Splenic irradiation before bone marrow transplantation for chronic myeloid leukaemia. Chronic Leukaemia Working Party of the European Group for Blood and Marrow Transplantation (EBMT)

Pre-transplant Splenic Irradiation in Patients with Myeloproliferative Neoplasms

Purpose

Allogeneic hematopoietic cell transplantation (HCT) serves as the only curative treatment option for patients with myelofibrosis and other myeloproliferative neoplasms. Splenomegaly commonly manifests in patients with myeloproliferative neoplasms and can lead to delayed or poor engraftment, increased transfusion burden, and worse survival. Methods to decrease the effect of splenomegaly include splenectomy and splenic irradiation. We sought to report on clinical outcomes for patients treated with splenic irradiation as part of their transplant conditioning.

Methods and Materials

Patients with splenomegaly measuring greater than 22 cm were referred for splenic irradiation. They received radiation to the entire spleen to 10 Gy in 5 fractions using 3-dimensional conformal radiation with anteroposterior/posteroanterior or opposed tangent fields. Blood counts were monitored closely on treatment. Changes in splenic size were measured using first and last treatment image guided radiation therapy and pre- and posttransplant diagnostic imaging.

Results

Seventeen patients completed pretransplant splenic irradiation between 2012 and 2021. Median platelet, white blood cell, and hemoglobin levels decreased on treatment. One patient required platelet transfusion and 3 required packed red blood cell transfusions. Mean decrease in spleen size during radiation was -8.5% in the craniocaudal dimension. Prolonged decreases, measured 2 to 12 months after transplant, averaged 14.64%. All patients engrafted. Fourteen (82.4%) were alive at time of analysis with median follow-up of 4.2 years from hematopoietic cell transplantation.

Conclusions

Splenic irradiation offers a safe method of managing significant splenomegaly as part of transplant conditioning. Transplant outcomes in this series were excellent. Prospective data may be beneficial to determine the absolute benefit of this addition to pretransplant conditioning in this patient population.

Radiotherapy for symptom palliation of splenomegaly in patients with haematological malignancies

Splenomegaly severely compromises the quality of life of those affected. The aim of the present study was to describe the clinical characteristics of patients with haematological disorders who receive radiotherapy for splenomegaly, particularly focusing on the changes in spleen volume. The present study conducted a retrospective analysis of consecutive patients with haematological disorders who underwent splenic radiotherapy with palliative intent at the Department of Radiology of the University of Tokyo Hospital between June 2008 and June 2019. Pre- and post-radiotherapy spleen volumes were measured from computed tomography images. A total of 8 patients (5 men and 3 women) with a median age of 59 years (range, 46-76 years) were included. The median total prescription and fractional doses were 4.5 Gy (range, 1.5-10 Gy) and 0.78 Gy (range, 0.5-2.0 Gy), respectively. A total of 5 patients (62.5%) experienced a reduction in spleen volume. The mean ± SD spleen sizes pre- and post-radiotherapy were 1,887±1,011 and 1,368±577 ml, respectively. The mean variation rate in spleen volume was -19.1±24.7%, and the case with the most notable improvement in the present study exhibited a -52.4% change. Of the 5 patients who experienced pain prior to radiotherapy, 3 achieved pain relief, 1 did not experience any change and 1 patient was not assessed post-radiotherapy. Therefore, the findings of the present study revealed that palliative radiotherapy for splenomegaly may achieve symptom palliation and radiological volumetric effects in patients with haematological disorders.

Splenic irradiation as a component of a reduced-intensity conditioning regimen for hematopoietic stem cell transplantation in myelofibrosis with massive splenomegaly

Primary myelofibrosis is a hematologic neoplasm characterized by bone marrow fibrosis and extramedullary hematopoiesis. A similar clinical condition can occur at late stage of myeloproliferative neoplasms such as polycythemia vera and essential thrombocythemia. Although allogeneic hematopoietic stem cell transplantation (HSCT) is currently the only curative strategy for both conditions, massive splenomegaly frequently observed in patients with myelofibrosis is considered to be a risk factor for graft failure or engraftment delay after transplantation. A proportion of patients can benefit from splenectomy before transplantation but such procedures have been associated with substantial surgical morbidity. Here, we report two elderly patients with myelofibrosis who received scheduled splenic irradiation for massive splenomegaly immediately prior to allogeneic HSCT instead of undergoing splenectomy. The first patient was a 60-year-old woman who received peripheral blood stem cell transplantation for post-essential thrombocythemia myelofibrosis from an HLA-identical sibling; the second patient was a 60-year-old man who received unrelated bone marrow transplantation for primary myelofibrosis. After receiving fractionated splenic irradiation and fludarabine-based reduced-intensity conditioning regimens, these patients showed remarkable reduction of their splenomegaly at the time of transplantation. They attained successful donor cell engraftment without severe complications related to splenic irradiation, while improvement in splenomegaly was durable. Our experience suggests that splenic irradiation before allogeneic HSCT might be a safe and effective alternative to splenectomy for myelofibrosis patients with massive splenomegaly in terms of reducing the risk of surgical morbidity.

