Total Failure Rate Research Articles

Development of Metal/Metal Hip Resurfacing

This author's development of metal/metal hip resurfacing began in 1989, with the first patient implantation in February 1991. In the first three years a pilot study identified optimum fixation as hydroxyapatite coated uncemented cups and cemented femoral components. From March 1994 hybrid fixed components have been used. These implants have generally been satisfactory with respect to fixation but high wear of the bearing, metallosis and osteolysis have been seen with some components inserted during 1996, a period during which the metal microstructure was altered by the heat processes, hot isostatic pressing and solution heat treatment. The Birmingham Hip Resurfacing was developed taking account of experience with earlier resurfacing designs. This implant employs hybrid fixation with a porous ingrowth acetabular component and has an as-cast metal microstructure having had no post casting heat treatments. During the past 4 years the author has performed over 1,000 Birmingham Hip Resurfacingís with a total failure rate of less than 1.0%.

Development of Metal/Metal Hip Resurfacing

This author's development of metal/metal hip resurfacing began in 1989, with the first patient implantation in February 1991. In the first three years a pilot study identified optimum fixation as hydroxyapatite coated uncemented cups and cemented femoral components. From March 1994 hybrid fixed components have been used. These implants have generally been satisfactory with respect to fixation but high wear of the bearing, metallosis and osteolysis have been seen with some components inserted during 1996, a period during which the metal microstructure was altered by the heat processes, hot isostatic pressing and solution heat treatment. The Birmingham Hip Resurfacing was developed taking account of experience with earlier resurfacing designs. This implant employs hybrid fixation with a porous ingrowth acetabular component and has an as-cast metal microstructure having had no post casting heat treatments. During the past 4 years the author has performed over 1,000 Birmingham Hip Resurfacingís with a total failure rate of less than 1.0%.

Real-time Transactions Need Their Constituting Tasks

ABSTRACT Transaction handling in real-time applications has been studied since quite a number of years, pursuing a variety of research topics. Considering concurrency control, in particular for replicated objects, the algorithms suggested have been moderate modifications of algorithms originally defined for non-real-time database applications. This resulted, for some of them (O2PL and OCC), in a considerable performance improvement (total deadline failure rate) compared to the original versions. As their specific time-sensitive parameter these real-time versions were designed to work on a transaction deadline. While transaction deadlines are to be chosen in accordance with the deadlines of the tasks constituting the transactions no attention has been paid to the latter ones. Taking the perspective of object or task/transaction similarity we experimentally demonstrate that it is highly advantageous (if not indispensable) for the real-time performance to fully utilize the task level and structure of transactions, in particular for safety-critical applications.

Alumina ceramic bearings for hip endoprostheses: the Austrian experiences.

The current authors review clinical and retrieval experiences with hemispheric monolithic alumina ceramic sockets (Group 1), implanted between 1976 and 1979, and similar modular titanium sockets with alumina ceramic inlays (Group 2), implanted between 1990 and 1995. Both cementless sockets articulated with alumina ceramic femoral ball heads for total hip joint replacements. Clinical followup of patients with hemispheric monolithic alumina ceramic sockets (Group 1, 138 sockets) resulted in a total failure rate of 19.6% after 5 to 20 years. Radiologic analysis of eight stable sockets showed migration of 0.2 mm to 2.89 mm, but in four sockets at risk for late aseptic failure after an average followup of 12.5 years as much as 13.4 mm of migration was seen. Histologic evaluation revealed pseudosynovial membranes as thick as 1 mm with fine birefringent wear particles within mononuclear macrophages around two stable retrieved sockets. The membranes around four loose sockets were 6 to 10 mm thick and also heavily loaded with larger alumina wear particles. After 7 years followup clinical analysis of patients with modular titanium sockets with alumina ceramic inlays (Group 2, 30 sockets) resulted in four revisions, compared with one revision of 50 identical sockets (control group) with polyethylene instead of alumina ceramic inlays. Wear particle analyses in scanning electron microscopy showed significantly more particles (x 10(9) +/- standard deviation/g dry tissue) from the control group (4.26+/-6.38), compared with alumina ceramic bearings of Group 1 (0.70+/-0.79), and of Group 2 (1.62+/-2.13). The alumina particle sizes ranged between 0.13 and 78.38 microm. The mean annual linear wear of 38.8 microm was calculated for the bearings in Group 1, and of 26.94 microm for bearings in Group 2. These results support the good tribologic and biologic performance of alumina ceramic bearings for total hip arthroplasty.

