Keles et al. objectively quantified residual postoperative tumor volumes based on MRI, and showed that the volume of residual disease correlated with both time to progression and overall survival [20] (Fig. 10.4). The increasingly frequent demonstration of a significant impact for surgical resection in more recent studies may reflect the routine use of MR or CT imaging post-operatively to objectively quantify residual tumor. The determination of surgical impact on outcome is informative when a study accounts for established prognostic factors and objectively analyzes residual disease rather than percentage of resection or other subjective measures of resection not based on rigorous imaging data [21].

Two subgroups of HGG patients deserve additional mention: the elderly and non-GBM patients. The role of radical surgery for the elderly is controversial. While aggressive treatment strategies have been employed for the elderly (>65 or 70 years of age) and have been shown to provide meaningful periods of survival, the impact of surgical resection has not been adequately analyzed as an independent variable to more definitively define its impact on outcome. Evaluating the impact of surgical resection for grade III lesions is even more problematical than for grade IV lesions because they are more responsive to conventional therapy, display greater biological, clinical and radiological heterogeneity (e.g. less often contrast enhance), are less common than grade IV tumors, and the analysis of their extent of resection is often embedded in generic studies of HGGs. Not surprisingly, studies evaluating the efficacy of resection for grade III HGGs have reported conflicting outcomes.

It is virtually inevitable that HGGs recur or, more correctly, progress. The role of re-operation at the time of recurrence and its impact on outcome have been evaluated in several studies that demonstrate, at best, modest impact on overall survival and, in some cases, prolonged good quality of life compared with patients treated without re-operation [14, 22]. In a recent large study of re-operation in patients enrolled in clinical trials, surgical patients had a median survival of 36 weeks compared with 23 weeks for non-operated patients [22], but the difference was partially attributed to selection bias. Other studies have shown no association between extent of resection and survival at recurrence, with median survival of 33 weeks for GBM patients and 79 weeks for AA patients [14].

If the utility of surgical resection is based primarily on cytoreduction, then it would be important to know what proportion of the tumor burden is represented by the enhancing portion of a tumor versus the diffusely infiltra-tive component. Accurate assessment of total tumor burden is not possible with current imaging techniques, and problematic even with detailed examination of pathological material.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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