBRT) in patients who underwent surgical resection of RPS. Groups were defined as any IORT (aIORT), IORT alone (IORT-), IORT with EBRT (IORT+) and preoperative and/or postoperative EBRT without IORT (EBRT). Demographics, tumor characteristics, extent of disease, and survival were compared between groups.

RESULTS

We identified 908 patients with RPS who underwent surgical resection with perioperative RT. Demographics of age, sex, and race were similar between groups. There was no difference in baseline tumor characteristics of mean size, tumor grade, or histological subtype between groups. A higher percentage of patients receiving aIORT had tumors >20 cm in size, and extension beyond local tissues. Liposarcoma and leiomyosarcoma were the most common subtypes overall and in each subgroup. Patients with liposarcoma undergoing IORT and EBRT (IORT+) demonstrated a survival benefit over both IORT alone (IORT-) and EBRT alone.

CONCLUSION

IORT was used infrequently for RPS but generated equivalent outcomes compared to EBRT, despite being utilized more often for larger tumors and those with peri-tumoral soft-tissue invasion. Patients with the most common subtype (liposarcoma) may benefit from combination IORT with adjuvant EBRT versus other regimens.

Micro-invasive surgery combined with intraoperative radiotherapy for the treatment of spinal metastasis

PURPOSE

This is a retrospective analysis of the strategy and clinical results of surgery combined with intraoperative radiotherapy (IORT) to treat spinal metastases.

METHODS

We delivered tumour-conformal IORT in 40 patients with 52 metastatic vertebrae based on our surgical classification system. The strategies were evaluated with respect to neurologic function and spinal stability. The EORTC QLQ-BM22, visual analogue scale (VAS) and the Frankel Scale were used to assess quality of life, pain and neurologic function. Local control was evaluated every 3 months using X-rays and MRI.

RESULTS

Micro-invasive IORT was performed in 42 vertebrae (80.8%), and open surgery with IORT was performed in 10 vertebrae (19.2%). Single-level, 2-level and 3-level IORT was performed in 30, 8 and 2 cases, respectively. The delivered dose was 9.2 ± 3.6 Gy (8-15 Gy) with a depth of 10.1 ± 2.1 mm. The actual IORT treatment time was 5 min and 16 s. The follow-up period was 6-23 months (mean: 12.5 months). The local control rate was 92.3%. The EORTC QLQ-BM22 scores showed that patients had significant improvements in pain location, degree and function after treatment (P < 0.01). Thirty-five patients (89.7%) achieved pain relief throughout the follow-up period. VAS scores were significantly reduced by 3.4 points 3 months after treatment. Neurological function was improved in 7 patients (87.5%). No radiation-related complications were observed.

CONCLUSIONS

Surgery combined with tumour-conformal IORT can effectively relieve pain, achieve good local control and improve QOL.

Cytoreductive Surgery plus Hyperthermic Intraperitoneal Chemotherapy for Management of Peritoneal Sarcomatosis: A Preliminary Single-Center Experience from Saudi Arabia

Aim. To report our preliminary single-center experience with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC) for management of peritoneal sarcomatosis (PS). Methods. Eleven patients were retrospectively analyzed for perioperative details. Results. Cytoreduction completeness (CC-0/1) was achieved in all patients with median peritoneal cancer index (PCI) of 14 ± 8.9 (range: 3-29). Combination cisplatin + doxorubicin HIPEC chemotherapy was used in 6 patients. Five patients received intraoperative radiation therapy (IORT). The median operative time, estimated blood loss, and hospital stay were 8 ± 1.4 hours (range: 6-10), 1000 ± 250 mL (range: 700-3850), and 11 ± 2.4 days (range: 7-15), respectively. Major postoperative Clavien-Dindo grade III/IV complications occurred in 1 patient and none developed HIPEC chemotherapy-related toxicities. The median overall survival (OS) and disease-free survival (DFS) after CRS + HIPEC were 28.3 ± 3.2 and 18.0 ± 4.0 months, respectively. The median follow-up time was 12 months (range: 6-33). Univariate analysis of several prognostic factors (age, gender, PS presentation/pathology, CC, PCI, HIPEC chemotherapy, and IORT) did not demonstrate statistically significant differences of OS and DFS. Conclusion. CRS + HIPEC appear to be feasible, safe, and offer survival oncological benefits. However, definitive conclusions cannot be deduced.