Combined bone grafting and delayed closure of the hard palate in patients with unilateral cleft lip and palate: facilitation of lateral incisor eruption and evaluation of indicators for timing of the procedure.

To compare outcomes of bone grafting performed before eruption of the lateral incisor to outcomes of grafting performed before eruption of the canine and to evaluate the long-term results of bone grafting combined with delayed closure of the hard palate during mixed dentition. Seventy consecutive patients (52 men and 18 women) with complete unilateral cleft lip and palate were studied. All patients underwent bone grafting with simultaneous closure of the cleft in the hard palate at the stage of mixed dentition. The velum had been repaired in infancy. Mean age for the bone grafting procedure was 8.4 years. Bone grafting was performed to facilitate eruption of the lateral incisor in 43 (61%) of the patients and to facilitate eruption of the canine in the remaining 27 (39%) patients. Intraoral radiographs were used to evaluate the morphologic characteristics of the cleft and the stage of eruption of the permanent lateral incisor and canine before bone grafting. Mean follow-up time was 4.0 years (range, 1-10.1 years). The mean time for the surgery, which included bone grafting and repair of the residual cleft in the hard palate, was 109 minutes, and the mean amount of bleeding was 121 ml. The rate of dehiscence in the flap covering the alveolar bone graft was 14%, and the rate of total failure of bone grafting was 3%. An oronasal fistula developed in the hard palate of 13% of patients, but the fistula was of sufficient size to serve as an indication for reoperation in only 6%. The postoperative alveolar bony height in the cleft area was more than 75% of the normal height in 94% of patients. Closure of the cleft space in the dental arch was performed or planned to be achieved orthodontically in 91% of patients. When bone grafting was performed to facilitate eruption of the lateral incisor, the cleft space was closed orthodontically in 100% of patients. The optimal indicator for timing of the bone grafting procedure from an orthodontic point of view was when the permanent lateral incisor or the canine close to the cleft was covered by a thin shell of bone (i.e., 7-9 years of age).

Results of cemented metal-backed acetabular components: A 10-year-average follow-up study

The clinical and radiographic results of 86 primary total hip arthroplasties performed in 74 patients from 1983 to 1987 with a cemented metal-backed acetabular component and a cemented collared straight femoral stem with a 32-mm head were reviewed at a mean follow-up of 10.1 years. Seven patients (9.2%) underwent acetabular component revision at a mean of 9.0 years after implantation; an additional 24 components (31.6%) demonstrated evidence of radiographic loosening, resulting in a total failure rate of 40.8%. Periacetabular radiolucencies were noted in Charnley zones at the following rates: 34.2% in zone I, 18.4% in zone II, and 27.6% in zone III. In addition, 18.4% and 38.2% of implants demonstrated evidence of migration and excessive polyethylene wear. Excessively vertical cup placement (>49° inclination) at the time of initial arthroplasty was statistically correlated with polyethylene wear, implant migration, and fixation failure. A trend of increasing implant failure was also noted with decreasing polyethylene liner thickness. Periacetabular cement mantle thickness was not statistically correlated with subsequent component loosening or failure. Results of Kaplan-Meier survivorship analysis using revision as an endpoint showed 93.6% survivorship at 10 years and 88.4% at 12 years. The mean modified Harris hip scores were 46.9 preoperatively and 81.8 at final follow-up. The significant overall rates of radiographic loosening, migration, polyethylene wear, and implant revision confirm the suspected trend of increasing failure rates of cemented metal-backed acetabular components over time.

