PURPOSE: The nodal relapse pattern of @entity5 ( @entity3852 ) with/without elective nodal radiotherapy (RT) was studied in a single institution. METHOD: A total of 51  @entity1 with @entity3852 , 33   % UICC stage  I, 14   % II, 53   % III (4  lymph node @entity3 of unknown primary) were eligible. All @entity1 had surgical staging: 23  @entity1 sentinel node biopsy (SNB), 22  @entity1 SNB followed by lymphadenectomy (LAD) and 6  @entity1  LAD. In all, 94   % of the @entity5 ( @entity5 ) were completely resected; 57   % of @entity1 received RT, 51   % of known @entity5 sites, 33   % (8/24 @entity1 ) regional RT to snN0 nodes and 68   % (17/27 @entity1 ) to pN+ nodes, mean reference dose 51.5 and 50  Gy, respectively. Mean follow-up was 6  years (range 2-14  years). RESULTS: A total of 22   % (11/51) @entity1 developed regional relapses (RR); the 5-year RR rate was 27   %. In snN0 sites (stage  I/II), relapse occurred in 5 of 14 nonirradiated vs. none of 8  irradiated sites (p   =   0.054), resulting in a 5-year RR rate of 33   % versus 0   % (p   =   0.16). The crude RR rate was lower in stage  I (12   %, 2/17 @entity1 ) than for stage  II (43   %, 3/7  @entity1 ). In stage  III (pN+), RR appeared to be less frequent in irradiated sites (18   %, 3/14  @entity1 ) compared with nonirradiated sites (33   %, 3/10 @entity1 , p   =   0.45) with 5-year RR rates of 23   % vs. 34   %, respectively. DISCUSSION: Our data suggest that adjuvant nodal RT plays a major role even if the sentinel nodes were negative. CONCLUSION: Adjuvant RT of the lymph nodes in @entity1 with stage  IIa @entity5 and RT after @entity5 is proposed and should be evaluated prospectively.

Regional nodal relapse in XXXX .

@entity5 :: ('MESH:D009369', 'Disease') :: ['primary tumors', 'LAD in stage  III tumors', 'PT', 'surgically staged Merkel cell carcinoma', 'tumors'] @entity3852 :: ('MESH:D015266', 'Disease') :: ['MCC'] @entity1 :: ('9606', 'Species') :: ['patients'] @entity3 :: ('MESH:D009362', 'Disease') :: ['metastases']
@entity5 :: (MESH:D009369,Disease) :: ['surgically staged Merkel cell carcinoma']