Long-term outcomes in treatment of retroperitoneal sarcomas: A 15 year single-institution evaluation of prognostic features

BACKGROUND

Retroperitoneal sarcomas are connective tissue tumors arising in the retroperitoneum. Surgical resection is the mainstay of treatment. Debate has arisen over extent of resection, changes in histological classification/grading, and interest in incorporating radiotherapy. Therefore, we reviewed our institution's experience to evaluate prognostic factors.

METHODS

Retrospective chart review of all primary RPS patients at Johns Hopkins Hospital from 1994 to 2010. Histologic diagnosis and grading were re-evaluated with current criteria. Prognostic factors for survival, and recurrence were assessed.

RESULTS

One hundred thirty-one primary RPS patients met inclusion criteria. Median survival for patients who undergo en-bloc resection to negative margins (R0/R1) is 81.7 months. Surgical margins and grade were the most important factors for survival along with age, gender, presence of metastases and resection of ≥5 organs. Five-year survival for R0/R1 resection was 60%, similar to compartmental resection. Radiotherapy significantly decreased local recurrence (P = 0.026) on multivariate analysis. Grade in leiomyosarcomas and dedifferentiation in liposarcomas dictated patterns of local versus distal recurrence.

CONCLUSIONS

En bloc surgical resection to R0/R1 margins remains the cornerstone of therapy and provides comparable outcomes to compartmental resections. Grade remains important for prognosis, and histology dictates recurrence patterns. Radiotherapy appears promising for local control and warrants further investigation. J. Surg. Oncol. 2016;114:56-64. © 2016 Wiley Periodicals, Inc.

[Intra-abdominal and retroperitoneal sarcomas]

Sarcomas are a heterogeneous group of rare tumors that originate from mesenchymal tissue. Radical R0 resection is the only curative option, which is especially challenging in retroperitoneal or intra-abdominal sarcomas. This article describes the current data on optimal interdisciplinary and primarily surgical therapy of visceral sarcomas. Surgical resection of retroperitoneal sarcomas must be performed according to the principle of radical compartmental resection, i.e. with complete excision of the mass along with en bloc visceral resection of adjacent organs and tissues covering the tumor, which also contains any not obviously infiltrated neighboring organs. The main objective is R0 resection without opening the tumor capsule in the primary operation because the best long-term results can be achieved with this approach.

Retroperitoneal liposarcoma: a comprehensive review

Retroperitoneal liposarcomas are rare mesenchymal tumors of the retroperitoneum that typically present with advanced disease and often carry a poor prognosis. Because of their rarity and anatomic location, these malignant tumors can cause a diagnostic dilemma and present several therapeutic challenges. They are usually associated with a high rate of recurrence despite grossly complete resection, thus requiring long-term and often indefinite follow-up. Relevant data on this topic was procured and synthesized with the aid of a comprehensive Medline search in addition to oncologic, pathologic, urologic, radiologic, and surgical literature review on retroperitoneal sarcomas. This article provides an in-depth review into the natural history, pathology, clinical manifestations, and prognostic features of retroperitoneal liposarcomas. It also discusses the reliability of diagnostic procedures and novel curative approaches that are currently being evaluated for the disease.

Successful salvage treatment of myxoid liposarcoma with multiple peritoneal seeding using helical tomotherapy-based intraperitoneal radiotherapy: a case report

BACKGROUND

Myxoid liposarcoma is the most common soft-tissue sarcoma that metastasizes to the peritoneal cavity. Recently, an advanced intensity-modulated radiotherapy, known as helical tomotherapy, has been introduced to improve target coverage, while reducing normal tissue radiation. Here, we report a case of myxoid liposarcoma with multiple peritoneal seeding that was chemotherapy-refractory, but was successfully salvaged by helical tomotherapy-based intraperitoneal radiotherapy.

