***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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    ***EXAMPLES*** 
    Input: Background and Purpose : The purpose of this sequential intervention study was to determine the rate of local recurrences and the rate of distant metastases in patients with invasive breast cancer who had been treated with breast-conserving surgery and postoperative radiation therapy to the whole breast either with postoperative electron boost in group 1 or with intraoperative electron boost ( IORT ) in group 2 . Patients and Methods : After breast-conserving surgery , 378 women with invasive breast cancer of tumor sizes T1 and T2 received 51–56.1 Gy of postoperative radiation therapy to the whole breast in 1.7-Gy fractions . 188 of those patients additionally received a postoperative electron boost of 12 Gy in group 1 from January 1996 to October 1998 . Consecutively , from October 1998 to March 2001 , 190 patients received intraoperative electron-boost radiotherapy of 9 Gy to the tumor bed in group 2 . The groups were comparable with regard to age , menopausal status , tumor size , grading , and nodal status . All statistical tests were twosided . Results : During a median follow-up period of 55.3 months in group 1 and 25.8 months in group 2 , local recurrences were observed in eight of 188 patients ( 4.3 % ) in group 1 , and no local recurrence was seen in group 2 ( p = 0.082 ) . Distant metastases occurred in 15 of the 188 patients ( 7.9 % ) in group 1 and in two of the 190 patients ( 1.1 % ) in group 2 ( p = 0.09 ) . The 4-year actuarial rates of local recurrence were 4.3 % ( 95 % confidence interval , 1.8–8.2 % ) and 0.0 % ( 95 % confidence interval , 0.0–1.9 % ) and the 4-year actuarial rates of distant metastases were 7.9 % ( 95 % confidence interval , 4.5–12.8 % ) and 1.1 % ( 95 % confidence interval , 0.1–3.8 % ) . Conclusion : Immediate IORT boost yielded excellent local control figures in this prospect i ve investigation and appears to be superior to conventional postoperative boost in a short-term follow-up . Hintergrund und Ziel : Ziel dieser sequentiellen Interventions studie war die Bestimmung der Lokalrezidiv- und Fernmetastasenrate von Patientinnen mit invasivem Mammakarzinom , die mit brusterhaltender Operation und anschließender Bestrahlung der gesamten Brust , aber verschiedenen Boostbestrahlungen therapiert worden waren . Gruppe 1 erhielt eine postoperative Boostbestrahlung und Gruppe 2 eine intraoperative Radiotherapie ( IORT ) in Boostmodalität . Patienten und Method ik : Nach brusterhaltender Operation erhielten 378 Patientinnen mit invasivem Mammakarzinom mit T1- und T2-Tumoren eine postoperative Bestrahlung der gesamten Brust von 51–56.1 Gy in 1.7-Gy-Fraktionen . Von Januar 1996 bis Oktober 1998 bekamen 188 Patientinnen in Gruppe 1  postoperativ zusätzlich eine Elektronenboostbestrahlung von 12 Gy . Von Oktober 1998 bis März 2001 erhielten 190 Patientinnen in Gruppe 2 eine intraoperative Elektronenboostbestrahlung von 9 Gy direkt auf das Tumorbett . Beide Gruppen waren bezüglich Alter , Menopausenstatus , Tumorgröße , Grading und Nodalstatus vergleichbar . Die statistische Analyse erfolgte zweiseitig . Ergebnisse : Nach einer mittleren Nachbeobachtungszeit von 55,3 Monaten in Gruppe 1 und 25,8 Monaten in Gruppe 2 traten bei acht der 188 Patientinnen in Gruppe 1 ( 4,3 % ) Lokalrezidive auf , während es in Gruppe 2 zu keinem Lokalrezidiv kam ( p = 0.082 ) . Fernmetastasen ereigneten sich bei 15 der 188 Patientinnen ( 7,9 % ) in Gruppe 1 und zwei der 190 Patientinnen ( 1,1 % ) in Gruppe 2 ( p = 0.09 ) . Die 4-Jahres-Raten für Lokalrezidive betrugen 4,3 % ( 95%-Konfidenzintervall 1,8–8,2 % ) und 0 % ( 95%- Konfidenzintervall 0–1,9 % ) und die 4-Jahres-Raten für Fernmetastasen 7,9 % ( 95%-Konfidenzintervall 4.5–12,8 % ) und 1,1 % ( 95%-Konfidenzintervall 0,1–3,8%).Schlussfolgerung : Die intraoperative Boostbestrahlung zeigt exzellente Ergebnisse bezüglich der Lokalrezidivrate und scheint der postoperativen Boostbestrahlung in der Kurzzeitnachbeobachtung überlegen zu sein The aim of this trial was to study the value of adding post-operative radiotherapy to lumpectomy in a subgroup of breast cancer patients with favourable patient- , tumour- , and treatment-related prognostic features . 