Total‐Body Irradiation in the Conditioning Regimens for Autologous Stem Cell Transplantation in Lymphoproliferative Diseases

Biophysical Characterization of the Leukemic Bone Marrow Vasculature Reveals Benefits of Neoadjuvant Low-Dose Radiation Therapy

PURPOSE

Although vascular alterations in solid tumor malignancies are known to decrease therapeutic delivery, the effects of leukemia-induced bone marrow vasculature (BMV) alterations on therapeutic delivery are not well known. Additionally, functional quantitative measurements of the leukemic BMV during chemotherapy and radiation therapy are limited, largely due to a lack of high-resolution imaging techniques available preclinically. This study develops a murine model using compartmental modeling for quantitative multiphoton microscopy (QMPM) to characterize the malignant BMV before and during treatment.

METHODS AND MATERIALS

Using QMPM, live time-lapsed images of dextran leakage from the local BMV to the surrounding bone marrow of mice bearing acute lymphoblastic leukemia (ALL) were taken and fit to a 2-compartment model to measure the transfer rate (Ktrans), fractional extracellular extravascular space (νec), and vascular permeability parameters, as well as functional single-vessel characteristics. In response to leukemia-induced BMV alterations, the effects of 2 to 4 Gy low-dose radiation therapy (LDRT) on the BMV, drug delivery, and mouse survival were assessed post-treatment to determine whether neoadjuvant LDRT before chemotherapy improves treatment outcome.

RESULTS

Mice bearing ALL had significantly altered Ktrans, increased νec, and increased permeability compared with healthy mice. Angiogenesis, decreased single-vessel perfusion, and decreased vessel diameter were observed. BMV alterations resulted in disease-dependent reductions in cellular uptake of Hoechst dye. LDRT to mice bearing ALL dilated BMV, increased single-vessel perfusion, and increased daunorubicin uptake by ALL cells. Consequently, LDRT administered to mice before receiving nilotinib significantly increased survival compared with mice receiving LDRT after nilotinib, demonstrating the importance of LDRT conditioning before therapeutic administration.

CONCLUSION

The developed QMPM enables single-platform assessments of the pharmacokinetics of fluorescent agents and characterization of the BMV. Initial results suggest BMV alterations after neoadjuvant LDRT may contribute to enhanced drug delivery and increased treatment efficacy for ALL. The developed QMPM enables observations of the BMV for use in ALL treatment optimization.

Cardiovascular disease following hematopoietic stem cell transplantation: Pathogenesis, detection, and the cardioprotective role of aerobic training

Advances in hematopoietic cell transplantation (HCT) techniques and supportive care strategies have led to dramatic improvements in relapse mortality in patients with high-risk hematological malignancies. These improvements, however, conversely increase the risk of late-occurring non-cancer competing causes, mostly cardiovascular disease (CVD). HCT recipients have a significantly increased risk of CVD-specific mortality, including elevated incidence of coronary artery disease (CAD), cerebrovascular disease, and heart failure (HF) compared to age-matched counterparts. Accordingly, there is an urgent need to identify techniques for the detection of early CVD in HCT patients to inform early prevention strategies. Aerobic training (AT) is established as the cornerstone of primary and secondary disease prevention in multiple clinical settings, and may confer similar benefits in HCT patients at high-risk of CVD. The potential benefits of AT either before, immediately after, or in the months/years following HCT have received limited attention. Here, we discuss the risk and extent of CVD in adult HCT patients, highlight novel tools for early detection of CVD, and review existing evidence in oncology and non-oncology populations supporting the efficacy of AT to attenuate HCT-induced CVD. This knowledge can be utilized to optimize treatment, while minimizing CVD risk in individuals with hematological malignancies undergoing HCT.

