***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: Background The reported data on surgery plus radiotherapy for retroperitoneal soft tissue sarcomas ( RPS ) have been mostly from retrospective studies . We evaluated the long-term outcome of patients with operable RPS who were treated with protocol -based preoperative radiotherapy followed by complete surgical resection . Methods Data from two prospect i ve trials that included preoperative radiotherapy and surgery for patients with radiographically resectable RPS were combined to define long-term relapse rates and survival . Results Seventy-two patients with intermediate- or high- grade RPS were treated with preoperative radiotherapy ( median dose , 45 Gy ; range , 18.0–50.4 Gy ) . Fifty-four patients ( 75 % ) had primary RPS , whereas 18 ( 25 % ) had recurrent disease . The median tumor size was 15.5 cm . Sixty-four patients completed the planned preoperative radiotherapy ; 57 ( 89 % ) underwent laparotomy with curative intent , and 54 ( 95 % ) had a macroscopically complete ( R0 or R1 ) resection . With a median follow-up of 40.3 months , 28 patients ( 52 % ) who received preoperative radiotherapy and underwent a macroscopically complete resection had recurrences . For the 54 patients who underwent R0 or R1 resection after preoperative radiotherapy , the 5-year local recurrence – free , disease-free , and overall survival rates were 60 % , 46 % , and 61 % , respectively . The median overall survival has not been reached ( > 60 months ) . Conclusions Patients with intermediate- or high- grade RPS treated with preoperative radiotherapy plus complete resection had a median survival > 60 months . This compares favorably to historical data for similar patients treated with surgery alone Complete surgical resection is the most effective modality for the treatment of retroperitoneal sarcomas . Previous studies of all types of retroperitoneal sarcomas have not shown a survival benefit of incomplete resection over no resection . Because death often occurs as a result of local progression in retroperitoneal liposarcomas ( RPLS ) , it is possible that incomplete resection may be beneficial in this histologic type . In this study we have sought to determine the clinical outcomes in patients with incompletely resected and unresected RPLS with the aim of defining patients who may benefit from palliative resection .  From a prospect i ve clinical data base 55 patients with incompletely resected ( n = 43 ) or unresected ( n = 12 ) RPLS were identified between 1982 and 1999 . Statistical analyses were performed using the log-rank test and Kaplan-Meier estimates with disease-specific survival as the primary end point . Variables studied included age , gender , recurrent versus primary disease , tumor grade , and tumor size . The patient population consisted of 34 men and 21 women with a mean age of 61 + /- 14 ( SD ) years . The median time to death was 10 months ( range 1 to 83 months ) with a median followup of 12 months ( range 1 to 60 months ) for survivors . Partial resection  was an independent factor for increased survival as compared with exploration or biopsy only ( median survival 26 versus 4 months , p < 0.0001 ) . Of patients who received incomplete resections , locally recurrent presentation ( n = 19 ) versus primary disease ( n = 24 ) was a negative prognostic variable ( median survival 17 versus 46 months , p = 0.009 ) . Successful palliation of symptoms was achieved in 24 of 32 patients ( 75 % ) with preoperative symptoms . In select patients with unresectable RPLS , incomplete surgical resection can provide prolongation in survival and successful symptom palliation . Most likely to benefit are those patients presenting with primary tumors , suggesting that surgical resection should be attempted in the majority of patients PURPOSE The primary objective of this phase I trial was to define the maximum-tolerated dose of continuous-infusion doxorubicin administered with st and ard preoperative radiation for patients with localized , potentially resectable soft tissue sarcomas of the extremities or body wall . PATIENTS AND METHODS Twenty-seven patients with radiographically resectable intermediate- or high- grade soft tissue sarcomas were treated .  