***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The dose-response for local tumor control after  stereotactic radiotherapy of 92 pulmonary tumors ( 36 NSCLC and 56 metastases ) was evaluated . Short course irradiation of 1 - 8 fractions with different fraction doses was used . After a median follow-up of 14 months ( 2 - 85 months ) 11 local recurrences were observed with significant advantage for higher doses . When normalization to a biologically effective dose ( BED ) is used a dose of 94Gy at the isocenter and 50Gy at the PTV-margin are demonstrated to give 50 % probability of tumor control ( TCD50 ) . Multivariate analysis revealed the dose at the PTV-margin as the only significant factor for local control PURPOSE Surgical resection is st and ard therapy in stage I non-small-cell lung cancer ( NSCLC ) ; however , many patients are inoperable due to comorbid diseases . Building on a previously reported phase I trial , we carried out a prospect i ve phase II trial using stereotactic body radiation therapy ( SBRT ) in this population . PATIENTS AND METHODS Eligible patients included clinical ly staged T1 or T2 ( < or = 7 cm ) , N0 , M0 , biopsy-confirmed NSCLC . All patients had comorbid medical problems that precluded lobectomy .  SBRT treatment dose was 60 to 66 Gy total in three fractions during 1 to 2 weeks . RESULTS All 70 patients enrolled completed therapy as planned and median follow-up was 17.5 months . The 3-month major response rate was 60 % . Kaplan-Meier local control at 2 years was 95 % . Altogether , 28 patients have died as a result of cancer ( n = 5 ) , treatment ( n = 6 ) , or comorbid illnesses ( n = 17 ) . Median overall survival was 32.6 months and 2-year overall survival was 54.7 % . Grade 3 to 5 toxicity occurred in a total of 14 patients . Among patients experiencing toxicity , the median time to observation was 10.5 months . Patients treated for tumors in the peripheral lung had 2-year freedom from severe toxicity of 83 % compared with only 54 % for patients with central tumors . CONCLUSION High rates of local control are achieved with this SBRT regimen in medically inoperable patients with stage I NSCLC . Both local recurrence and toxicity occur late after this treatment . This regimen should not be used for patients with tumors near the central airways due to excessive toxicity PURPOSE A Phase I dose escalation study of stereotactic body radiation therapy to assess toxicity and local control rates for patients with medically inoperable Stage I lung cancer . METHODS AND MATERIAL S All patients had non-small-cell lung carcinoma , Stage T1a or T1b N0 , M0 . Patients were immobilized in a stereotactic body frame and treated in escalating doses of radiotherapy beginning at 24 Gy total ( 3 x 8 Gy fractions ) using 7 - 10 beams . Cohorts were dose escalated by 6.0 Gy total with appropriate observation periods . RESULTS The maximum tolerated dose was not achieved in the T1 stratum ( maximum dose = 60 Gy ) , but within the T2 stratum , the maximum tolerated dose was realized at 72 Gy for tumors larger than 5 cm . Dose-limiting toxicity included predominantly bronchitis , pericardial effusion , hypoxia , and pneumonitis . Local failure occurred in 4/19 T1 and 6/28 T2 patients . Nine local failures occurred at doses < or = 16 Gy and only 1 at higher doses . Local failures occurred between 3 and 31 months from treatment . Within the T1 group , 5 patients had distant or regional recurrence as an isolated event , whereas 3 patients had both distant and regional recurrence . Within the T2 group , 2 patients had solitary regional recurrences , and the 4 patients who failed distantly also failed regionally . CONCLUSIONS Stereotactic body radiation therapy seems to be a safe , effective means of treating early-stage lung cancer in medically inoperable patients . Excellent local control was achieved at higher dose cohorts with apparent dose-limiting toxicities in patients with larger tumors PURPOSE Routine assessment was made of tumor metabolic activity as measured by 18F-fluorodeoxyglucose ( FDG ) positron emission tomography ( PET ) in Stage I non-small-cell lung cancer ( NSCLC ) . This report describes PET correlates prospect ively collected after stereotactic body radiotherapy ( SBRT ) for patients with medically inoperable NSCLC . METHODS AND MATERIAL S 14 consecutive patients with medically inoperable Stage I NSCLC were enrolled . All patients received SBRT to 60 - 66 Gy in three fractions . Patients underwent serial planned FDG-PET/computed tomography fusion imaging before SBRT and at 2 , 26 , and 52 weeks after SBRT . RESULTS With median follow-up of 30.2 months , no patients experienced local failure . One patient developed regional failure , 1 developed distant failure , and 1 developed a second primary . The median tumor maximum st and ardized uptake value ( SUV(max ) ) before SBRT