The aim of this study was to assess the incidence and risk factors of pelvic fractures as a result of radiation therapy in women with gynecological cancer. We retrospectively reviewed 3530 female patients treated at our institute between 1980 and 1998 with megavoltage radiation with or without brachytherapy for cancer in the pelvic area. Eligible were patients with vulvar, vaginal, cervical, endometrial, and fallopian tube cancer. Median follow-up was 88 months (range 0-240). Emphasis was put on treatment-related and patient-related risk factors. Of the eligible 3155 patients, 15 developed symptomatic bone fracture caused by osteoradionecrosis, which makes an overall incidence of 0.44% The diagnosis was based on anamnesis, clinical course, and X-ray or computed tomography images. Median time of onset was 44 months (range 6-197). All patients had pain as the first symptom. The only independent predictive factor for developing osteoradionecrosis seemed to be preexistent osteoporosis. Other risk factors that are related to osteoporosis include higher age, postmenopausal status, or steroid treatment. We did not find any significant treatment-related predictive factor for pelvic osteoradionecrosis. Patients with osteoporosis are probably at the highest risk for developing osteoradionecrotic fractures after pelvic radiotherapy. More studies are needed to find out other endogenous predictive factors.
A new measurement of ∆σ T for polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. A polarized neutron beam was obtained from the 3 H(d, n) 4 He reaction; proton polarization over 90% was achieved in a frozen spin target of 20 cm 3 volume. The measurement yielded the value ∆σ T = (−126 ± 21 ± 14) mb. The result of a simple phase shift analysis for the 3 S 1 − 3 D 1 mixing parameter ǫ 1 is presented and compared with the theoretical potential model predictions.
A new measurement of ∆σ L for longitudinally polarized neutrons transmitted through a polarized proton target at 16.2 MeV has been made. This complements our previous measurement of ∆σ T at the same energy and after a phaseshift analysis improves the precision of the previous value of 3 S 1 − 3 D 1 mixing parameter 1 . The measurement yields the value ∆σ L = (−55 ± 20 ± 7) mb. The result of a simple phase shift analysis for 1 is presented and compared with the theoretical potential model predictions and other experiments. 25.40.Dn; 24.70.+s; 13.75.Cs In the last decade a considerable progress has been achieved in studying low energy neutron-proton elastic scattering. Beside other problems attention has been paid to clarify the role of tensor force in NN interaction. This force is characterized by the 3 S 1 − 3 D 1 mixing parameter 1 which cannot be measured directly, so only measurements of spin observables sensitive to it can improve the 1 determination. Such observables are the spin-dependent total cross-section differences ∆σ T and ∆σ L , the spin correlation coefficient A 00nn (ϑ) at 90 deg c.m. angle and the spin transfer parameter K 0nn0 (ϑ). The A 00nn (ϑ) measurement at 90 deg c.m. is presented by Schöberl et al. for 13.7 MeV neutron energy (Erlangen 1988 [1]) and by Doll et al. for 19, 21 and 25 MeV (Karlsruhe 1989 [2]). The spin transfer parameter K 0nn0 (133 deg c.m.) was measured at 25.8 and 17.4 MeV by Ockenfels et al. (Bonn 1990 [3, 4]), while ∆σ T was measured in TUNL in the 3.65-11.60 MeV energy range (1993 [5]) and at 16.2 MeV in our laboratory (1993 [6]). Furthermore, ∆σ L has been measured at 66 MeV incident neutron energy at Villigen (1992 [7]). PACS:Analyses of the results show apparent discrepancies, namely around 15 MeV, where two older measurements from Erlangen and Bonn indicate the existence of a local minimum in contrary to potential model and PSA predictions, while our ∆σ T measurement supports the predicted behaviourof 1 .However, our value 1 = (1.46 ± 1.32) deg had a relatively large error, so we studied how to determine this mixing parameter more precisely to find a more definite answer to the 1 problem.As it became infeasible to improve the 1 precision via measuring ∆σ T , we performed a new measurement with longitudinally polarized beam and target to obtain ∆σ L and furthermore ∆σ T − ∆σ L , which is the quantity sensitive namely to 1 , as shown in [5].The measurement of ∆σ L has been performed using the classical transmission method, i.e. the relative difference in attenuation of a polarized neutron beam passing through a polarized proton target has been measured.The experimental setup was similar to the one used for the ∆σ T measurement described in [6], so only brief description with more stress to the modifications will be presented here.In the present experiment a frozen spin polarized proton target with a dilution refrigerator has been used. Propanediol C 3 H 8 O 2 with a paramagnetic Cr(V) impurity was used as a target material. Typical proton polarization obtained was 9...
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