Preoperative external-beam radiation was administered in 25 2-Gy fractions ( total dose , 50 Gy ) . Concurrent continuous-infusion doxorubicin was administered by an initial bolus ( 4 mg/m(2 ) ) and subsequent 4-day continuous infusion ( 12.5 , 15.0 , 17.5 , or 20.0 mg/m(2)/wk ) . Radiographic restaging was performed 4 to 7 weeks after chemoradiation , and patients with localized disease underwent surgical resection . RESULTS Chemoradiation was completed as an outpatient procedure in 25 patients ( 93 % ) . The maximum-tolerated dose of continuous-infusion doxorubicin combined with st and ard preoperative radiation was 17.5 mg/m(2)/wk ; at this dose level , seven ( 30 % ) of 23 patients had grade 3 dermatologic toxicity . Macroscopically complete resection ( R0 or R1 ) was performed in all 26 patients who underwent surgery . Among 22 patients who were treated with doxorubicin 17.5/mg/m(2)/wk with concurrent radiation and subsequent surgery , 11 patients ( 50 % ) had 90 % or greater tumor necrosis , including two patients who had complete pathologic responses . CONCLUSION Preoperative doxorubicin-based chemoradiation appears safe and feasible . The maximum-tolerated dose of continuous-infusion doxorubicin with st and ard preoperative radiation was 17.5 mg/m(2)/wk . Pathologic response rates with this regimen are encouraging Background Surgical resection alone does not cure the majority of patients with retroperitoneal sarcoma ( RPS ) . We evaluated the effects of preoperative external-beam radiotherapy ( XRT ) and postoperative brachytherapy ( BT ) combined with complete surgical resection . Methods Fifty-five patients with primary or locally recurrent RPS judged to be resectable were entered onto a trial of combined therapy and observed prospect ively . Forty-six patients underwent  complete gross resection  with curative intent . Of these , 41 patients completed preoperative XRT and 23 patients received BT . Outcome measures were treatment toxicity , overall survival , and disease-free survival ( DFS ) . Results Preoperative XRT was very well tolerated and was associated with Radiation Therapy Oncology Group acute toxicity scores of ≤2 in all patients . Acute postoperative and BT-related toxicity result ed in modified RTOG scores of ≥3 in 39.1 % ( 18 of 46 ) of patients . Late toxicity was associated with death in 4.3 % ( 2 of 46 ) and with life-threatening illness in 2.2 % ( 1 of 46 ) of patients , all of whom had been treated with BT to the upper abdomen . The 2-year overall survival and DFS for resected RPS were 88 % and 80 % , respectively . Significantly better 2-year DFS was achieved in patients with primary RPS and in those with low- grade tumors ( 93 % and 95 % , respectively ) . Conclusions The initial results of combined therapy are promising . Although preoperative XRT was very well tolerated , BT to the upper abdomen was associated with substantial toxicity . Our current protocol includes selective application of BT to the lower abdomen only Retroperitoneal sarcomas ( RPSs ) are rare tumors with poor survival rates due to difficult resectability and high local and distant recurrence rates . Preoperative radiation therapy appears to have dosimetric advantages to utilize the tumor as a tissue exp and er to limit exposure of small bowel to higher radiation doses Retroperitoneal sarcomas ( RPS ) are rare tumours that typically present late and carry a poor prognosis even following grossly complete resection . In an attempt to improve the outlook for patients with RPS , sarcoma specialists have employed various adjuvant therapies , including extermal beam radiation , intraoperative radiation , brachyradiation and systemic chemotherapy . This article review s the presentation and prognosis of RPS , and focuses on the results of new treatment strategies compared with conventional management . A Medline search of the English literature was performed to identify all retrospective and prospect i ve reports relating to the management of adult RPS published since 1980 . Series that did not analyse RPS separately from other intra-abdominal or extra-abdominal sarcomas or other malignancies were excluded , and information on investigation , presentation , prognostic factors , treatment and outcome was extracted from the remaining reports . Survival and local control data were collected from reports that contained at least 30 cases of RPS ( n = 31 ) . While surgical resection remains the cornerstone of treatment for RPS , the majority of patients will relapse and die from sarcoma within 5 years of resection . Adjuvant radiation may improve these results , but further trials are required to definitively demonstrate its benefit . Possible reasons for the failure of conventional