CASE PRESENTATION

A 71-year-old East-Asian male was initially diagnosed with myxoid liposarcoma in his left thigh by excision. Six years later, the patient underwent a left pneumonectomy for metastatic myxoid liposarcoma in the left lung. Since then, the patient was treated with two segmental resections, and multiple lines of chemotherapy, for repeated recurrences in the peritoneal cavity. The patient underwent intraperitoneal radiotherapy followed by tumor boost radiotherapy, as salvage treatment for chemotherapy-resistant metastatic peritoneal myxoid liposarcoma. The prescribed dose was 24 Gy delivered in 15 fractions of 1.6 Gy over 3 weeks, followed by a 16 Gy boost dose administered in eight fractions of 2 Gy, to multifocal peritoneal lesions. A positron emission tomography scan obtained 8 weeks after completion of radiotherapy, showed a complete metabolic response of metastatic peritoneal lesions. Radiotherapy was well tolerated, without any side effects. In a computed tomography scan obtained 20 weeks after completion of radiotherapy, most of the peritoneal metastatic lesions had disappeared, except for two small residual nodules.

CONCLUSION

This case suggests that low fraction-sized intraperitoneal radiotherapy (1.6 Gy administered once daily), followed by a focal boost using helical tomotherapy, is a feasible treatment without side effects. It produced an excellent tumor response, and durable intraperitoneal control for metastatic peritoneal myxoid liposarcoma.

Intraoperative radiotherapy in early stage breast cancer: potential indications and evidence to date

Following early results of recent studies of intraoperative radiotherapy (IORT) in the adjuvant treatment of patients with early breast cancer, the clinical utility of IORT is a subject of much recent debate within the breast oncology community. This review describes the intraoperative techniques available, the potential indications and the evidence to date pertaining to local control and toxicity. We also discuss any implications for current practice and future research.

Role of radiation therapy for non-extremity soft tissue sarcomas

BACKGROUND

Negative surgical margins are uncommon for non-extremity soft tissue sarcomas. Radiation therapy is usually recommended to improve local control; however, appropriate RT dosing is challenging due to nearby dose-limiting normal structures.

MATERIAL AND METHODS

Comprehensive literature search using PubMed (March 2014).

RESULTS

Data suggest radiation therapy is an important modality in maximizing local tumor control in non-extremity sarcomas.

CONCLUSION

The literature supports the use of RT to improve local control for non-extremity soft tissue sarcomas.

Clinical phase I/II trial to investigate preoperative dose-escalated intensity-modulated radiation therapy (IMRT) and intraoperative radiation therapy (IORT) in patients with retroperitoneal soft tissue sarcoma: interim analysis

Background

To report an unplanned interim analysis of a prospective, one-armed, single center phase I/II trial (NCT01566123).

Methods

Between 2007 and 2013, 27 patients (pts) with primary/recurrent retroperitoneal sarcomas (size > 5 cm, M0, at least marginally resectable) were enrolled. The protocol attempted neoadjuvant IMRT using an integrated boost with doses of 45–50 Gy to PTV and 50–56 Gy to GTV in 25 fractions, followed by surgery and IOERT (10–12 Gy). Primary endpoint was 5-year-LC, secondary endpoints included PFS, OS, resectability, and acute/late toxicity. The majority of patients showed high grade lesions (FNCLCC G1:18%, G2:52%, G3:30%), predominantly liposarcomas (70%). Median tumor size was 15 cm (6–31).

Results

Median follow-up was 33 months (5–75). Neoadjuvant IMRT was performed as planned (median dose 50 Gy, 26–55) in all except 2 pts (93%). Gross total resection was feasible in all except one patient. Final margin status was R0 in 6 (22%) and R1 in 20 pts (74%). Contiguous-organ resection was needed in all grossly resected patients. IOERT was performed in 23 pts (85%) with a median dose of 12 Gy (10–20 Gy).