LACE-conditioned autologous stem cell transplantation for relapsed or refractory diffuse large B-cell lymphoma: treatment outcome and risk factor analysis from a single centre

High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is a recognized treatment option for patients with relapsed diffuse large B-cell lymphoma. We have analysed 51 patients who underwent ASCT after LACE (lomustine (CCNU), cytarabine (Ara-C), cyclophosphamide, etoposide) conditioning for relapsed (n = 34, 67%) or primary refractory (n = 17, 33%) diffuse large B-cell lymphoma. With a median follow-up of 60 months (range 2-216) the probabilities of overall survival (OS) and progression-free survival (PFS) at 5 years were 47 and 42%, respectively. The cumulative treatment-related mortality was 10% (n = 5). Probabilities for OS and PFS at 5 years were 56 and 50% for patients with chemosensitive and 29 and 27% for patients with chemorefractory disease. In multivariate analysis abnormal pre-ASCT levels of C-reactive protein (>5 mg/L) were identified as a risk factor for worse OS, whereas abnormal pre-ASCT levels of C-reactive protein and chemoresistance predicted inferior PFS. LACE followed by ASCT is an effective treatment for approximately half of patients with chemosensitive relapsed diffuse large B-cell lymphoma, and a proportion of chemorefractory patients also benefit.

Bone mass and microarchitecture of irradiated and bone marrow-transplanted mice: influences of the donor strain

Total body irradiation and bone marrow transplantation induced dramatic trabecular bone loss and cortical thickening in mice. Transplanted cells were engrafted in bone marrow, along trabeculae, and in periosteal and endosteal envelopes. None of the osteocytes were of donor origin. Bone microarchitecture of transplanted mice changed to tend toward the donor phenotype.

INTRODUCTION

Osteopenia and osteoporosis are complications of bone marrow transplants (BMT) attributed to related chemotherapy. However, the specific influence of total body irradiation (TBI) is unknown.

METHODS

We investigated the effects of TBI and BMT on bone mass and microarchitecture by micro-CT. Eighteen C57Bl/6 (B6) mice receiving lethal TBI had a BMT with marrow cells from green fluorescent protein--transgenic-C57Bl/6 (GFP) mice. Transplanted (T(GFP)B6), B6, and GFP mice were euthanized 1, 3, and 6 months after BMT or at a related age.

RESULTS

T(GFP)B6 presented a dramatic bone loss compared with B6 and did not restore their trabecular bone mass over time, despite a cortical thickening 6 months after BMT. Serum testosterone levels were not significantly reduced after BMT. During aging, GFP mice have less trabeculae, thicker cortices, but a narrower femoral shaft than B6 mice. From 3 months after BMT, cortical characteristics of T(GFP)B6 mice differed statistically from B6 mice and were identical to those of GFP mice. GFP(+) cells were located along trabecular surfaces and in periosteal and endosteal envelopes, but none of the osteocytes expressed GFP.

CONCLUSION

Our findings suggest that engrafted cells did not restore the irradiation-induced trabecular bone loss, but reconstituted a marrow microenvironment and bone remodeling similar to those of the donor. The effects of irradiation and graft on bone remodeling differed between cortical and trabecular bone.

Study of conditioning regimens with or without high-dose radiotherapy before autologous stem cell transplantation for treating aggressive lymphoma

The aim and objective of the study is to compare the efficacy of conditioning regimens with or without high-dose radiotherapy for treating aggressive non-Hodgkin's lymphoma (NHL). Eighty-nine aggressive NHL patients who underwent high-dose therapy in combination with autologous stem cell transplantation (HDT/ASCT) between 1993 and 2006 were retrospectively studied. HDT was either high-dose chemotherapy alone (CT) or high-dose chemoradiotherapy (CRT). Overall, 37 patients in CT group and 52 in CRT group. The median radiotherapy DT in CRT group was 8 Gy. The median count of reinfused CD34+ cells was 6.26 x 10(6) and 22.16 x 10(6) cells/kg, respectively (p < 0.001). The median time of leukocyte engraftment was 11 days in CT group and 13 days in CRT group (p = 0.003), and the median platelet engraftment time was 12 days in CT group and 11 days in CRT group (p = 0.305). The median event-free survival (EFS) was 102 and 84 months in CT and CRT groups, respectively (p = 0.783), and the median overall survival (OS) was 102 and 121 months in CT and CRT groups, respectively (p = 0.857). Prolonged hospitalization favored EFS (p = 0.013) and OS (p = 0.011). In conclusion, when compared with CT, high-dose CRT does not improve prognosis.

