Heat can effect the partial denaturation of protein that is the basis of histological fixation. An objection to conventional forms of heating is that only small specimens can be used, as heat conduction is poor in biological materials.Microwave heating overcomes the limits imposed by poor heat conduction. Microwave energy is part of the electro-magnetic spectrum, of similar frequency to radar beam energy, and at a frequency of 2,450 megacycles per second penetrates several centimetres into biological material (Schwan, 1960).This energy is absorbed and converted into heat within the tissue. In effect microwave energy is an alternating electromagnetic field, the direction of which changes Fig. 1 The Microtron 200 power source connected by coaxial cable to the microwave chamber.
Various hazards of external cardiac massage, such as rib fracture and bone-marrow emboli, are well known. This paper describes a n unusual hazard, aortic aneurysm. T h e mechanism of production of this lesion differs in several respects from that of most closed-chest aortic lesions.
2794 Introduction Patients (pts) of older age, poor performance status (PS) and advanced stage with aggressive B cell lymphomas are regarded as poor prognosis and may receive no treatment, or palliative rather than curative chemotherapy. Studies suggest these pts may be undertreated and poor outcome may be partly related to undertreatment. Our unit has had a policy of offering treatment with curative intent to all pts presenting with aggressive B cell lymphomas, whatever their age or PS providing comorbidities allow. We reviewed the outcome of this policy. Methods All pts age≥70 years with diffuse large B cell lymphoma (DLBCL) or Burkitts lymphoma (BL) between 2000–2010 incl. were found from histology, chemotherapy and registry records. Poor PS pts were selected by including all who were inpatients during their 1st chemotherapy cycle, or if untreated, at diagnosis. If ECOG PS had not been prospectively recorded, ≥2 staff (from the 6 who were present throughout the 10 years) independently attributed status from memory and hospital notes. Only confirmed bedbound pts were designated PS4. Percentage chemotherapy doses delivered were calculated against the projected full dose and categorised into ≥85% Full, 60–85% RD, 30–60% HD. Pts receiving CHOP±R or CODOX-M/IVAC were called intensive (Int) and pts receiving low dose regimens called non-intensive (NI). Results 61 pts were found and 37 were inpatients. Of the 37 inpatients, 30 received chemotherapy, 29 for DLBCL and 1 for BL. Of the 30 treated pts (table 1) where parameters were assessable, LDH raised 92%, R-IPI ≥3 97%, PS 3/4 in 93%, stage3/4 86%, albumin <35g/l 70%. Of the 30 patients treated with chemotherapy, 18 achieved a CR with a median OS of 39 months(m) (range 8–123). There were 23 Int pts (9 were PS4, 7 of these being moribund), and 16 achieved CR median OS 48 m (range 12–99), 6 of them being PS4 and 4 were moribund. All pts achieving CR remained so except 1 late relapse (96m). Comorbidities were supported but did not influence treatment decisions except poor ejection fraction or dementia. (7 patients received no chemotherapy; declined ×3, cancer ×1, dementia ×1, not referred ×2) Discussion Our data show that very poor PS elderly pts can achieve CR (70%) with good OS with current intensive chemotherapy (CHOP±R, CODOX-M/IVAC±R). Further discussion refers to these pts (Int). CRs not only occurred in the PS2/3 pts, but also in 6/9 PS4 pts. The survivors could not be predicted and included 4 moribund pts. Toxicities were acceptable. Three of 4 moribund pts who survived received HD chemotherapy which was staggered due to emergency presentation. The 2nd cycle was given as soon as possible if improvement occurred (all responders did) with escalation of chemotherapy doses. This aggressive chemotherapeutic approach may have contributed to the good response rate. Our data show that putative toxicity is not a barrier to treatment with judicious dose reduction in the 1st cycle. Retrospective PS attribution was a weakness of the study. But objective parameters eg LDH, IPI, albumin and chemotherapy dose delivered concurred with the scores supporting their validity. PS4 criteria were objective. These data are important because they represent pts mostly excluded from trials. Recent data suggest that comorbidities may not influence survival. Our data support this. We suggest that elderly very poor PS pts can tolerate curative chemotherapy with encouraging remission rates and OS. Previous poor results may be due partly to undertreatment and most pts should be offered proper curative chemotherapy. A positive medical team attitude may be important. Disclosures: No relevant conflicts of interest to declare.
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