Enhanced 3D-Databases: A Fully Electrostatic Database of AM1-Optimized Structures

In a feasibility study, a single conformation 3D version of the Maybridge database (53 471 compounds) has been produced using geometries optimized with AM1 semiempirical MO-theory. The database entries include full electrostatic information within the NAO-PC model and can be used to generate spectroscopic and physical properties using established QSPR models. The data were generated from the original database using custom cleanup software to remove database inconsistencies and, for instance, to isolate the “interesting” ion of ion pairs, 2D to 3D conversion using CORINA and subsequent geometry optimization using VAMP. The complete geometry optimization run was carried out in less than 15 h elapsed time on a Silicon Graphics Origin 2000 with 126 processors. The total failure rate for the structure cleanup, 2D to 3D conversion, and geometry optimization steps was around 1%.

Multiobjective optimal placement of convectively cooled electronic components on printed wiring boards

This paper presents a solution methodology for multiobjective optimization problems in the context of models for the placement of components on printed wiring boards (PWB's). The methodology combines the use of a flow and heat transfer solver, a genetic algorithm for the adaptive search of optimal or near-optimal solutions, and a multiobjective optimization strategy [Pareto optimization or multiattribute utility analysis (MUA)]. Using as the optimization criterion, the minimization of an estimate of the failure rate of the system of components due to thermal overheating (via an Arrhenius relation), the effectiveness of the present solution methodology is demonstrated by reference to a case with known optimal solutions. The results obtained using the same solution methodology for a multiobjective optimization problem (a variation of the case study) involving the minimization of the aforementioned total failure rate of the system as well as the minimization of the total wiring length (given some interconnectivity requirements) are presented and discussed for both Pareto optimization and MUA.

Surgical Technigues And Results İn Cholesteatoma Surgery

§/ A review of 349 patients with cholesteatoma operated between 1980 and 1995 was done. Of 349 patients, 272 cases had documented follow-up for 1 year or longer and were included in the study which consists of the incidence of residual and recurrent cholesteatoma. The most appropriate surgical technique was performed for each individual case. The surgical techniques were placed in two groups. Open cavity technique: 120 radical mastoidectomy, 26 modified radical mastoidectomy; closed technique: 113 intact canal wall tympanoplasty with mastoidectomy, 13 planned two stage procedure. Recurrence rates were 7.5% with open technique and 11.1% with closed technique. Residive rates were 9.6% with open technique and 5.5% with closed technique. Total failure rate was 17% with open technique and 16.6% with closed technique. The mean follow-up period was 30 months. In our series, there was no significant difference in the incidence and total failure rate of recurrent and residual cholesteatoma between open cavity and closed cavity techniques (p> 0.05). Cerrahi Teknikler ve Sonuclarimiz 1980-1995 yillari arasinda kolesteatoma tanisiyla opere edilen 349 hasta incelendi. 349 hastadan 272'si bir yildan fazla takip edilmisti. Bu hastalar calismaya alinarak rezidiv ve rekurrens yonunden degerlendirildi. Her hasta icin en uygun cerrahi yontem secildi. Cerrahi teknikler iki gruba ayrildi. Acik teknik: 120 radikal mastoidektomi, 20 modifiye radikal mastoidektomi; kapali teknik, 113 in takt kanal wall timpanoplasti ve mastoidektomi, 13 iki asamali timpanoplasti idi. Rekurrens oranlan acik teknik icin %7.5 ve kapali teknik icin % 11.1 olarak bulundu. Rezidiv oranlari acik teknik icin %9.6 ve kapali teknik icin %5.5 bulundu. Toplam basarisizlik orani acik teknik icin %17, kapali teknik icin %16.6 bulundu. Ortalama takip suresi 30 ay idi. Bu seride iki grup arasinda rekurrens ve rezidiv yonunden anlamli fark bulunamamistir.

Treatment policy after poor fertilization in the first IVF cycle.