152 women aged over 40 with unifocal breast cancer seen in preoperative mammography were r and omly assigned to  lumpectomy alone ( no-XRT group ) or to lumpectomy followed by radiotherapy to the ipsilateral breast ( 50 Gy given within 5 weeks , XRT group ) . All cancers were required to be invasive node-negative , smaller than 2 cm in diameter and well or moderately differentiated , to contain no extensive intraductal component , to be progesterone receptor-positive , DNA diploid , have S-phase fraction ≤7 and be excised with at least 1 cm margin . During a mean follow-up time of 6.7 years , 13 ( 18.1 % ) cancers recurred locally in the no-XRT and 6 ( 7.5 % ) in the XRT group ( P=0.03 ) . There was no difference between the groups in the ultimate breast preservation rate ( 95.0 % vs. 94.4 % in XRT and no-XRT , respectively , P=0.88 ) , distant metastasis-free survival ( P=0.36 ) , or 5-year cancer-specific survival ( 97.1 % in XRT and 98.6 in no-XRT ) . Radiation therapy given after lumpectomy reduces the frequency of ipsilateral breast recurrences even in women with small breast cancer with several favourable clinical and biological features . However , the breast preservation rate may not increase due to more frequent use of salvage mastectomies in patients treated with postoperative radiotherapy . © 2001 Cancer Research Campaign PURPOSE To evaluate perioperative morbidity , toxicity , and cosmetic outcome in patients treated with interstitial brachytherapy to the tumor bed as the sole irradiation modality after breast-conserving surgery . PATIENTS AND METHODS From November 1 , 2000 to January 31 , 2004 , 176 women with early-stage breast cancer became partakers in a protocol of tumor bed irradiation alone using pulsed-dose-rate ( PDR ) or high-dose-rate ( HDR ) interstitial multicatheter implants .  Patients became eligible , if their tumor was an infiltrating carcinoma < or = 3 cm in diameter , the surgical margins were clear by at least 2 mm , the axilla was surgically staged node-negative , the tumor was estrogen and /or progesterone receptor-positive , well or moderately differentiated ( G1/2 ) , the tumor did not contain an extensive intraductal component ( EIC ) and the patient 's age was > 35 years . Implants were positioned using a template guide , delivering either 49.8 Gy in 83 consecutive hours ( PDR ) or 32.0 Gy in two daily fractions over 4 days ( HDR ) . Perioperative morbidity , toxicity , and cosmetic outcome were assessed . Interim findings of the first 69 patients , who were treated in this multicenter trial , after a median follow-up of 24 months ( range , 15 - 39 months ) are presented . RESULTS One of the 69 patients ( 1.4 % ) developed a bacterial infection of the implant . No other perioperative complications , for example bleeding or hematoma , were observed . Acute toxicity was low : 2.9 % of the patients ( 2/69 ) experienced mild radiodermatitis . Late toxicity : hypersensation/mild pain 7.2 % ( 5/69 ) , intermittent but tolerable pain 1.4 % ( 1/69 ) , mild dyspigmentation 10.1 % ( 7/69 ) , mild fibrosis 11.6 % ( 8/69 ) , moderate fibrosis 1.4 % ( 1/69 ) , mild telangiectasia ( < 1 cm(2 ) ) 11.6 % ( 8/69 ) , and moderate teleangiectasia ( 1 - 4 cm(2 ) ) 1.4 % ( 1/69 ) . Good to excellent cosmetic results were observed in 92.4 % of the patients evaluated . All patients ( n = 176 ) remained disease-free to the date of evaluation . CONCLUSION This analysis indicates that accelerated partial breast irradiation with iridium-192 interstitial multicatheter PDR/HDR implants is feasible with low perioperative morbidity , low acute and mild late toxicity , and does not significantly affect cosmetic results at a median follow-up of 24 months AIM We believe that