We observed 7 local recurrences, transferring into estimated 3- and 5-year-LC rates of 72%. Two were located outside the EBRT area and two were observed after more than 5 years. Locally recurrent situation had a significantly negative impact on local control. Distant failure was found in 8 pts, resulting in 3- and 5-year-DC rates of 63%. Patients with leiomyosarcoma had a significantly increased risk of distant failure. Estimated 3- and 5-year-rates were 40% for PFS and 74% for OS. Severe acute toxicity (grade 3) was present in 4 pts (15%). Severe postoperative complications were found in 9 pts (33%), of whom 2 finally died after multiple re-interventions. Severe late toxicity (grade 3) was scored in 6% of surviving patients after 1 year and none after 2 years.

Conclusion

Combination of neoadjuvant IMRT, surgery and IOERT is feasible with acceptable toxicity and yields good results in terms of LC and OS in patients with high-risk retroperitoneal sarcomas. Long term follow-up seems mandatory given the observation of late recurrences. Accrual of patients will be continued with extended follow-up.

Trial registration

NCT01566123.

Preoperative intensity modulated radiation therapy for retroperitoneal sarcoma

The use of intensity modulated radiation therapy (IMRT) has allowed for the administration of high doses to retroperitoneal sarcomas (RSTS) while limiting toxicity to adjacent organs. The purpose of our study is to assess the outcome and toxicities of patients with RSTS treated with neo-adjuvant external beam radiation (EBRT) therapy using IMRT. This is a retrospective study of 21 patients treated with preoperative IMRT for primary or recurrent RSTS between 2005 and 2011. Overall survival (OS) and local recurrence free survival (LRFS) were computed using the Kaplan-Meier method (log-rank test). Acute and chronic toxicities were assessed using the CTCAE v. 3 criteria. The actuarial 2 and 3-year OS was 66% for both and the 5-year OS was 51%. As for LRFS it was 57% at 2 and 3-year and 51% for the 5-year LRFS. Factors predictive for local control were microscopically negative margins (p = 0.022), a median tumor diameter <15 cm (p = 0.007) and pathology of liposarcoma (p = 0.021). Furthermore, patients treated for recurrent disease fared worse (p = 0.04) in local control than patients treated for primary disease. As for OS, patients treated for Grade 1 histology had a better outcome (p 5 0.05). EBRT was generally well tolerated. Acute gastrointestinal (GI) Grade 1 or 2 toxicities occurred in 33% of patients and one patient had unexplained post-radiation Grade 2 fever that resolved after tumor resection. As for chronic toxicities 24% of our patients presented Grade 1 GI toxicity and one patient presented Grade 3 small bowel stenosis not clearly due to radiation toxicity. Despite the location and volume of the tumors treated, preoperative IMRT was very well tolerated in our patients with retroperitoneal sarcoma. Unfortunately local recurrences remain common and dose escalation is to be considered.

The role of radiation in retroperitoneal sarcomas

OPINION STATEMENT

Retroperitoneal sarcomas form a group of rare malignancies that require expertise in every aspect of management. Patients benefit from referral to cancer centers that can provide comprehensive, multidisciplinary, oncologic management. The role of radiation in retroperitoneal sarcoma management is, appropriately, the subject of considerable controversy due to the absence of high-level evidence proving its efficacy. Nonetheless, the preponderance of available data suggests that radiation therapy likely improves local control and, in some settings, may favorably impact resectability and survival. These outcome observations coupled with the lower doses (45-54 Gy) and normal tissue displacement characteristic of preoperative radiation therapy leads us to favor preoperative radiotherapy followed by oncologic resection for most retroperitoneal sarcomas. This strategy appears to provide the highest chance of safe and successful delivery of multimodal therapy, which can otherwise be hindered by postoperative complications as a result of technically challenging surgery and normal tissue radiation dose tolerances. Dose-escalation and selective integrative boosts to "at-risk" margins are attractive strategies that merit, and arguably require, further clinical evaluation. We believe that postoperative radiotherapy should be reserved for very high-risk cases and should be treated to a dose of ≥60 Gy respecting normal tissue dose tolerances. An additional approach that we consider in the postoperative setting is close surveillance with consideration of preoperative radiotherapy at recurrence before repeat surgical resection. Highly conformal radiotherapy techniques, such as IMRT with image guidance, should be employed to minimize dose to normal tissues and thereby allow delivery of efficacious radiation doses. If feasible, referral to a treatment facility with proton beam therapy should be discussed with the patient, especially if normal tissue dose constraints cannot be met using IMRT/IGRT. Participation in prospective studies should be highly encouraged.