The chance of recurrence of poor fertilization in a second in vitro fertilization (IVF) cycle was assessed. Total fertilization failure was defined, and the relationship between the fertilization rate and the number of motile sperm cells per milliliter of semen was assessed. Patients with a total fertilization failure or poor fertilization (20% or less of the oocytes fertilized) were divided into three subgroups with different chances of fertilization and were followed in a subsequent IVF cycle. The recurrence rate of total fertilization failure was high in all three groups (45-70%), and poor fertilization frequently occurred in the second cycle (50-75%). Poor fertilization frequently recurs in the second IVF cycle. The use of intracytoplasmic sperm injection could be considered after fertilization of 20% or less of oocytes in the first cycle, irrespective of the number of motile sperm cells per milliliter of semen.

Extracardiac Fontan operation for complex cardiac anomalies: Seven years' experience

Methods: Between 1988 and 1995, 60 patients with complex cardiac anomalies underwent a total extracardiac cavopulmonary connection, a combination of a bidirectional cavopulmonary anastomosis with an extracardiac conduit interposition between the inferior vena cava and pulmonary arteries, except in one patient in whom direct anastomosis was possible. In 40 patients the total extracardiac cavopulmonary connection followed preliminary bidirectional cavopulmonary anastomosis, associated with a modified Damus-Kaye-Stansel anastomosis in 16. The conduits were constructed of Dacron fabric ( n = 34), homografts ( n = 3), and polytetrafluoroethylene ( n = 22). Results: Total early failure rate was 15% ( n = 9). Six patients died, and three more had conduit takedown owing to pulmonary artery stenosis and hypoplasia ( n = 2) and severe atrioventricular valve regurgitation ( n = 1). Two other patients required anastomosis revision owing to stricture. In a mean follow-up of 48 months (6 to 86 monthe) there were no late deaths (actuarial 5-year survival 88% ± 4%); 52 of 54 patients are in New York Heart Association class I or II. Two patients required pulmonary artery balloon dilation or stent implantation, or both, after total extracardiac cavopulmonary connection. Late tachyarrhythmias were detected in four of 54 patients: two had sick sinus syndrome with flutter necessitating a pacemaker implantation and two had recurrent flutter (actuarial 5-year arrhythmia-free rate 92% ± 4%). Conduit patency was evaluated by serial magnetic resonance imaging studies. Preliminary data showed a 17.8% ± 7.6% mean reduction in conduit internal diameter during the first 6 months after total extracardiac cavopulmonary connection, with no progression over the next 5 years. Conclusion: These results demonstrate that the total extracardiac cavopulmonary connection provides good early and midterm results and may reduce the prevalence of late arrhythmias in patients undergoing the Fontan operation. (J Thorac Cardiovasc Surg 1997;114:1020-31)

Outcome of the pelvic pouch procedure in patients with prior perianal disease

There is concern that patients with presumed ulcerative colitis and significant perianal disease may in fact have Crohn's disease. Moreover, prior perianal disease may be an independent factor for poor outcome of the pelvic pouch. The aim of this study was to evaluate the effect of prior perianal disease on pelvic pouch outcome. Between 1982 and 1994, 52 of 753 patients (6.9 percent) who had a pelvic pouch procedure were prospectively identified as having perianal disease. Outcome of the pelvic pouch of these 52 patients (Group I) were compared with the outcome of 701 pelvic pouch patients with no prior perianal disease (Group II). The perianal diseases identified in Group I were fissure-in-ano (17), perianal abscesses (13), fistula-in-ano (7), rectovaginal fistula (3), and significant hemorrhoids/skin tags (25). Eleven patients (21 percent) had more than one type of perianal disease. Twenty-seven patients (52 percent) required a total of 33 perianal operations for the different anal pathologies. Both groups were comparable for the following characteristics: age at time of pelvic pouch procedure, pathology (ulcerative colitis or indeterminate colitis), design of pouch, and type of ileoanal anastomosis (handsewn or stapled). An ileoanal anastomosis leak developed in 21 percent of patients (n = 11) in Group I vs. 11.4 percent (n = 80) in Group II (P < 0.05). Perianal postoperative complications occurred in 11.5 percent of patients (n = 6) in Group I vs. 1.7 percent (n = 12) in Group II (P < 0.05). Total pouch failure rate was not significantly different between the two groups (11.5 vs. 7.6 percent; P > 0.05). Crohn's disease was subsequently diagnosed in 1.9 vs. 2.7 percent (P > 0.05). Subgroup analysis of Group I patients showed no significant difference in outcome according to type of perianal lesion or a history of perianal surgery. Prior perianal disease significantly increases the risk of developing an ileoanal anastomotic leak and postoperative perianal complications. However, a pelvic pouch procedure may be an acceptable surgical alternative for selected ulcerative colitis patients with prior perianal disease because the overall pouch failure rate is not significantly increased.