was 8.70 . The median SUV(max ) values at 2 , 26 , and 52 weeks after SBRT were 6.04 , 2.80 , and 3.58 , respectively . Patients with low pre-SBRT SUV were more likely to experience initial 2-week rises in SUV , whereas patients with high pre-SBRT SUV commonly had SUV declines 2 weeks after treatment ( p = 0.036 ) . Six of 13 patients had primary tumor SUV(max ) > 3.5 at 12 months after SBRT but remained without evidence of local disease failure on further follow-up . CONCLUSIONS A substantial proportion of patients may have moderately elevated FDG-PET SUV(max ) at 12 months without evidence of local failure on further follow-up . Thus , slightly elevated PET SUV(max ) should not be considered a surrogate for local treatment failure . Our data do not support routine serial FDG-PET/computed tomography for follow-up of patients receiving SBRT for Stage I NSCLC PURPOSE In a previously reported r and omized Southeastern Cancer Study Group ( SECSG ) trial , three cycles of chemotherapy were found to be equivalent to four cycles in patients with favorable-prognosis germ-cell cancer . We have conducted a follow-up analysis of patients treated at Indiana University ( Indianapolis , IN ) to compare long-term survival between the two groups and to examine factors associated with survival . PATIENTS AND METHODS Sixty-nine patients with minimal-stage and 49 patients with moderate-stage disseminated germ-cell tumors were r and omized to either three or four courses of bleomycin , etoposide , and cisplatin ( BEP ) administered every 3 weeks . Median follow-up time is 10.1 years ( range , 7 months to 12.6 years ) . Ninety-two percent of patients have an actual follow-up time of > 5 years , and 97.5 % of patients have an actual follow-up time of > 3 years . RESULTS Survival analysis shows no significant difference between the two treatment groups in terms of overall ( P = .80 ) or disease-free ( P = .93 ) survival . Several clinical variables were examined by univariate analysis ; only serum human chorionic gonadotropin ( HCG ) had an impact on survival . There were two disease-related deaths in 104 patients with HCG < or = 1,000 mIU/mL and five disease-related deaths in 14 patients with HCG greater than 1,000 mIU/mL ( P < .001 ) . Ninety-eight percent ( 95 % CI , 95.2 to 100 ) of patients with favorable prognosis germ-cell tumor with an initial HCG of < or = 1,000 mIU/mL are alive without evidence of disease at 5 + years . CONCLUSION With long-term follow-up , there is no statistically significant difference in survival between three or four cycles of BEP chemotherapy in patients with favorable prognosis germ-cell carcinoma . Serum HCG elevation of greater than 1,000 mIU/mL is a significant predictor of poor outcome in patients with otherwise good-risk disease Background : The purpose of this study was to report initial results of a phase I study using single-fraction stereotactic radiotherapy ( RT ) in patients with inoperable lung tumors . Methods : Eligible patients included those with inoperable T1 - 2N0 non-small cell lung cancer ( NSCLC ) or solitary lung metastases . Treatments were delivered by means of the CyberKnife . All patients underwent computed tomography-guided metallic fiducial placement in the tumor for image-guided targeting .  Nine to 20 patients were treated per dose cohort starting at 15 Gy/fraction followed by dose escalation of 5 to 10 Gy to a maximal dose of 30 Gy/fraction . A minimal 3-month period was required between each dose level to monitor toxicity . Results : Thirty-two patients ( 21 NSCLC and 11 metastatic tumors ) were enrolled . At 25 Gy , pulmonary toxicity was noted in patients with prior pulmonary RT and treatment volumes greater than 50 cc ; therefore , dose escalation to 30 Gy was applied only to unirradiated patients and treatment volume less than 50 cc . Ten patients received doses less than 20 Gy , 20 received 25 Gy , and two received 30 Gy . RT-related complications were noted for doses greater than 25 Gy and included four cases of grade 2 to 3 pneumonitis , one pleural effusion , and three possible treatment-related deaths . The 1-year freedom from local progression was 91 % for dose greater than 20 Gy and 54 % for dose less than 20 Gy in NSCLC ( p = 0.03 ) . NSCLC patients had significantly better freedom from relapse ( p = 0.003 ) and borderline higher survival than those with metastatic tumors ( p = 0.07 ) . Conclusions : Single-fraction stereotactic RT is feasible for selected patients with lung tumors . For those with prior thoracic RT , 25 Gy may be too toxic . Higher dose was associated with improved local control . Longer follow-up is necessary to determine the treatment efficacy and toxicity 
    Output:
    
CONCLUSION There was insufficient evidence to recommend a consensus view for optimal tumor parameters , dose fractionation , and technical delivery of treatment .