HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

Correspondence to:

BRIEF COMMUNICATIONS: W. Küker, T. Nägele, E. Thiel, M. Weller, and U. Herrlinger Primary central nervous system lymphomas (PCNSL): MRI response criteria revised Neurology 2005; 65: 1129-1131 [Abstract] [Full text] [PDF]

Correspondence: Submit a response to this article

Correspondence published:

Primary central nervous system lymphomas (PCNSL): MRI response criteria revised

Uwe Schlegel, Annika Jürgens, Hendrik Pels   (5 December 2005)

Reply from Authors

W. Kuker, Ulrich Herrlinger   (5 December 2005)

Primary central nervous system lymphomas (PCNSL): MRI response criteria revised 5 December 2005
Uwe Schlegel, Ruhr-University Bochum Universitätsstraße 150 , 44801 Bochum, Germany, Annika Jürgens, Hendrik Pels Send Correspondence to journal: Re: Primary central nervous system lymphomas (PCNSL): MRI response criteria revised uwe.schlegel{at}kk-bochum.de Uwe Schlegel, et al.	Küker et al propose revised response criteria for primary CNS lymphoma (PCNSL) after completion of tumor-directed therapy. [1] Of 68 patients with contrast enhancing lesion after methotrexate (MTX) therapy, they identified four with small lesions (5mm in diameter or “bandlike”) in the area of primary tumor, hemorrhage, biopsy or infection. The lesions were not further treated and did not show any change at 9, 24, 32 and 54 months follow-up. Such lesions may reflect “unconfirmed” complete remissions (CRu) and not residual tumor, as proposed by an international workshop on standards of baseline evaluation and response criteria for PCNSL. [2] The limits of residual lesion size as proposed by Küker et al are arbitrary. In their retrospective analysis, they do not include information on the 64/111 cases who met the criteria of partial remission (PR) and how decisions for either salvage therapy vs waiting were made in these cases. In a series of 65 patients treated with a combined systemic and intraventricular chemotherapy, patients who met the criteria of a PR were not treated with salvage therapy irrespective of residual tumor size. [3] From these cases(plus another 23 patients treated with the same regimen), we identified seven cases who met the following criteria: completion of therapy, residual contrast enhancing lesion, no low grade lymphoma, and follow up for at least one year. Among these, four matched the revised response criteria as proposed by Küker and et al and two of them showed an early relapse 3 and 6 months after completion of therapy. The other three showed residual contrast enhancing lesions, all located within the primary tumor region, measuring 8mm. These patients showed a progression free survival of 20+, 29 and 88+ months. Two of the patients showed spontaneous disappearance of the lesions and the other a partial involution. We conclude that categorizing patients’ responses according to these revised criteria is not predictive of their individual course after therapy. Therefore, patients with CRu should be carefully observed with serial scans. [2] References 1. Küker W, Nägele T, Thiel E, et al. Primary central nervous system lymphomas (PCNSL): MRI response criteria revised. Neurology 2005;65:1129- 1131. 2. Abrey LE, Batchelor TT, Ferreri AJM, et al. Report of an International Workshop to Standardise Baseline Evaluation and Response Criteria for Primary CNS Lymphoma. J Clin Oncol 2005;23:5034-5043. 3. Pels H, Schmidt-Wolf IGH, Glasmacher A, et al. Primary Central Nervous System Lymphoma: Results of Pilot and Phase II Study of Systemic and Intraventricular Chemotherapy With Deferred Radiotherapy. J Clin Oncol 2003;21:4489-4495. Disclosure: The authors report no conflicts of interest.
Reply from Authors 5 December 2005
W. Kuker, The Radcliffe Infirmary Woodstock Road, Oxford OX2 6HE, UK, Ulrich Herrlinger Send Correspondence to journal: Re: Reply from Authors Wilhelm.Kueker{at}orh.nhs.uk W. Kuker, et al.	We read Schlegel et al's letter with great interest and thank them for the additional data. We agree with their final statement that all patients with PCNSL should be closely monitored. However, surveillance scanning cannot be restricted to patients classified as complete response (CR) with small residual lesions but has to include patients with CR as defined by the original MacDonald criteria. These patients have also been shown to relapse early after CR. In the NOA-03 trial [4] one of 11 patients without any residual contrast enhancing lesion relapsed within the first 6 months after the completion of therapy. It is plausible that Dr. Schlegel’s patients who relapsed early after unproven CR did so at the site of the contrast-enhancing residual. It is not surprising that relapses may occur in patients with residual lesions, as in those without. The crucial point about the new classification scheme is that this is not even most frequently the case. In our treatment trial, all patients with residual contrast uptake were supposed to be treated as partial response (PR) and hence submitted to further therapy. The four patients we reported who were not receiving salvage therapy were an exception and protocol violation. We may assume that among the remaining 64 patients with residual contrast-enhancing lesions who received further therapy several were treated unnecessarily. This point is confirmed by Schlegel et al who describe three patients with even larger lesions that did not progress over a long time in spite of a lack of treatment. The suggested new criteria for modified CR may even have to be expanded if more data becomes available. As in all classifications, sensitivity has to be balanced against specificity, which in this case does seem to advocate a careful approach. Further work and the application of more sophisticated imaging modalities such as PET may be necessary to better define the presence of residual viable tumor tissue. References 4. Herrlinger U, Kuker W, Uhl M, et al. Neuro-Oncology Working Group of the German Society. NOA-03 trial of high-dose methotrexate in primary central nervous system lymphoma: final report. Ann Neurol 2005;57:843-847. Disclosure: The authors report no conflicts of interest.