Low-dose splenic irradiation in symptomatic congestive splenomegaly: report of five cases with literature data

The relationship between splenic dose and radiation-induced lymphopenia

Lymphocytes, which are highly sensitive to radiation, play a crucial role in the body's defense against tumors. Radiation-induced lymphopenia has been associated with poorer outcomes in different cancer types. Despite being the largest secondary lymphoid organ, the spleen has not been officially designated as an organ at risk. This study hypothesizes a connection between spleen irradiation and lymphopenia and seeks to establish evidence-based dosage limits for the spleen. We retrospectively analyzed data from 96 patients with locally advanced gastric cancer who received postoperative chemoradiotherapy (CRT) between May 2010 and May 2017. Complete blood counts were collected before, during and after CRT. We established a model for predicting the minimum absolute lymphocyte count (Min ALC) and to investigate potential associations between spleen dosimetric variables and Min ALC. The median follow-up was 60 months. The 5-year overall survival (OS) and disease-free survival (DFS) were 65.2% and 56.8%, respectively. The median values of pre-treatment ALC, Min ALC and post-treatment ALC were 1.40 × 109, 0.23 × 109 and 0.28 × 109/L, respectively. Regression analysis confirmed that the primary tumor location, number of fractions and spleen V5 were significant predictors of Min ALC during radiation therapy. Changes in ALC (ΔALC) were identified as an independent predictor of both OS and DFS. Spleen V5 is an independent predictor for Min ALC, and the maximum dose of the spleen is associated with an increased risk of severe lymphopenia. Therefore, these doses should be restricted in clinical practice. Additionally, ΔALC can serve as a prognostic indicator for adjuvant radiotherapy in gastric cancer.

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.

The role of bone marrow and spleen irradiation in the development of acute hematologic toxicity during chemoradiation for esophageal cancer

Purpose

The purpose of this study was to determine the impact of splenic and thoracic bone marrow irradiation on hematologic toxicity in the setting of chemoradiation therapy for esophageal cancer.

Methods and materials

We analyzed 60 patients with carcinoma of the distal esophagus or gastroesophageal junction who received concurrent chemoradiation in the preoperative or definitive setting. Dosimetric and volumetric parameters were calculated for the spleen, thoracic spine, and posterior ribs. The primary endpoint was grade ≥3 hematologic toxicity (HT3+). Associations were assessed using logistic and linear regression models.

Results

Twenty-one patients (35%) experienced HT3+, including 18 patients with leukopenia and 5 with thrombocytopenia. Higher spleen V5-V20 was correlated with a lower risk of HT3+ on multivariable analysis (odds ratio: 0.83 per 10 cm³ increase in V10; P = .013). A dose-dependent decrease in spleen volume was observed after radiation therapy, and a greater decrease was independently associated with a lower risk of HT3+ (odds ratio: 0.93 per 1% volume decrease; P = .014). Dosimetric parameters of the thoracic spine were not significantly associated with HT3+.

Conclusions

A greater decrease in spleen size after radiation therapy and a higher spleen V5-V20 were independently associated with a lower risk of severe hematologic toxicity. Splenic irradiation may mitigate leukopenia associated with chemoradiation therapy.

Treatment of symptomatic splenomegaly with low doses of radiotherapy: Retrospective analysis and review of the literature

OBJECTIVES

To evaluate the effectiveness of low doses of radiation therapy for symptomatic splenomegaly in malignant and benign diseases.

PATIENTS AND METHODS

5 patients with symptomatic splenomegaly were treated with low doses of radiation in our centre (January 2008-December 2016). 4/5 patients had malignant neoplasia (acute myeloid leukemia, non Hogdkin lymphoma and prolymphocytic B cell leukemia) and splenomegaly was caused by extramedullary hematopoiesis. 1/5 patient had benign disease (HBV liver cirrhosis) and splenomegaly was caused by vascular ectasia. Median age was 73 years (range 61-86 years). There were 4 females and 1 male. These patients had exclusively splenic pain or abdominal discomfort in 20%, exclusively cytopenias 40% and both 40%. Patients needed radiation therapy for symptomatic control. Dose per fraction was 0.5 Gy every two days; total dose initially prescribed 10 Gy. IGRT were performed in all patients to ensure an appropriate position and to adapt the treatment volume to the changes in the spleen volume along the treatment. Median craneocaudal length size of the spleen was more than 26 cm (range 15.2-34.9 cm).

RESULTS

Median radiation doses were 4.85 Gy (range 2.5-10). Median craneocaudal spleen size reduction was 4.6 cm (0-8 cm). Splenic pain and abdominal disturbances improved in all patients. Median increase of haemoglobin and platelets levels was 1.6 mg/dl and 27.950 cells respectively in the first week after the end of radiotherapy.One patient had to interrupt her treatment due to grade II neutropenia. No other toxicities were described. With a median follow-up of 39 months (16-89 months), only one recurrence was described at 24 months and consisted of thrombocytopenia. The patient received a second course of radiotherapy with excellent response.

CONCLUSION

Low doses of radiation therapy for treatment of symptomatic splenomegaly were effective, with a low rate of side effects. Splenic pain and abdominal discomfort completely improved and cytopenias rised to secure levels.