Prognostic value of external beam radiation therapy in patients treated with surgical resection and intraoperative electron beam radiation therapy for locally recurrent soft tissue sarcoma: a multicentric long-term outcome analysis

BACKGROUND

A joint analysis of data from centers involved in the Spanish Cooperative Initiative for Intraoperative Electron Radiotherapy was performed to investigate long-term outcomes of locally recurrent soft tissue sarcoma (LR-STS) patients treated with a multidisciplinary approach.

METHODS AND MATERIALS

Patients with a histologic diagnosis of LR-STS (extremity, 43%; trunk wall, 24%; retroperitoneum, 33%) and no distant metastases who underwent radical surgery and intraoperative electron radiation therapy (IOERT; median dose, 12.5 Gy) were considered eligible for participation in this study. In addition, 62% received external beam radiation therapy (EBRT; median dose, 50 Gy).

RESULTS

From 1986 to 2012, a total of 103 patients from 3 Spanish expert IOERT institutions were analyzed. With a median follow-up of 57 months (range, 2-311 months), 5-year local control (LC) was 60%. The 5-year IORT in-field control, disease-free survival (DFS), and overall survival were 73%, 43%, and 52%, respectively. In the multivariate analysis, no EBRT to treat the LR-STS (P=.02) and microscopically involved margin resection status (P=.04) retained significance in relation to LC. With regard to IORT in-field control, only not delivering EBRT to the LR-STS retained significance in the multivariate analysis (P=.03).

CONCLUSION

This joint analysis revealed that surgical margin and EBRT affect LC but that, given the high risk of distant metastases, DFS remains modest. Intensified local treatment needs to be further tested in the context of more efficient concurrent, neoadjuvant, and adjuvant systemic therapy.

Current concepts in multimodality therapy for retroperitoneal sarcoma

Radical surgical resection currently represents the most effective therapy for patients with retroperitoneal sarcoma. Unfortunately, margin-negative resection often mandates extirpation of multiple retroperitoneal viscera, and such operations are nonetheless fraught with high rates of locoregional recurrence. In an attempt to improve local control and ultimately survival, adjuvant strategies of radiation and chemotherapy have been increasingly employed, with promising results. To date, however, the rarity of the disease has limited large, prospective studies investigating the efficacy of these adjuvant modalities. In this article, we review the current literature pertaining to the diagnosis, staging and treatment of retroperitoneal sarcoma and demonstrate the critical need for future large, multi-institutional studies to advance our knowledge of this uncommon disease.

Present status and future directions of intraoperative radiotherapy

In this Review, we summarise recent published work on the use of intraoperative radiotherapy to treat common tumour sites in the primary or recurrent setting. Techniques, radiobiology, and the physics of intraoperative radiotherapy are also explored. Disease sites discussed in this Review include head and neck cancer, breast cancer, sarcoma, gastrointestinal cancer, genitourinary cancer, gynaecological cancer, thoracic cancer, and palliative applications.

Clinical and technical characteristics of intraoperative radiotherapy. Analysis of the ISIORT-Europe database

BACKGROUND

A joint analysis of clinical data from centres within the European section of the International Society of Intraoperative Radiation Therapy (ISIORT-Europe) was undertaken in order to define the range of intraoperative radiotherapy (IORT) techniques and indications encompassed by its member institutions.