Autologous stem cell transplantation using a modified TAM conditioning regimen for clinically aggressive non-Hodgkin's lymphoma

PURPOSE

High-dose chemotherapy (HDT) and autologous stem cell transplantation (ASCT) have been used for the treatment of clinically aggressive non-Hodgkin's lymphoma (NHL). However, the superiority of specific conditioning regimens has not yet been established. The present study evaluated the efficacy and toxicity of a conditioning regimen involving fractionated total body irradiation (TBI), and the use of Ara-C and melphalan (TAM) for clinically aggressive NHL.

MATERIALS AND METHODS

Between March 2002 and December 2004, 31 patients with aggressive NHL received fractionated TBI with a dose of 12 Gy over 3 days, and were administered 9 g/m(2) Ara-C and 100 mg/m(2) melphalan followed by autologous peripheral blood stem Cell Transplantation at the Catholic Hematopoietic Stem cell transplantation Center Korea. Patients that responded to first line chemotherapy and achieved complete remission (CR), or were in a first sensitive relapse were defined as having less advanced disease, while the other patients were defined as having more advanced disease.

RESULTS

Objective responses were obtained in 24 of 31 patients (77.4%), comprising complete remission in 19 patients (61.3%) and partial remission in 5 (16.1%) patients. The median follow-up time was 28 months (range 1 approximately 62 months). At 3 years, the overall survival and event-free survival (EFS) rates were 62.3% and 47.3%, respectively. Patients with less advanced disease and more advanced disease showed 3-year EFS rates of 73.3% and 22.5 %, respectively (p=0.006). Early (within the first 100 days) treatment-related mortality occurred in 3 (9.7%) patients. Of the 31 total patients, 15 (48.4%) developed grade 3 mucositis, 22 (70.9%) developed neutropenic fever, and two (6.5%) developed interstitial pneumonia syndrome>grade 3.

CONCLUSION

The modified TAM conditioning regimen and ASCT appear to be a feasible treatment regimen for clinically aggressive NHL, particularly for patients with less advanced disease.

Cataracts in patients receiving stem cell transplantation after conditioning with total body irradiation

One hundred and ninety-three patients with hematological malignancies and a follow-up > or =1 year, treated with stem cell transplantation (45 autologous, 99 allogeneic T cell-depleted matched, 49 allogeneic T cell-depleted mismatched) from July 1985 to May 1998, were considered evaluable for the development of cataracts. Total body irradiation (TBI), administered either according to a hyperfractionated scheme (HTBI) or in a single dose (STBI), was employed in the conditioning regimens. HTBI was prescribed in 94% of patients undergoing allogeneic matched transplant, while STBI was used in 71% of patients receiving allogeneic mismatched and in all patients undergoing autologous transplant. The median follow-up was 7.56 years in the HTBI and 3.02 years in the STBI group. Among the different risk factors analyzed by univariate analysis only the TBI scheme and type of transplant reached statistical significance (P < 0.0001 and P < 0.001, respectively). By multivariate analysis only the TBI scheme was an independent factor for cataract development (STBI vs HTBI RR 7.2; P < 0.01). Our results showed that STBI is more cataractogenic than HTBI. The incidence of cataract we observed was among the lowest described in the literature. T cell depletion, because it prevents graft-versus-host disease and reduces the protracted use of post-transplant steroids, explains the results we obtained.