***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: We evaluated the tolerance of a single dose of 800 - 1500 cGy , delivered with an electron beam from an IOERT-dedicated linear accelerator to the tumour bed in patients with breast cancer undergoing conservative treatment , instead of the traditional boost . We enrolled 27 patients ( cT1 - 2 , cN0 ) . The first 6 received a dose of 800 cGy , 6 1000 cGy , 10 1200 cGy and 5 1500 cGy .  External beam radiation therapy ( EBRT ) with a conventional schedule , 4000 cGy total dose , was performed after wound healing . The median gap between IOERT and EBRT was 8 weeks . Three patients with adverse prognostic factors undergoing chemotherapy , including doxorubicin or taxanes , received EBRT after completion of chemotherapy . One patient with a prosthesis implant had yielding of the surgical scar 8 months after IOERT ( after 4 cycles of doxorubicin and 4 cycles of CMF complicated by frequent mastitis ) . Another patient with a large serum collection in the axilla manifested delayed scar formation . In the others no significant increase in healing time or surgery-related morbidity was observed . Another 4 patients developed mastitis . The cosmetic outcome was good in 26/27 patients . This treatment is well tolerated at all IOERT doses delivered . In the follow-up , to date , there have been no local relapses We report the 10-year results of a r and omised clinical trial in which two different breast conservation treatment strategies were compared in women with small , non-metastatic primary breast cancer :  quadrantectomy , axillary dissection and radiotherapy ( QUART ) versus tumorectomy and axillary dissection followed by external radiotherapy and a boost with 192Ir implantation ( TART ) . No second surgery was given to women with affected surgical margins . Axillary node positive women received adjuvant medical therapy . From 1985 - 1987 , this trial accrued 705 patients , 360 in the QUART and 345 in the TART arm .  Crude cumulative incidence curves for intrabreast tumour recurrence ( IBTR ) and metastases as first events and mortality curves in each of the two treatment arms were computed . A crude cumulative incidence curve of IBTR as a second event ( in women who had already had a local recurrence ) was also computed . The two groups were compared in terms of hazard for IBTR , metastases or death occurrence by using Cox regression models , both with and without adjustment for patient age , tumour size , number of metastatic axillary nodes and histology . Possible interactions between the aforementioned prognostic factors and the type of surgery were also investigated . The two groups were well matched for baseline patient and tumour characteristics , the only exception being resection margins , which were more often positive in the TART group . At the Cox model , a significant difference between groups was detected for IBTR ( P < 0.0001 ) , but not for distant metastases and overall survival . In particular , 5- and 10-year estimates of crude cumulative incidence of IBTR were 4.7 and 7.4 % in the QUART group and 11.6 and 18.6 % in the TART group . The difference was not substantially affected by patient or disease characteristics . Likewise , the status of resection margins in women who underwent TART treatment did not significantly influence the risk of occurrence of IBTRs . Finally , the rate of second IBTR occurrence was relatively high , when compared with the rate of IBTR occurrence as first event . In summary , the results of this trial show that a better local control of the disease can be obtained with the more extensive surgical resection , i.e. QUART The Danish Breast Cancer Cooperative Group ( DBCG ) conducted a r and omized trial comparing breast conservation with mastectomy in patients with invasive mammary carcinoma . From January 1983 to March 1989 , the trial accrued a total of 1153 women . Of this number , 905 patients ( 79 % ) were r and omly assigned to one of the two treatment options , whereas 248 patients ( 21 % ) did not accept r and omization . Of the r and omly assigned patients , 90 % received the surgical option to which they had been originally assigned . In the breast conservation arm the tumor was excised with the intention of obtaining free margins determined at gross examination , and radiotherapy was subsequently administered to residual breast tissue . The axilla was dissected in all instances . Patient and tumor characteristics were similar in the two r and omization arms . The median follow-up time was 