gms | German Medical Science

Objective: Gross total removal (GTR) of primary CNS lymphoma (PCNSL) has been discouraged due to the diffuse nature of the disease and lack of oncological impact. Recently, the role of neurosurgical resection has drawn new attention.

Method: A retrospective analysis of patients treated for PCNSL from 2008 to 2014 was performed. MRI characteristics and post-surgical survival was correlated to clinical and therapy modalities with special emphasis on the extent of surgical resection.

Results: 34 patients with PCNSL were identified, 62% were male. Mean age at diagnosis was 66,4 ± 12,2 years with no gender difference. 71% revealed a solitary tumor. MRI was suggestive of PCNSL in only 50%. In 11 patients, MRI revealed an atypical appearance and diagnosis was unclear. 6 patients were misdiagnosed as brain metastasis (50%) or meningioma. In 25 patients open or stereotactical biopsy was done. In 9 patients gross total resection was performed, of these, 4 harbored more than one lesion. Resection therefore was regarded as subtotal. Next to corticosteroids, 44% received high-dose MTX-based chemotherapy and whole brain radiation with 45Gy. 32% received chemotherapy and 18% irradiation only. In 2 patients no adjuvant therapy was given.

Mean follow-up time was 22 months, 11 patients died. Mean OS was 27,06 months. Survival was statistically dependent on the kind of adjuvant therapy, with longest OS in patients receiving combined radiochemotherapy or chemotherapy only (p=0.0224). There was no difference in OS between patients with GTR compared to subtotal resection. However, biopsied patients had inferior OS compared with gross-total resected patients. 6, 12 and 24 months survival was 100%, 86% and 86% for GTR resection and 82%, 61% and 42% for biopsied patients, respectively. Survival and the impact of the extend of surgical resection was not influenced by age, gender, pre- or postop KPS, number of lesions as well as adjuvant therapy. Astonishingly, in patients with correct presurgical diagnosis of lymphoma, OS survival was significantly longer than in misdiagnosed patients (p=0.037).

Conclusions: The role of surgery in the treatment of PCNSL has to be reconsidered and the extent of resection should be stratified in PCNSL trials. Despite the histological homogeneity of PCNSL, these tumors demonstrate different radiological characteristics and might therefore even harbor different biological attributes, which could be assessed in moleculargenetic analyses.