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e12566 Background: Oncotype Dx recurrence score (RS), is a prognostic and predictive test utilized for decision making in adjuvant therapy of 0-3 node/hormone receptor positive(HR+)/ HER-2-negative early breast cancer. Ki-67 is a marker of proliferating cells and is associated with prognosis and response. Immunohistological (IHC) assessment of Ki 67 expression is less expensive and with the approval of CDK inhibitors in the high risk adjuvant setting, it is increasingly being utilized in clinical decision making. A moderate to strong correlation between Ki67 and Oncotype Dx RS has been reported in the literature. We sought to examine the relationship of Ki 67 to Oncotype Dx RS in a community-based cancer center in rural central Nebraska. Methods: Forty-three consecutive postmenopausal breast cancer patients(pts) diagnosed and treated at our community based cancer center between 2020-2021 with T1–2 N0-1 M0, HR+, HER-2-negative disease were evaluated for histological type, tumor size, Nottingham grade, HR levels, Ki 67 expression (low < 10%, intermediate 10 ≥ Ki67 < 25 high ≥ 25), and Oncotype Dx RS(low <16,intermediate 16⩽RS<26), high ⩾26). Ki 67 and Oncotype Dx RS were treated as continuous variables to calculate a Pearson correlation coefficient. Results: Mean age at diagnosis was 59.4 years (range 48-89). Mean tumor diameter was 15.6 mm. 78.9% were intermediate histologic grade and 9.7% patients had lymph node involvement. Median expression of ER and PR were 90% (5-100) and 70% (0-100), respectively. The mean Ki 67 value was 17.5 (range 5-60 %), and mean Oncotype RS was 14.4 (range 4-34). There was a positive linear correlation between Ki 67 expression and Oncotype Dx RS (Pearson Correlation Coefficient=0.49, P-value <0.001). The vast majority of high Ki 67 pts (80%) had high/intermediate Oncotype RS. All pts with low Ki 67 (100%) had low/intermediate RS. Conclusions: Our community based rural cancer center data support a linear, statistically significant, positive correlation between Ki 67 and Oncotype Dx RS in early stage 0-3 node/HR+ positive breast cancer pts. Increasing use of Ki 67 testing in different clinical settings will generate more data to better define this correlation.[Table: see text]

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INTRODUCTIONCurrent trends in satellite communications point to the requirements for antenna systems that can radiate several shaped beams simultaneously, with each beam providing a different function such as telephony, TV, specialised business service etc. It is envisaged that such systems will employ electrically large diameter reflectors to achieve an adequate level of beam contouring and the isolation between the beams. The use of the conventional array-fed parabolic reflector antenna represents one possible approach to this requirement; however, the solution has the drawback of increased mass penalty and the feed system losses. It is evident that these limitations become particularly severe where each shaped beam is synthesised using narrow spot-beams from a large diameter focused reflector. In this context, the use of a shaped reflector rather than a focused reflector can offer potential benefits by reducing the number of feed elements that would be otherwise required. However careful attention must be given to the synthesis of the reflector surface shape which must be optimised for several beams simultaneously.In this paper we report on a study carried out for the European Space Agency to examine the application of shaped reflector antennas to such multicoverage scenarios. The design objective here is to derive two or more contoured beams from a single shaped offset reflector using either a single feed per beam or small array of feeds per beam as appropriate. The synthesis of such an antenna involves simultaneous optimisation of the reflector shape and the excitations of the feed array elements associated with each beam. In this context the geometrical optics based reflectors synthesis techniques are inappropriate and the design must be based on the more elaborate diffraction optimisation technique. SYNTHESIS APPROACHIn the approach adopted here, the reflector is initially described as a sum of two surfaces, viz a parboloid and a perturbation surface represented in terms of bi-cubic spline functions. The radiation field from this arbitary surface is then determined using a physical-optics surface current integration technique. The analysis is embedded in a search procedure (MINIMAX) which continuously monitors the radiation fields from the reflector as the design parameters are varied. In the case of the multi-element fed shaped reflector the design parameters include the coefficients of the bi-cubic spline functions and the excitations of the feed array elements. Where a group of feeds is assigned to a particular beam, only the contribution of that group of feeds is taken into account in calculating the coverage performance of the beam. DESIGN EXAMPLESThe above design approach has been used to deal with different multi-coverage scenarios including dual beam AFSAT coverage (C-band), the seven beam EUROPESAT coverage 1182 CHZ6642/89/000&1182 81.00 01989 IEEE (Ka-band) and the modified five beam EUROPESAT supercoverage. The results of the EUROPESAT coverage are presented below as an illustration. The coverag...