Splenomegaly is a frequent finding in patients with liver disease due to venous congestion as a consequence of portal hypertension; hypersplenism is characterized by congestive splenomegaly and secondary a reduction of erythrocytes, leucocytes and/or platelets due to splenic pooling/sequestion . In patients with poor liver function a splenectomy is often not possible. Alternatively, mimimal invasive procedures such as partial splenic embolisation and transjugular intrahepatic portosystemic shunt (TIPS) implantation are used to reduce portal venous pressure [2, 4, 5]. Radiofrequency ablation (RFA) and microwave (MW) ablation of splenic parenchyma – as less radical techniques–are also applicable in symptomatic congestive splenomegaly [6, 7]. None of these procedures provide convincing results and are all associated with the potential of major complications including splenic infarction, abscess formation, pain, bleeding and sepsis.
Splenic irradiation is a well-established palliative treatment option in patients with lympho-and myeloproliferative malignancies presenting with symptomatic splenomegaly [1, 8]. In addition, radiotherapy is known to be effective in a large variety of degenerative and hyperproliferative benign conditions . In terms of hypersplenism due to splenic congestion the value of radiotherapy is limited to two case series as illustrated below [10, 11].
In all patients with precedent splenic pain treated with radiotherapy we observed a long-term pain relief. In addition we found an improvement of hematological parameters, particularly of platelets in four patients and a slightly decrease of spleen size of about 10% in two patients.
Until now, only two case series are reported in the Anglophone literature, which analyse 5 and 8 patients respectively treated with splenic irradiation for symptomatic congestive splenomegaly [10, 11]. Both achieved outcomes similar to ours in terms of pain relief (Kenawi: 8 of 8 patients [100%]; Liu: 2 of 2 [100% of the patients with precedent pain]; 3 patients had precedent painless splenomegaly) and increase of platelets (Kenawi: 3 of 8 patients; Liu: 5 of 5 patients) after splenic irradiation. The mean follow-up of 4 and 19 months respectively was quite short compared to 20 months in our analysis. The applied total dose was significantly higher with 12 Gy in 8 fractions (single doses of 1.5 Gy, five times a week) in the serie of Liu et al. , while Kenawi et al.  applied different total doses from 3.0 to 23.0 Gy (mean total dose approximately 12 Gy; single doses ranged from 0.5 to 1.5 Gy). Moreover, in all reported patients there was no correlation between clinical response and change in spleen size observed.
Osorio et al.  reported another case of painful splenomegaly due to Eisenmenger’s syndrome. Their patient was treated with splenic irradiation with a very high total dose of 40 Gy and daily single doses of 2.5 Gy. The patient achieved good pain relief and marked reduction of spleen size but he died 4.5 months after radiotherapy due to complications of acute cholecystitis. However, very high-dose splenic irradiation as performed in this case is debatable and seems inappropriate to achieve symptom control in such a palliative setting.
For splenic irradiation in lympho-and myeloproliferative malignancies a large variation of different schedules is used with single doses from 0.1 to 2 Gy and total doses of 0.3–16 Gy and no consensus recommendations exist concerning total dose and fractionation regimes until now [1, 13]. In our series we showed that a significant lower dose of 3.0 Gy is sufficient to achieve suitable pain relief and hematological response compared to higher doses (12 Gy and more) reported by Kenawi and Liu et al. In addition, prescription of lower doses preserves the potential of re-irradiation in cases of treatment failure in this palliative setting, as it was seen in patient 3.
The exact mechanism how splenic irradiation exerts its effects in splenomegaly is poorly understood. While splenic irradiation is usually considered as a local treatment only with direct effects on the spleen, it also induces systemic effects, which includes problematic symptoms and life-threatening pancytopenia; mechanisms believed to contribute to these effects include direct radiation-induced cell death, immune modulation via selective reduction in lymphocyte subsets, and cytokine induction [13, 14].
So far, in accordance with the literature data we observed in our case series no clinically relevant early or late toxicity. Particularly, no hematologic toxicities > CTC II° occurred.