conservative treatment of early breast cancer may not require radiotherapy that encompasses the whole breast in all patients . We have developed a novel therapeutic approach that allows targeted intraoperative radiotherapy ( Targit ) to be safely and accurately delivered in a st and ard operating theatre . We are currently recruiting for a r and omized trial testing whether Targit can replace the whole 6 weeks of post-operative radiotherapy after breast conserving surgery . METHODS This paper describes the operative technique . It employs a miniature electron-beam-driven X-ray source called INTRABEAM ( PeC ) that emits soft X-rays ( 50 kV ) from within the breast . The X-rays are emitted from the tip of a 10 cm x 3.2 mm diameter probe , that is enclosed in a spherical applicator ( available in 2.5 - 5 cm diameter sizes ) , which in turn is inserted in the tumour bed and intraoperative radiotherapy is delivered in about 25 min . The prescribed dose is 5 and 20 Gy at 1 cm and 0.2 cm respectively , from the tumour bed . RESULTS The biologically effective dose is 7 - 53 Gy for alpha/beta=10 and 20 - 120 Gy for alpha/beta=1.5 . The quick attenuation of the radiation reduces the damage to normal tissues and allows radiotherapy to be delivered in a st and ard operating theatre . Tungsten impregnated rubber sheets , cut to size , are placed on the chest wall to protect the heart/lungs and over the wound to stop stray radiation . The skin dose is monitored with thermoluminescent detectors ( TLDs ) . After wide local excision of the tumour and good haemostasis , a spherical applicator is inserted in the tumour bed and the target breast tissues are wrapped around it with a purse-string suture . Thus , true conformation of the target around the applicator source is achieved in real time . CONCLUSION As a tumour bed boost , this technique has the potential to reduce local recurrence by avoiding geographical misses and achieving excellent dosimetry . In patients with low risk of local recurrence , it has the potential to replace the full 6 weeks of post-operative radiotherapy with considerable implication s to patients and hospitals BACKGROUND In women 70 years of age or older who have early breast cancer , it is unclear whether lumpectomy plus tamoxifen is as effective as lumpectomy followed by tamoxifen plus radiation therapy . METHODS Between July 1994 and February 1999 , we r and omly assigned 636 women who were 70 years of age or older and who had clinical stage I ( T1N0M0 according to the tumor-node-metastasis classification ) , estrogen-receptor-positive breast carcinoma treated by lumpectomy to receive tamoxifen plus radiation therapy ( 317 women ) or tamoxifen alone ( 319 women ) . Primary end points were the time to local or regional recurrence , the frequency of mastectomy for recurrence , breast-cancer-specific survival , the time to distant metastasis , and overall survival . RESULTS The only significant difference between the two groups was in the rate of local or regional recurrence at five years ( 1 percent in the group given tamoxifen plus irradiation and 4 percent in the group given tamoxifen alone , P<0.001 ) . There were no significant differences between the two groups with regard to the rates of mastectomy for local recurrence , distant metastases , or five-year rates of overall survival ( 87 percent in the group given tamoxifen plus irradiation and 86 percent in the tamoxifen group , P=0.94 ) . Assessment by physicians and patients of cosmetic results and adverse events uniformly rated tamoxifen plus irradiation inferior to tamoxifen alone . CONCLUSIONS Lumpectomy plus adjuvant therapy with tamoxifen alone is a realistic choice for the treatment of women 70 years of age or older who have early , estrogen- 
    Output:
    
Conclusion : Despite controversies regarding PBI after breast-conserving surgery , results of phase I – II trials suggest that sole tumor bed irradiation might be an appropriate therapeutic alternative for selected breast cancer patients .