MATERIALS AND METHODS

In 2007, the ISIORT-Europe centres were invited to record demographic, clinical and technical data relating to their IORT procedures in a joint online database. Retrospective data entry was possible.

RESULTS

The survey encompassed 21 centres and data from 3754 IORT procedures performed between 1992 and 2011. The average annual number of patients treated per institution was 42, with three centres treating more than 100 patients per year. The most frequent tumour was breast cancer with 2395 cases (63.8 %), followed by rectal cancer (598 cases, 15.9 %), sarcoma (221 cases, 5.9 %), prostate cancer (108 cases, 2.9 %) and pancreatic cancer (80 cases, 2.1 %). Clinical details and IORT technical data from these five tumour types are reported.

CONCLUSION

This is the first report on a large cohort of patients treated with IORT in Europe. It gives a picture of patient selection methods and treatment modalities, with emphasis on the main tumour types that are typically treated by this technique and may benefit from it.

Effect of radiation therapy on survival in surgically resected retroperitoneal sarcoma: a propensity score-adjusted SEER analysis

BACKGROUND

Currently no prospective randomized trial has measured the efficacy of radiation therapy for resected retroperitoneal sarcomas (RPS). Our objective was to determine the effect of radiation therapy on disease-specific and overall survival between propensity score-matched surgically resected RPS patients using the Surveillance, Epidemiology, and End Results (SEER) database.

PATIENTS AND METHODS

The study population consisted of patients with histologically confirmed RPS who underwent surgical resection between 1988 and 2006. Exclusion criteria included multiple malignancies, distant metastasis, and unknown grade or stage. Cox modeling was used to determine covariate associations with disease-specific survival. Propensity score methods were used to perform survival analysis in patients who received radiation matched with patients who underwent surgery alone.

RESULTS

Prior to matching, there were 762 patients (558 surgery only, 204 surgery with radiation). Factors independently associated with radiation therapy were age (P = 0.037), geographic region (P = 0.041), grade (P = 0.047), stage (P = 0.003), and surgery type (P = 0.01). Cox modeling demonstrated that age, sex, grade, and stage were independently associated with survival. Propensity scoring (309 matched pairs) and survival analysis using Kaplan-Meier methods demonstrated no difference between propensity score-matched patients receiving radiation therapy and those who did not (P = 0.35).

CONCLUSION

At present, SEER patients with surgically resected RPS who received radiation therapy did not demonstrate survival benefit.

Aggressive local treatment containing intraoperative radiation therapy (IORT) for patients with isolated local recurrences of pancreatic cancer: a retrospective analysis

Background

To evaluate the use of intraoperative radiation therapy (IORT) in the multimodality treatment of patients with isolated local recurrences of pancreatic cancer.

Methods

We retrospectively analyzed 36 patients with isolated local recurrences of pancreatic cancer who have been treated with a combination of surgery, IORT and EBRT. Median time from initial treatment to recurrence was 20 months. All patients were surgically explored. In 18 patients a gross total resection was achieved, whereas the other half received only debulking or no resection at all. All patients received IORT with a median dose of 15 Gy. Additional EBRT was applied to 31 patients with a median dose of 45 Gy, combined with concurrent, mainly gemcitabine-based chemotherapy.

Results

Median follow-up in surviving patients was 23 months. Local progression was found in 6 patients after a median time of 17 months, resulting in estimated 1- and 2-year local control rates of 91% and 67%, respectively. Distant failure was observed in 23 patients, mainly in liver or peritoneal space. The median estimated progression-free survival was 9 months with 1- and 2-year rates of 40% and 26%, respectively. We found an encouraging estimated median overall survival of 19 months, transferring into 1- and 2-year rates of 66% and 45%. Notably 6 of 36 patients (17%) lived for more than 3 years. Severe postoperative complications were found in 3 and chemoradiation-related grade III toxicity in 6 patients. No severe IORT related toxicity was observed.

