RADIATION TREATMENT OF FOLLICLE CENTER LYMPHOMA - RESULTS OF A GERMANMULTICENTER AND PROSPECTIVE-STUDY

Purpose: Follicle centre lymphoma grade I, II (REAL) or centroblastic- centrocytic lymphoma (Kiel classification) present a well defined clin ical entity from a clinical point of view. These lymphomas are not cur able by chemotherapy in early or advanced stages. They are treated by radiation therapy in early stages, but up to now the curative potency of radiotherapy has not been confirmed by prospective clinical trials. Patients and Method: Between January 1986 and August 1993 117 adults with follicle centre lymphoma were recruited from 24 institutions to e nter the multicentric prospective, not randomised clinical trial. Pati ents with histologically proven nodal follicle centre lymphoma of stag es I, II and limited III were included. They were treated by a standar dised radiotherapy regimen, in stage I by extended field and in stages II and III by total nodal irradiation. Dose per fraction was 1.8 to 2 .0 Gy, in the abdominal bath 1.5 Gy up to a total dose of 26 Gy in adj uvant situation and 36 Gy to enlarged lymphoma. Results: All patients developed a complete remission at the end of radiotherapy. Median foll ow-up is 68 months. Overall survival of all patients is 86 +/- 3% at 5 and 8 years. Stage adjusted survival at 5 and 8 years was 89% for sta ge I, 86% for stage II and 81% for III. Patients in stages I and II < 60 years had survival rates of 94% at 5 and 8 years, patients > 60 yea rs 63% (p < 0.0001). Recurrence free survival of all patients is 70% a t 5 and 60 +/- 5% at 8 years. The number of recurrences is high with 2 9% at 5 and 41% at 8 years. All recurrences were seen within 7 years. The probability of localised nodal in-field recurrences is 11% and 22% at 5 and 8 pears, respectively. Adverse prognostic factors were ident ified by multivariate analysis: age > 60 years, treatment breaks 27 da ys and dose deviations > 20% from prescribed doses. Acute side effects of extended field irradiation were moderate. Conclusions: On the basi s of these results radiotherapy is a potentially curative therapeutic approach in stages I, II and limited III of follicle centre lymphoma. The optimal technique is total lymphoid irradiation with doses of 30 G y in the adjuvant situation and 40 to 44 Gy in enlarged lymphomas. The number of local recurrences leads to the assumption, that the extensi on of radiotherapy to the total lymphoid system might reduce their fre quency.