40 months . At 6 years of life-table analysis the probability of recurrence-free survival was 70 % in the breast conservation arm against 66 % in the mastectomy arm . Survival figures were 79 % against 82 % , respectively This report up date d previous findings , at the 15‐year mark , of the National Surgical Breast and Bowel Project ( NSAPB ) Protocol B‐06 with respect to the treatment of invasive breast carcinoma and the effects of pathologic features and the effects of some clinical features on its natural history OBJECTIVE This report describes the clinical evaluation of a novel stereotactic radiosurgical device for interstitial irradiation of malignant brain tumors . METHODS Fourteen patients with cerebral lesions less than 3.5 cm in greatest diameter were treated with a single fraction of stereotactic interstitial irradiation ( average , 12.5 Gy ) . Clinical evaluation , Karnofsky Performance Scale ratings , and neuroimaging studies were obtained at 6-week intervals postoperatively to assess treatment response . Reduction or stabilization of tumor size on follow-up imaging was accepted as local control , whereas tumor enlargement indicated local failure . INSTRUMENTATION This battery-powered miniature x-ray generator device produces low-energy x-ray photons that are attenuated rapidly within tissue . A dose decline rate proportional to 1/r3 yields extremely sharp dose fall-off curves with minimal exposure to surrounding tissue . Dose rates of 200 cGy per minute are possible , allowing for the administration of 12.5 Gy to a lesion 3 cm in diameter in less than 1 hour . RESULTS Local control ( stabilization or reduction in lesion size ) was obtained in 10 of the 13 patients with tumors with follow-up of 1.5 to 36 months ( mean , 12 mo ) . Of three patients with radiographic progression , recurrence was symptomatic in only one . All patients tolerated the procedure well , and most patients were discharged home the day after treatment . No new neurological deficits were noted after biopsy and irradiation . CONCLUSIONS Preliminary experience with this novel radiosurgical device has demonstrated its feasibility and safety . Clinical efficacy of this technique is now under investigation in an international multicenter study Local recurrences after breast conserving surgery occur mostly in the quadrant harbouring the primary carcinoma . The main objective of postoperative radiotherapy should be the sterilisation of residual cancer cells in the operative area , while irradiation of the whole breast may be avoided . We have developed a new technique of intra-operative radiotherapy ( IORT ) of a breast quadrant after the removal of the primary carcinoma . A mobile linear accelerator ( linac ) with a robotic arm is utilised delivering electron beams able to produce energies from 3 to 9 MeV. Through a perspex applicator , the radiation is delivered directly to the mammary gl and and to spare the skin from the radiation , the skin margins are stretched out of the radiation field . To protect the thoracic wall , an aluminium-lead disc is placed between the gl and and the pectoralis muscle . Different dose levels were tested from 10 to 21 Gy without important side-effects . We estimated that a single fraction of 21 Gy is equivalent to 60 Gy delivered in 30 fractions at 2 Gy/fraction . Seventeen patients received a dose of IORT of 10 to 15 Gy as an anticipated boost to external radiotherapy , while 86 patients received a dose of 17 - 19 - 21 Gy intra-operatively as their whole treatment . The follow-up time of the 101 patients varied from 1 to 17 months ( mean follow-up time was 8 months ) . The IORT treatment was very well accepted by all of our patients , either due to the rapidity of the radiation course in cases where IORT was given as the whole treatment or to the shortening of the subsequent external radiotherapy in cases where IORT was given as an anticipated boost . We believe that single dose IORT after breast resection for small mammary carcinomas may be an excellent alternative to the traditional postoperative radiotherapy . However , a longer follow-up is needed for a better evaluation of the possible late side-effects In a prospect i ve r and omized clinical trial conducted by the European Organization for Research and Treatment of Cancer ( EORTC ) , mastectomy was compared with breast-conserving therapy in 903 stage I and stage II breast cancer patients entering the study between 1980 and 1986 . The main participating centers were : Guy 's Hospital , London ; The Netherl and s Cancer