Person:

Mathisen, Douglas

Purpose We investigated the metabolic response of lung cancer to radiotherapy or chemoradiotherapy by 18F-FDG PET and its utility in guiding timely supplementary therapy. Methods: Glucose metabolic rate (MRglc) was measured in primary lung cancers during the 3 weeks before, and 10–12 days (S2), 3 months (S3), 6 months (S4), and 12 months (S5) after radiotherapy or chemoradiotherapy. The association between the lowest residual MRglc representing the maximum metabolic response (MRglc-MMR) and tumor control probability (TCP) at 12 months was modeled using logistic regression. Results: We accrued 106 patients, of whom 61 completed the serial 18F-FDG PET scans. The median values of MRglc at S2, S3 and S4 determined using a simplified kinetic method (SKM) were, respectively, 0.05, 0.06 and 0.07 μmol/min/g for tumors with local control and 0.12, 0.16 and 0.19 μmol/min/g for tumors with local failure, and the maximum standard uptake values (SUVmax) were 1.16, 1.33 and 1.45 for tumors with local control and 2.74, 2.74 and 4.07 for tumors with local failure (p < 0.0001). MRglc-MMR was realized at S2 (MRglc-S2) and the values corresponding to TCP 95 %, 90 % and 50 % were 0.036, 0.050 and 0.134 μmol/min/g using the SKM and 0.70, 0.91 and 1.95 using SUVmax, respectively. Probability cut-off values were generated for a given level of MRglc-S2 based on its predicted TCP, sensitivity and specificity, and MRglc ≤0.071 μmol/min/g and SUVmax ≤1.45 were determined as the optimum cut-off values for predicted TCP 80 %, sensitivity 100 % and specificity 63 %. Conclusion: The cut-off values (MRglc ≤0.071 μmol/min/g using the SKM and SUVmax ≤1.45) need to be tested for their utility in identifying patients with a high risk of residual cancer after standard dose radiotherapy or chemoradiotherapy and in guiding a timely supplementary dose of radiation or other means of salvage therapy. Electronic supplementary material The online version of this article (doi:10.1007/s00259-013-2348-4) contains supplementary material, which is available to authorized users.

The primary treatment for end-stage lung disease is lung transplantation. However, donor organ shortage remains a major barrier for many patients. In recent years, techniques for maintaining lungs ex vivo for evaluation and short-term (<12h) resuscitation have come into more widespread use in an attempt to expand the donor pool. In parallel, progress in whole organ engineering has provided the potential perspective of patient derived grafts grown on demand. As both of these strategies advance to more complex interventions for lung repair and regeneration, the need for a long-term organ culture system becomes apparent. Herein we describe a novel clinical scale bioreactor capable of maintaining functional porcine and human lungs for at least 72 hours in isolated lung culture (ILC). The fully automated, computer controlled, sterile, closed circuit system enables physiologic pulsatile perfusion and negative pressure ventilation, while gas exchange function, and metabolism can be evaluated. Creation of this stable, biomimetic long-term culture environment will enable advanced interventions in both donor lungs and engineered grafts of human scale.

Patients with short bowel syndrome lack sufficient functional intestine to sustain themselves with enteral intake alone. Transplantable vascularized bioengineered intestine could restore nutrient absorption. Here we report the engineering of humanized intestinal grafts by repopulating decellularized rat intestinal matrix with human induced pluripotent stem cell-derived intestinal epithelium and human endothelium. After 28 days of in vitro culture, hiPSC-derived progenitor cells differentiate into a monolayer of polarized intestinal epithelium. Human endothelial cells seeded via native vasculature restore perfusability. Ex vivo isolated perfusion testing confirms transfer of glucose and medium-chain fatty acids from lumen to venous effluent. Four weeks after transplantation to RNU rats, grafts show survival and maturation of regenerated epithelium. Systemic venous sampling and positron emission tomography confirm uptake of glucose and fatty acids in vivo. Bioengineering intestine on vascularized native scaffolds could bridge the gap between cell/tissue-scale regeneration and whole organ-scale technology needed to treat intestinal failure patients.