Effects of motion, ambient light, and hypoperfusion on pulse oximeter function

Study Objective: To compare the performance of five pulse oximeters during hypoperfusion, probe motion, and exposure to ambient light interference. Design: Prospective study. Setting: Laboratory facility at a university medical center. Patients: 8 unanesthetized, ASA physical status I volunteers. Interventions: We evaluated five common pulse oximeters with respect to three scenarios: (1) an operating room light was shone on oximeter probes, (2) a motion generator was used to generate 2 Hz and 4 Hz hand motion, and (3) a pneumatic compression device overlying the brachial artery was used to simulate hypoperfusion. Electrocardiographic (ECG) and arterial blood gas values were considered gold standards for heart rate (HR) and oxygen saturation (SpO 2) respectively. SpO 2 nondisplay and values greater than 4% from simultaneous arterial SaO 2-oximeter values were defined as errors. Nondisplay of HR, or HR greater than 5% from ECG values, were also considered errors. Measurements and Main Results: The Ohmeda and Nellcor N200 with finger probe had the highest total failure rates with respect to both SpO 2 and HR due to ambient light interference ( p < 0.05). The Nellcor N200 with finger probe and N200 with C lock were the most accurate with regard to SpO 2 during 2 Hz and 4 hz. motion ( p < 0.05). However, all oximeters failed dramatically during 4 Hz motion when measuring HR. In the hypoperfusion model, the Nellcor N200 with finger probe and the Nellcor C Lock oximeters performed significantly better than all others in terms of both HR and SpO 2 ( p < 0.05), while the Criticare oximeter failed 100% of the time. Conclusion: There are significant differences in the accuracy of commercially available pulse oximeters during nonideal circumstances, with failure rates varying from approximately 5% to 50% depending on the oximeter and source of interference. Furthermore, no single oximeter performed the best under all conditions.

The role of transradial diagnostic angiography.

To evaluate the use of 4 Fr radial artery catheters as an alternative to both transbrachial and transfemoral approaches. Seventy examinations were performed via the transradial route using 4 Fr 130-cm-long pigtail catheters. Prior to puncture the radial artery was assessed with pulse oximetry to ensure that it did not contribute the dominant blood supply to the hand. Patients were reassessed for complications within 24 hr of the procedure. Acceptable images were obtained in femoral arteriography, arch aortography, and selective carotid studies. In three of six renal arteriograms, images were suboptimal. There was a total technical failure rate of 5.7%. Significant complications were encountered in 4.3%, but no hand ischemia occurred. The transradial route for arteriography is easy to learn and has a low complication rate. It is a reasonable alternative approach to transfemoral arteriography for true outpatient peripheral angiography and in cases where the transfemoral route is not feasible, though it did not prove satisfactory for renal arteriography in hypertensive patients.

Radiotherapy for localized prostate carcinoma. The correlation of pretreatment prostate specific antigen and nadir prostate specific antigen with outcome as assessed by systematic biopsy and serum prostate specific antigen.

