Spleen Irradiation Research Articles

Microscopic features of the regeneration of white pulp in autotransplanted spleens in rats.

The process of regeneration of white pulp in autotransplanted splenic tissue, implanted into a pocket made by the greater omentum in rats, was investigated histologically and immunohistochemically. Three days after transplantation, almost all implants were necrotic. At day 7, viable splenic tissue had gradually regenerated at the periphery of the implants. At day 10, lymphocytes accumulated around the arterioles. The accumulations resembled the periarteriolar lymphoid sheath of normal spleens in structure, but consisted mainly of B-lymphocytes, with a few scattered T-lymphocytes. However, by week 2, the localization peculiar to T- and B-lymphocytes became definite, and follicular dendritic cells were simultaneously observed in the lymph follicles. This regeneration of the white pulp in the autotransplanted spleens differed from the formation of the white pulp during ontogeny and during recovery after spleen irradiation.

Effects of in vivo ultrasound hyperthermia on natural killer cell cytotoxicity in the hamster.

The effects of in vivo ultrasound irradiation of the spleen on immunological functions were assessed with an in vitro natural killer (NK) cell cytotoxic assay. Anesthetized hamsters were exposed to 1 MHz ultrasound at intensity levels currently being used clinically for therapeutic diathermy and hyperthermia (1-5 W/cm2, for 500 sec with constant beam scanning). Hyperthermic levels in the spleen ranged from 38-43 degrees C. Significant depression of natural killer (NK) cell activity was seen 4 h after spleen irradiation as compared to sham irradiated and normal animals. A return towards normal levels was observed in experimental groups at 24 h after exposure. Sham and normal animals were not significantly different in NK activity, indicating no significant stress-related immunosuppressive effects due to handling. Differential leukocyte counts taken for each exposure condition showed significant lymphopenia at 4, 8, and 16 h after exposure, near normal levels at 24 h, and complete recovery by 48 h. The number of circulating mononuclear cells at 4 h showed a dose-related suppression as the exposure intensities were increased.

Spleen irradiation in chronic lymphocytic leukemia (CLL): Palliation in patients unfit for splenectomy

In 22 patients with CLL given 30 courses of spleen irradiation, 23 responses were observed (77%, 95% confidence limits, 58-90%). Response was defined as reduction in palpable spleen size accompanied by relief of symptoms (pain, abdominal discomfort, and sweating) or improvement in hypersequestration or hemolytic anemia. Reduction in leukocyte count alone was not regarded as response. All responses were partial. The median response duration was 1 year. Subsequently, three patients underwent splenectomy. The median survival from the beginning of spleen irradiation was 2.5 years (range: 1 month-greater than 5 years). Only six patients had minor side effects from the gastrointestinal tract. The hematologic effect was most pronounced on the white blood cell count, but also the platelet count was affected. It is concluded that spleen irradiation is a gentle and effective alternative in CLL patients suffering from splenomegaly (pain and hypersplenism), refractory to chemotherapy and glucocorticosteroids and unfit for splenectomy. Splenic irradiation may also be used with benefit preoperatively before splenectomy in patients with excessive splenomegaly and hypersplenism.

Five-year results of the E.O.R.T.C. randomized study of splenectomy and spleen irradiation in clinical stages I and II of Hodgkin's disease

A controlled clinical trial was carried out on patients with clinical stages I and II of Hodgkin's disease by the E.O.R.T.C. from 1972 to 1976. Three hundred patients with supradiaphragmatic presentation were assigned at random into two groups, one treated by spleen irradiation, the other by splenectomy. All patients received a mantle field irradiation as well as a para-aortic lymph node irradiation. The actuarial survival rates and relapse-free survival rates at five years were, respectively, 90 and 62% in the group treated by spleen irradiation and 90 and 67% in the group splenectomized. The efficiency of the two treatments is therefore identical. In the group submitted to staging laparotomy, all patients received the same treatment without taking into account the results of the splenectomy and of the lymph node biopsy. Of 107 patients without spleen or lymph node involvement 18 relapsed (17%); of 33 patients with spleen involvement 14 relapsed (42%). Relapse in non-irradiated lymph node territories (iliac and inguinal areas) were fifteen-fold more frequent in patients with spleen involvement, whereas extra nodal relapses were about twice as frequent in patients with spleen involvement than in patients without spleen involvement. Patients with mixed cellularity or lymphoid depletion histological types received long term adjuvant chemotherapy either by Vinblastine + Procarbazine or by Vinblastine alone. The 5-year relapse rate was 12% with both chemotherapeutic regimens.

UTILIZATION OF A SCORE SYSTEM IN THE PROGNOSIS OF ACUTE LYMPHOCYTIC LEUKEMIA (ALL) IN CHILDHOOD

The purpose of this study was to develop a scoring system which would assist in the prognosis of ALL In childhood. The following system was utilized retrospectively on the initial clinical data on 41 children with ALL who received systemic combination chemotherapy and central nervous system (CNS) therapy ± organ (liver, kidneys and spleen) irradiation. Numerical values yielded total scores ranging from -2 to +3 for each of 41 patients. Mean scores for those who succeeded (i.e. continuous remission of at least 2½ years) was significantly different at the 0.005 level compared to those who failed (i.e. relapse or death). The implication of this is that such a scoring system (not incorporating the WBC) when used in conjunction with the white cell count may more accurately determine the prognosis of ALL in childhood.

Splenic Irradiation in Chronic Granulocytic Leukemia: Changes in Leukocyte Values

Thirteen patients with chronic granulocytic leukemia were given 28 separate irradiations to the spleen for the treatment of their disease. The radiation was given as a single dose that ranged between 100 and 700 rads. The changes in the circulating white blood cell (WBC) count could be represented by the expression $N=B_{0}+S_{0}(e^{-\beta t})$ where N is the number of WBC per mm3 of blood at day t; S0 is the number of WBC, at time zero, originating from the spleen; and B0 is the number of WBC stemming from nonirradiated parts of the body, mostly bone marrow. The disappearance rate β, determined by an indirect method, indicated that S0 cells were leaving the blood with a half-time of 4.5 days. The number of S0 cells could be calculated a posteriori by the expression $S_{0}=(N_{0}-N)/(1-e^{-\beta t})$, where N0 is the number of WBC before spleen irradiation and N the number of WBC at t days after irradiation.

Spleen irradiation in secondary hypersplenism.

The purpose of this study was to determine the effect of splenic irradiation on the hematologic manifestations of hypersplenism: hemolytic anemia, granulocytopenia, and thrombocytopenia.Eight patients with hypersplenism secondary to various diseases had their spleens irradiated with doses of between 700 and 2,000 r in a period of 8 to 17 days. Although most of the patients had some clinical improvement, related particularly to the reduction in spleen size, the hypersplenic manifestations showed little response to the treatment. Only 1 patient had a lasting remission of hemolytic anemia, and even this was not clearly attributable to splenic irradiation.Splenectomy was effective in controlling hypersplenism, and, when feasible, is the treatment of choice for this condition.

Blood coagulation and hemostasis by spleen irradiation in gynecology

Blood coagulation and hemostasis by spleen irradiation in gynecology