Institute , Amsterdam ; University Hospital , Leuven ; Radiotherapy Institute , Rotterdam ; Breast Unit , Tijgerberg , S.A. The data were collected in the EORTC Data Center , Brussels . Treatment in the study arm consisted of lumpectomy , axillary clearance , and radiotherapy to the breast ( 50 Gy external irradiation in 5 weeks followed by boost with iridium implant of 25 Gy ) . Important in this study is the large number of TNM stage II patients ( 755 ) . Most patients were stage II because of the size of the tumor ( 2 - 5 cm ) . The patient and tumor characteristics in the study and control groups were well balanced . So far the survival curves and local recurrence rates are not statistically different for the two study arms . Tumor size was found in univariate analysis to be a significant risk factor for local recurrence in the breast-conserving therapy group but not in the mastectomy group . Results of salvage treatment for local recurrence were not better for the breast-conserving therapy group compared with the mastectomy group . Measurements of quality of life and cosmesis show a clear benefit for the breast-conserving therapy group BACKGROUND Radiotherapy prevents local recurrence of breast cancer after breast-conserving surgery . We evaluated the effect of a supplementary dose of radiation to the tumor bed on the rates of local recurrence among patients who received radiotherapy after breast-conserving surgery for early breast cancer . METHODS After lumpectomy and axillary dissection , patients with stage I or II breast cancer received 50 Gy of radiation to the whole breast in 2-Gy fractions over a five-week period . Patients with a microscopically complete excision were r and omly assigned to receive either no further local treatment ( 2657 patients ) or an additional localized dose of 16 Gy , usually given in eight fractions by means of an external electron beam ( 2661 patients ) . RESULTS During a median follow-up period of 5.1 years , local recurrences were observed in 182 of the 2657 patients in the st and ard-treatment group and 109 of the 2661 patients in the additional-radiation group . The five-year actuarial rates of local recurrence were 7.3 percent ( 95 percent confidence interval , 6.8 to 7.6 percent ) and 4.3 percent ( 95 percent confidence interval , 3.8 to 4.7 percent ) , respectively ( P<0.001 ) , yielding a hazard ratio for local recurrence of 0.59 ( 99 percent confidence interval , 0.43 to 0.81 ) associated with an additional dose . Patients 40 years old or younger benefited most ; at five years , their rate of local recurrence was 19.5 percent with st and ard treatment and 10.2 percent with additional radiation ( hazard ratio , 0.46 [ 99 percent confidence interval , 0.23 to 0.89 ] ; P=0.002 ) . At five years in the age group 41 to 50 years old , no differences were found in rates of metastasis or overall survival ( which were 87 and 91 percent , respectively ) . CONCLUSIONS In patients with early breast cancer who undergo breast-conserving surgery and receive 50 Gy of radiation to the whole breast , an additional dose of 16 Gy of radiation to the tumor bed reduces the risk of local recurrence , especially in patients younger than 50 years of age PURPOSE To define the role of a 10-Gy boost to the primary tumor in the conservative treatment of early infiltrating breast carcinoma treated by limited surgery and radiotherapy . PATIENTS AND METHODS Between 1986 and 1992 , 1,024 women with early breast carcinoma ( < or = 3 cm in diameter ) were treated by local excision , axillary dissection , and conventional 50-Gy irradiation given in 20 fractions over 5 weeks and then r and omly assigned to receive either no further treatment or a boost of 10 Gy by electrons to the tumor bed . The median follow-up time was 3.3 years as of September 1994 . The occurrence of telangiectasia was reported , and the patients were asked to evaluate the cosmetic result . RESULTS At 5 years , 10 patients of 521 who had received the boost ( Kaplan-Meier estimate of local relapse rate , 3.6 % ) and 20 of 503 who had received no further treatment ( Kaplan-Meier estimate of local relapse rate , 4.5 % ) had developed a local recurrence ( P = .044 ) . After adjustment for the main prognostic variables , the relative risk was still significantly lower for the boost group ( 0.3 ; range , 0.12 to 0.95 ) . The boost group had a higher rate of grade 1 and 
    Output:
    
Short-term results were similar for both treatment modalities in terms of local recurrence , disease-free and overall survival .