The objective of this study was to correlate the failure pattern of localized prostate carcinoma after radiotherapy (RT) with pretreatment (preTx) PSA and post-RT nadir PSA, using systematic biopsies and serum PSA in the assessment of outcome. From January 1990 to February 1994, 207 patients treated with external beam RT were followed prospectively with systematic transrectal ultrasound-guided biopsies and measurements of serum PSA levels. Three hundred forty-three biopsies were performed, with 4-7 samples taken per session. The distribution of T classification was as follows: 19 patients had T1b, 15 had T1c, 34 had T2a, 79 had T2b/c, 53 had T3, and 7 had T4. Median follow-up was 36 months (range, 12-70 months). Failures were categorized as biochemical (chemF) (PSA > 2.0 ng/mL and > 1 ng/ mL over nadir), local (LF) (positive biopsy and PSA > 2), and distant (DF). The Cox proportional hazards model was used for multivariate analysis (MVA). Overall, failures were seen in 68 of 207 patients: 20 LF, 24 DF, 7 LF + DF, and 17 chemF. In univariate analysis, failures correlated significantly with preTx PSA, post-RT nadir PSA, T classification, and Gleason's score (GS). The total failure rate was 12% for T1b, T1c, and T2a; 39% for T2b and T2c; and 60% for T3 and T4 (P < 0.0001). By evaluation with preTx PSA, at 36 months the total failure rate was 3% for preTx PSA < or = 5 ng/mL 16% for 5.1-10 ng/mL, 32% for 10.1-15 ng/mL, 42% for 15.1-20 ng/mL, 63% for 20.1-50 ng/mL, and 88% for > 50 ng/mL (P < 0.0001). By evaluation with post-RT nadir PSA, at 36 months the total failure rate was 4% for nadir PSA < or = 0.5 ng/ mL, 26% for 0.6-1 ng/mL, 33% for 1.1-2 ng/mL, and 92% for > 2 ng/mL (P < 0.0001). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0005) were independent predictors for any failure. LF occurred in 13% of patients (27 of 207). For these 27 patients, the categorization of T classification was: T1b/T1c/T2a, 7%; T2b/T2c, 16%; and T3/T4, 15% (P = not significant). In MVA, only nadir PSA (P = 0.0004) predicted for LF. DF occurred in 15% of patients (31 of 207). In MVA, nadir PSA (P < 0.0001) and T classification (P < 0.0001) predicted for DF, with pretreatment PSA of borderline significance (P < 0.05). To assess preTx predictors of outcome, post-RT nadir PSA was removed from the model. PreTx PSA then became the dominant variable to predict any failure (P < 0.0001), LF (P = 0.05), chemF (P = 0.0001), and DF (P < 0.003), while T classification also predicted for any failure (P = 0.03), chemF (P = 0.05), and DF (P < 0.0001). Systematic prostate biopsies, performed as part of the rigorous followup of prostate carcinoma after RT, define the patterns of failure and confirm the prognostic value of preTx PSA, post-RT nadir PSA, and T classification. Prior to treatment, preTx PSA is the overwhelming independent predictor of failure, but it is surpassed by post-RT nadir PSA when this is added to the model.

The temporalis muscle flap revisited on its centennial: advantages, newer uses, and disadvantages.

Analysis of a series of 85 temporalis muscle flaps performed in 81 patients is presented. The flaps were used in a wide range of locations ranging from intracranial to mandible and for a large variety of diagnostic categories. A detailed examination of the indications and use of the muscle for cranial base and palatal defects is provided. The amount of muscle used varied considerably from 10 to 90 percent. Complications associated with the use of the temporal muscle included a 2.4 percent total flap failure rate and a 9.4 percent minor complication rate. When greater than half the muscle was used, temporal hollowing, the principal donor defect, was imperceptible (39 percent) or mild (46 percent) in a majority of patients and severe in only a few (16 percent). Recommendations for prevention and treatment of this contour deformity are discussed in depth.