Conclusion

Combination of surgery, IORT and EBRT in patients with isolated local recurrences of pancreatic cancer resulted in encouraging local control and overall survival in our cohort with acceptable toxicity. Our approach seems to be superior to palliative chemotherapy or chemoradiation alone and should be further investigated in a prospective setting specifically addressing isolated local recurrences of pancreatic cancer.

A clinical phase I/II trial to investigate preoperative dose-escalated intensity-modulated radiation therapy (IMRT) and intraoperative radiation therapy (IORT) in patients with retroperitoneal soft tissue sarcoma

Background

The current standard treatment, at least in Europe, for patients with primarily resectable tumors, consists of surgery followed by adjuvant chemotherapy. But even in this prognostic favourable group, long term survival is disappointing because of high local and distant failure rates. Postoperative chemoradiation has shown improved local control and overalls survival compared to surgery alone but the value of additional radiation has been questioned in case of adjuvant chemotherapy. However, there remains a strong rationale for the addition of radiation therapy considering the high rates of microscopically incomplete resections after surgery. As postoperative administration of radiation therapy has some general disadvantages, neoadjuvant and intraoperative approaches theoretically offer benefits in terms of dose escalation, reduction of toxicity and patients comfort especially if hypofractionated regimens with highly conformal techniques like intensity-modulated radiation therapy are considered.

Methods/Design

The NEOPANC trial is a prospective, one armed, single center phase I/II study investigating a combination of neoadjuvant short course intensity-modulated radiation therapy (5 × 5 Gy) in combination with surgery and intraoperative radiation therapy (15 Gy), followed by adjuvant chemotherapy according to the german treatment guidelines, in patients with primarily resectable pancreatic cancer. The aim of accrual is 46 patients.

Discussion

The primary objectives of the NEOPANC trial are to evaluate the general feasibility of this approach and the local recurrence rate after one year. Secondary endpoints are progression-free survival, overall survival, acute and late toxicity, postoperative morbidity and mortality and quality of life.

Trial registration

NCT01372735.

A clinical phase I/II trial to investigate preoperative dose-escalated intensity-modulated radiation therapy (IMRT) and intraoperative radiation therapy (IORT) in patients with retroperitoneal soft tissue sarcoma

BACKGROUND

Local control rates in patients with retroperitoneal soft tissue sarcoma (RSTS) remain disappointing even after gross total resection, mainly because wide margins are not achievable in the majority of patients. In contrast to extremity sarcoma, postoperative radiation therapy (RT) has shown limited efficacy due to its limitations in achievable dose and coverage. Although Intraoperative Radiation Therapy (IORT) has been introduced in some centers to overcome the dose limitations and resulted in increased outcome, local failure rates are still high even if considerable treatment related toxicity is accepted. As postoperative administration of RT has some general disadvantages, neoadjuvant approaches could offer benefits in terms of dose escalation, target coverage and reduction of toxicity, especially if highly conformal techniques like intensity-modulated radiation therapy (IMRT) are considered.

METHODS/DESIGN

The trial is a prospective, one armed, single center phase I/II study investigating a combination of neoadjuvant dose-escalated IMRT (50-56 Gy) followed by surgery and IORT (10-12 Gy) in patients with at least marginally resectable RSTS. The primary objective is the local control rate after five years. Secondary endpoints are progression-free and overall survival, acute and late toxicity, surgical resectability and patterns of failure. The aim of accrual is 37 patients in the per-protocol population.

DISCUSSION

The present study evaluates combined neoadjuvant dose-escalated IMRT followed by surgery and IORT concerning its value for improved local control without markedly increased toxicity.

TRIAL REGISTRATION

NCT01566123.

Full-dose adjuvant postoperative radiation therapy for retroperitoneal sarcomas

OBJECTIVES

To categorize sites of recurrence of retroperitoneal sarcomas (RPS) and correlate to clinical treatment volumes of postoperative radiation therapy (PORT) with or without intraoperative radiation therapy (IORT).

METHODS

A retrospective review of patients with RPS who received PORT between 1990 and 2008 was done. Tumor recurrences were subdivided as local tumor bed, regional adjacent retroperitoneal fascial tissues, peritoneal diffuse seeding, and distant metastases.