Survival of patients with chronic myelocytic leukemia: comparisons of estimates from clinical trial settings and population-based cancer registries

INTRODUCTION

The survival of patients with chronic myelocytic leukemia (CML) has improved during the past decades. However, there have been discrepancies between results reported from clinical trials and population-based studies. We aimed to elucidate the extent of these discrepancies.

METHODS

We examined the 5-year survival rate of patients in clinical trials of CML treatment and compared these results with the survival of patients in the general population using the Surveillance, Epidemiology, and End Results (SEER) database, correcting for differences in the age structure of the patient populations.

RESULTS

Twenty-nine trials were identified for data extraction. The survival rate calculated from SEER data was lower than the survival rate in clinical trials in the corresponding period, with differences of 2.1%-50.7%. Age-adapted survival was similar for four trials, but differences up to 35.8% were seen in most. Limitations of the study include the lack of information on chemotherapy in the SEER database and possible heterogeneity of cases.

DISCUSSION

The survival rate in clinical trials of CML treatment is higher than the survival rate of all patients with CML. We speculate that the difference may be a result of access to better medications, selection of healthier patients for trials, and the time necessary for adoption of new treatments. This finding underscores the need for population-based studies to give a more realistic idea of survival for patients with a given malignancy in the general population.

Splenic Radiation and Double-Filtration Plasmapheresis in Crossmatch-Positive Live Renal Transplantation

Double-filtration plasmapheresis (DFPP) and splenectomy prior to transplant is used in a few centers for high-risk transplantations. We undertook a prospective study to examine the outcome of 16 kidney transplantations in crossmatch-positive patients using splenic radiation and DFPP as pretransplant immunomodification procedures. All patients received a single dose of Zenapax (50 mg intravenously [IV] 8 hours before transplant), before treatment with cyclosporine, mycophenolate mofetil, and steroids immediately posttransplant. Follow-up ranged from 3 months to 1 year. Hyperacute rejection requiring graft nephrectomy was necessary in one patient; acute rejection, which was seen in three patients, was reversed with five doses of Iort3 at 1-month posttransplant the mean creatinine was 1.3 +/- 0.6 mg/dL in patients who did not have rejection and 1.9 +/- 0.3 mg/dL in the three patients who had acute rejection. Six patients were switched from cyclosporine to sirolimus. At the end of 3 months the mean creatinine levels was 1.4 +/- 0.3 mg%. The infections included oral candida (n = 2), urinary tract infection (UTI) (n = 1), bacterial pneumonia (n = 1), and herpes zoster (n = 1). With the advent of modern immunosuppressants, pretransplant immunomodification with DFPP and splenic radiation is safe and effective. Splenic radiation is devoid of surgical risk and more acceptable to patients.

Long-term follow-up of allogeneic bone marrow transplantation after reduced-intensity conditioning in patients with chronic myelogenous leukemia in the chronic phase

Although allogeneic transplantation is a curative therapy for chronic myelogenous leukemia (CML), treatment-related mortality is still a major cause of death after transplantation, especially in older patients. We investigated the safety and efficacy of reduced-intensity conditioning consisting of low-dose (600 cGy) total body irradiation and cytosine arabinoside (1 g/m2) together with a continuous infusion of granulocyte colony-stimulating factor and cyclophosphamide (120 mg/kg) in patients with CML in the chronic phase. Fractionated splenic irradiation (5 Gy) was also administered as part of the conditioning treatment. Eight patients older than 40 years underwent allogeneic bone marrow transplantation from an HLA-matched sibling following this conditioning. Regimen-related toxicities (equal to or greater than grade III) were not observed. Rapid restoration of 100% donor chimerism was confirmed by fluorescence in situ hybridization methods in 5 sex-mismatched transplant recipients. One patient died from severe acute graft-versus-host disease and another from Pneumocystis carinii pneumonia early in the course of transplantation. A sustained engraftment was achieved in 5 long-term survivors; in 1 case, the graft was rejected but the Philadelphia chromosome and BCR/ABL-negative autologous hemopoiesis were restored. After a minimum follow-up period of 60 months, 6 patients, including the patient with restored autologous hemopoiesis, were still alive and in remission with 100% donor chimerism. Six years after the transplantation, 1 patient experienced a cytogenetic relapse, which was successfully treated with donor lymphocyte infusions. In summary, this reduced-intensity conditioning resulted in a cure with markedly reduced regimen-related toxicities in this relatively older cohort of patients with CML.