treatment are discussed , and alternative strategies design ed to overcome these obstacles are presented PURPOSE Few published studies have analyzed risk factors for sarcoma-specific death . We developed and internally vali date d a nomogram that combines the factors to predict the probability of 12-year sarcoma-specific death using a data base of 2,136 prospect ively followed adult patients treated at a single institution . PATIENTS AND METHODS Nomogram predictor variables included age at diagnosis , tumor size ( < or = 5 , 5 to 10 , or > 10 cm ) , histologic grade ( high or low ) , histologic subtype ( fibrosarcoma , leiomyosarcoma , liposarcoma , malignant fibrous histiocytoma , malignant peripheral nerve tumor , synovial , or other ) , depth ( superficial or deep ) , and site ( upper extremity , lower extremity , visceral , thoracic or trunk , retrointraabdominal , or head or neck ) . Death from sarcoma or treatment complication was the predicted end point . Three prediction methods were compared , Kaplan-Meier analysis of all possible subsets , recursive partitioning , and Cox proportional hazards regression analysis . The concordance index was used as an accuracy measure with bootstrapping to correct for optimistic bias . RESULTS Sarcoma-specific death at 12 years was 36 % ( 95 % confidence interval , 33 % to 39 % ) . The bootstrap-corrected concordance indices were as follows : Kaplan-Meier , 0.69 ; recursive partitioning , 0.74 ; and Cox regression , 0.77 . A nomogram was drawn on the basis of the Cox regression model . This nomogram was internally vali date d using bootstrapping and shown to have excellent calibration . CONCLUSION A nomogram has been developed to predict 12-year sarcoma-specific death . This tool may be useful for patient counseling , follow-up scheduling , and clinical trial eligibility determination Thirty-five patients with surgically resected sarcomas of the retroperitoneum were enrolled in a prospect i ve , r and omized , clinical trial comparing 20-Gy intraoperative radiotherapy in combination with postoperative low-dose ( 35- to 40-Gy ) external-beam radiotherapy with postoperative high-dose ( 50- to 55-Gy ) external-beam radiotherapy alone . Chemotherapy with doxorubicin hydrochloride , cyclophosphamide ( anhydrous ) , and methotrexate sodium was used for a portion of the trial . Fifteen patients who received intraoperative radiotherapy and 20 control patients were followed up for a minimum of 5 years ( median follow-up , 8 years ) . Median survival times were similar for the group that received intraoperative radiotherapy ( 45 months ) and the control group ( 52 months ) . There were no indications of benefit from adjunctive chemotherapy . The number of locoregional recurrences was significantly lower among those who received intraoperative radiotherapy ( six of 15 ) than control patients ( 16 of 20 ) . Patients who received intraoperative radiotherapy had fewer complications of disabling radiation-related enteritis ( two of 15 ) than control patients ( 10 of 20 ) , but radiation-related peripheral neuropathy was more frequent among those who received intraoperative radiotherapy ( nine of 15 ) than among control patients ( one of 20 ) PURPOSE Retroperitoneal soft tissue sarcomas are rare tumors . Studies characterizing long-term follow-up and patterns of recurrence are limited . The purpose of this analysis is to identify patterns of recurrence and prognostic factors associated with long-term survival after resection of retroperitoneal soft tissue sarcomas .  METHODS Between July 1 , 1982 , and June 30 , 1990 , 198 adult patients were identified from our prospect i ve soft tissue sarcoma data base carrying the diagnosis of retroperitoneal soft tissue sarcoma who were eligible for > or = 5 years of follow-up . Of these , 48 patients ( 25 % ) were documented to be alive > or = 5 years from the time of operation . Statistical analysis was by log-rank or Wilcoxon test for univariate analysis . Multivariate analysis was by the Cox model . RESULTS The recurrence rate during the follow-up period was approximately 5 % per year from the time of initial operation . Of the patients who were disease-free for > or = 5 years from initial surgery 
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The authors concluded that there is good evidence from multiple single-institutions studies that RT improves the LCR in patients with retroperitoneal sarcoma .
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