RESUMO
Objectives: Because size-based imaging criteria poorly capture biologic response in desmoid-type fibromatosis (DF), changes in MRI T2 signal intensity are frequently used as a response surrogate, but remain qualitative. We hypothesized that absolute quantification of DF T2 relaxation time derived from parametric T2 maps would be a feasible and effective imaging biomarker of disease activity. Methods: This IRB-approved retrospective study included 11 patients with DF, managed by observation or systemic therapy, assessed by 3T MRI. Tumor maximum diameter, volume, and T2-weighted signal intensity were derived from manual tumor segmentations. Tumor:muscle T2 signal ratios were recorded. Two readers measured tumor T2 relaxation times using a commercial T2 scanning sequence, manual ROI delineation and commercial calculation software enabling estimation of reader reliability. Objective response rates based on RECIST1.1 and best responses were compared between size-based and signal-based parameters. Results: Median patient age was 52.6 years; 8 subjects were female (73%). Nine patients with longitudinal assessments were followed for an average of 314 days. Median baseline tumor diameter was 7.2 cm (range 4.4 - 18.2 cm). Median baseline T2 was 65.1 ms (range 40.4 - 94.8 ms, n=11); median at last follow-up was 44.3 ms (-32% from baseline; range 29.3 - 94.7 ms, n=9). T2 relaxation times correlated with tumor:muscle T2 signal ratios, Spearman p=0.78 (p<0.001). T2 mapping showed high inter-reader reliability, ICC=0.84. The best response as a percentage change in T2 values was statistically significant (mean -17.9%, p=0.05, paired t-test) while change in diameter was not (mean -8.9%, p=0.12). Conclusions: Analysis of T2 relaxation time maps of DF may offer a feasible quantitative biomarker for assessing the extent of response to treatment. This approach may have high inter-reader reliability.
RESUMO
PURPOSE: We retrospectively compared the outcomes and costs of outpatient and inpatient management of low-risk outpatients who presented to an emergency department with febrile neutropenia (FN). PATIENTS AND METHODS: A single episode of FN was randomly chosen from each of 712 consecutive, low-risk solid tumor outpatients who had been treated prospectively on a clinical pathway (1997-2003). Their medical records were reviewed retrospectively for overall success (resolution of all signs and symptoms of infection without modification of antibiotics, major medical complications, or intensive care unit admission) and nine secondary outcomes. Outcomes were assessed by physician investigators who were blinded to management strategy. Outcomes and costs (payer's perspective) in 529 low-risk outpatients were compared with 123 low-risk patients who were psychosocially ineligible for outpatient management (no access to caregiver, telephone, or transportation; residence > 30 minutes from treating center; poor compliance with previous outpatient therapy) using univariate statistical tests. RESULTS: Overall success was 80% among low-risk outpatients and 79% among low-risk inpatients. Response to initial antibiotics was 81% among outpatients and 80% among inpatients (P = .94); 21% of those initially treated as outpatients subsequently required hospitalization. All patients ultimately responded to antibiotics; there were no deaths. Serious complications were rare (1%) and equally frequent between the groups. The mean cost of therapy among inpatients was double that of outpatients ($15,231 v $7,772; P < .001). CONCLUSION: Outpatient management of low-risk patients with FN is as safe and effective as inpatient management of low-risk patients and is significantly less costly.
