Early Detection and Quantitative Diagnostic Modalities                                                                                                                                                 
                                                                                                               
The earlier tha
Early Detectiont incipient or sub-clinical lymphedema is detected, the more likely that therapy can be instituted when it is most effective in maintaining relative normality. So one of the important goals of current research is to develop procedures and methods to help in the early detection of  changes in tissues that are predictive of subsequent overt lymphedema. In the case of potential breast cancer treatment related lymphedema (BCRL), one approach is to assess arms prior to surgery and then follow-up with repeated assessments at standard intervals ranging between 3-6 months. At present it is not clear which assessment (measurement) method is best for early detection. Detection of early changes in limb volume or girth, tissue water via bioimpedance or tissue dielctric constant, or tissue properties alone or combined may be useful. These methods and approaches have been and are currently being investigated. The quantitative criteria or threshold whereby a diagnostic decision can be made as to the presence of  'sub-clinical' lymphedema is not known with certainty for any method.
Using Limb Girth or Volume Changes
Quantitative criteria for 'clinically manifest' limb lymphedema is somewhat arbitrary, but for unilateral limb involvement certain criteria are in use. These include conditions in which the affected arm as compared to the other arm has a girth greater than 2 cm or a volume greater than 200 ml or 10% (Stanton et al.,2000). Because of differences between normal paired-arms (up to 4%), slight volume changes encountered early on,and other factors, the use of  such thresholds to detect sub-clincial lymphedema may not be  satisfactory (Stanton et al., 2006). If presurgery measurements are made, then changes in limb girth at one or more sites along the arm, or arm volume changes from baseline, may be useful to indicate probable lymphedema with varying degrees of specificty and sensitivity depending on criteria set (Bland et al., 1993). The choice of criteria also affects the reported incidence of BCRL (Armer et al., 2005). As an approach for early detection and early treatment, arm volumes were measured prior to surgery in 196 women and at 3 month intervals after surgery (
Stout Gergich et al.,2008). Using an increase in arm volume greater than 3% as criteria for lymphedema, they found that 43 (21.9%) exceeded the threshold by 6.9 months post-surgery. If these women then wore a compression garment for about 4 weeks, their increased arm volumes (83+/-119 ml)was reduced by 48+/-103 ml, which was sustained for 4.8+/-4.1 months of followup.