Acetabular revision using a bone-ingrowth total hip component in patients who have acetabular bone stock deficiency

The clinical and radiologic results of acetabular revision using a porous titanium-mesh metal-backed acetabular component fixed to the pelvis with screws were studied in 30 consecutive patients (32 hips) who had moderate or severe acetabular bone loss. All of the acetabula were classified as type III or IV according to the American Association of Orthopaedic Surgeons' acetabular grading system. Particulate autologous or allogenic bone—graft was used in 75% of the reconstructions. The mean follow-up period was 69 months (range, 46–109 months). Three acetabular components (9%) were rerevised for aseptic loosening at an average of 64 months, including one patient who had a primary diagnosis of radiation necrosis of the ilium. The average Harris hip score for the remaining 29 hips rose from 46 to 81. The radiologic failure rate was 3% (1 of 29 unrevised hips) for a total failure rate of 12%. No pelvic osteolysis was seen with this implant. Revision of acetabula that have moderate or severe bone deficiency by a bone-ingrowth acetabular component fixed with screws and bone—graft appears to be successful in restoring bone stock and providing a stable, pain-free reconstruction.

Signal Extraction Technology

Signal Extraction Technology

Signal Extraction Technology

Signal Extraction Technology

Timing of radiotherapy and chemotherapy following breast-conserving surgery for patients with node-positive breast cancer

Purpose : A controversy exists regarding whether it is safe to delay radiation therapy until the completion of chemotherapy following breast-conserving surgery for patients with node-positive breast cancer. Within the context of two concurrent randomized clinical trials we had the opportunity to evaluate outcomes for patients who received breast irradiation after completing different durations of chemotherapy. Methods and Materials : From July 1986 to April 1993 the International Breast Cancer Study Group (IBCSG) Trial VI randomly assigned 1554 pre/perimenopausal node-positive breast cancer patients to receive cyclophosphamide, methotrexate, and 5-fluorouracil (CMF) for either three consecutive courses on months 1–3, or six consecutive courses on months 1–6, both with or without reintroduction CMF, IBCSG Trial VII randomly assigned 1266 postmenopausal node-positive breast cancer patients to receive tamoxifen for 5 years, or tamoxifen for 5 years with three cycles of CMF, both with or without three courses of delayed CMF. Both trials allowed a choice of mastectomy, or breast-conserving surgery plus radiation therapy, and both were stratified by type of surgery. Radiotherapy was delayed until the initial block of CMF was completed; 4 or 7 months after surgery for pre/perimenopausal patients, and 2 or 4 months after surgery for postmenopausal patients. Over both trials, 718 neglible patients elected to receive breast-conserving surgery plus radiation therapy: 433 on Trial VI, and 285 on Trial VII. Four-year actuarial total failure rates (failure at any site), risks of developing distant metastases (DM at any time during conservation), an overall survival (OS) were estimated using the Kaplan-Meier method. To avoid potential bias due to competing causes of failure, only patients who could be followed for at least 4 years (enrolled prior to July 1, 1990) were used to evaluate the patterns of first relapse site. Crude percents of local failure with or without other sites (LF), distant metastases including regional nodal failure (DM/RNF), or other first events (second primaries/death without recurrence) were estimated for each treatment group. For this report, an intent to treat analysis was performed at a median follow-up of 48 months. Results : No differences were found in the 4-year actuarial total failure rates, risks of developing distant metastases, and overall survival among the two radiotherapy groups of each study. The cumulative incidence of types of first failure and the 4-year crude rates showed no treatment differences in the patterns of site of first event. Estimates for the 4-year crude percent of local failures were 8 and 9% for pre/perimenopausal patients who had radiation therapy at 4 or 7 months after surgery, and 3 and 6% for postmenopausal patiens who had radiation therapy at 2 months or 4 months after surgery. Conclusions : For node positive patients receiving breast-conserving surgery followed by radiation therapy, the incidence of breast recurrence in the conserved ipsilateral breast within 4 years was between 8 and 9% for pre/perimenopausal patients and between 3 and 6% for postmenopausal patients. After 48 months of median follow-up, administering radiation therapy after three or six cycles of CMF for pre/perimenopausal women, or after no cycles or three cycles of CMF for postmenopausal women does not influence overall efficacy or local control in this series.