Clinical treatment of radiotherapy tissue damage by lipoaspirate transplant: a healing process mediated by adipose-derived adult stem cells.

Background: There is evidence that stem cells contribute to the restoration of tissue vascularization and organ function. The objective of this study was to assess the presence of adipose-derived adult stem cells left in their natural scaffold in the purified lipoaspirate and to assess the clinical effectiveness of lipoaspirate transplantation in the treatment of radiation side effects.

Methods: This study was designed beginning with surgical procedures in 2002 and envisaging a continuous patient follow-up to 31 months. Twenty consecutive patients undergoing therapy for side effects of radiation treatment with severe symptoms or irreversible function damage (LENT-SOMA scale grade 3 and 4) were enrolled. Purified autologous lipoaspirates (60 to 120 cc) taken from a healthy donor site were administered by repeated low-invasive computer-assisted injection. Therapy outcomes were assessed by symptoms classification according to the LENT-SOMA scale, cytofluorimetric characterization, and ultrastructural evaluation of targeted tissue.

Results: In the isolated stromal vascular fraction of 2 cc of human lipoaspirate, cells with mesenchymal stem cell physical properties and immunophenotype were in average 1.07 +/- 0.5 percent (n = 4), with a clonogenic fraction of 0.139 percent. At least 1.02 x 10(3) colony-forming units-fibroblast were present in each lipoaspirate. Ultrastructure of target tissue systematically exhibited progressive regeneration, including neovessel formation and improved hydration. Clinical outcomes led to a systematic improvement or remission of symptoms in all evaluated patients, including otherwise untreatable patients exhibiting initial irreversible functional damage.

Conclusions: This surgical procedure is a low-invasive therapeutic approach for resolving the late side effects of radiotherapy. According to the proposed hypothesis of the ischemic nature of radiolesions, treatment with lipoaspirate transplantation is potentially extended to other forms of microangiopathies.