RESULTS

PORT was given to 33 patients, 20 of whom also received IORT. Local recurrences appeared in 4 (12%) cases. Regional recurrences appeared in 8 (26%) cases, including 5 with in-field recurrence and 3 with edge-of-field recurrence. Edge-of-field recurrences developed in 3 of 11 (27%) patients whose clinical presentation was local recurrence compared with none of 20 patients whose clinical presentation was a primary tumor (P=0.037). Late grades 3 to 4 gastrointestinal toxicities appeared in 1 of 10 (10%) patients who received intensity-modulated radiation therapy (IMRT) with a minimum 15-month follow-up compared with 4 of 15 (27%) patients who received standard RT.

CONCLUSIONS

Use of techniques such as IORT and IMRT can deliver a dose of approximately 60 Gy to the tumor bed and 44 to 51 Gy to the surrounding retroperitoneal fascial planes. Acute and late gastrointestinal toxicities were less frequent with IMRT compared with conventional PORT with IORT. These results may provide the basis for comparison of various adjuvant therapy strategies for RPS. As radiation therapy is a loco-regional treatment, results should be reported by tumor recurrence subtypes of local, regional, peritoneal, and distant.

Radiotherapy and surgery-an indispensable duo in the treatment of retroperitoneal sarcoma

The authors undertook a systematic review to designate the role that radiotherapy (RT) might play in the treatment of retroperitoneal sarcomas. Correlating with recent literature, the objective of this review was to evaluate whether there was enough evidence for the authors to develop an institutional treatment protocol concerning the use of RT in the treatment of retroperitoneal sarcoma. Furthermore, this was a call for surgeons to talk to radiation oncologists before performing surgery. The 2 objectives of this review were: 1) to determine the benefit of RT in terms of local control and/or survival in the treatment of retroperitoneal sarcomas and 2) to discover the optimal timing of RT in the treatment sequence. A computerized literature search was performed in the PubMed database, the Cochrane Library database, and reference lists; and journals also were searched by hand to identify all retrospective and prospective reports published since 1998 relating to RT treatment of adult retroperitoneal sarcoma. Mainly, analyses were sought that were based on a 5-year local control rate (LCR), 5-year disease-free survival, and 5-year overall survival (OS). If only 2 years follow-up were available, then the authors also noted this outcome. Toxicity data were collected and analyzed separately. The synthesis of the literature was based on 9 prospectively nonrandomized studies and 10 retrospective studies that, together, reviewed a total of 1426 patients. The 5-year LCR varied from 27% to 62%, and the results from other reports fell in between those values. The 5-year OS rate ranged from 12% to 90%, and complete resection and tumor grade were the most important prognostic factors in most studies. This review resulted in 7 recommendations concerning the use of RT in the treatment of retroperitoneal sarcoma. The authors concluded that there is good evidence from multiple single-institutions studies that RT improves the LCR in patients with retroperitoneal sarcoma. Until now, there has not been a translation of this approach into survival benefit. The current results indicated that preoperative external-beam RT followed by radical surgery seems to be the preferred sequence, and adding intraoperative RT is a safe procedure for dose escalation in the upper abdomen.

Heavy charged particle radiobiology: using enhanced biological effectiveness and improved beam focusing to advance cancer therapy

Ionizing radiation causes many types of DNA damage, including base damage and single- and double-strand breaks. Photons, including X-rays and γ-rays, are the most widely used type of ionizing radiation in radiobiology experiments, and in radiation cancer therapy. Charged particles, including protons and carbon ions, are seeing increased use as an alternative therapeutic modality. Although the facilities needed to produce high energy charged particle beams are more costly than photon facilities, particle therapy has shown improved cancer survival rates, reflecting more highly focused dose distributions and more severe DNA damage to tumor cells. Despite early successes of charged particle radiotherapy, there is room for further improvement, and much remains to be learned about normal and cancer cell responses to charged particle radiation.