mild-dose imrt for early-staged extranodal nasal-type nk/t-cell lymphoma with cr tumor after gelox chemotherapy

Conditions: Lymphoma,; Non-Hodgkin Lymphoma,; Extranodal NK/T-cell Lymphoma,Nasal-type,

Summary: this study is to make sure whether reduced-dose radiation treatment is sufficient to control the disease in patients with early-staged extranodal nasal-type nk/t-cell lymphoma, who have got complete remission tumor after chemotherapy in a new and more effective asparaginase-based gelox regimen

definitive radiotherapy(rt) is mainstay in combined-modality treatment for patients with early-staged extranodal nasal-type nk/t-cell lymphoma(enktl),it can be used upfront or after short courses of chemotherapy. the typical dose of rt is recommended as 50-56gy in conventional fractionations with 3 dimensional conformal rt or intensity-modulated radiation treatment(imrt). asparaginase-based chemotherapy regimens are being investigated, and primary results showed superior to previous anthracycline-based (eg. chop) chemotherapy. gelox is a new asparaginase-based chemotherapy regimen designed and published in our institute, and the rate of complete remission(cr) is well improved. we hypothesis the reduced-dose radiation treatment(imrt in 46gy) is sufficient to control the disease in patients with early-staged enktl, who have got cr after gelox chemotherapy, and to validate in this phase ii study. 1. patients: * all patients should sign a written informed consent form before enrollment, and the study should be approved by the sun yat-sen university cancer center ethics board. * baseline of patients: computed tomography (ct) scans of the chest, abdomen, and pelvis, magnetic resonance imaging studies of the head and neck, and bilateral bone marrow aspiration or biopsy. positron emission tomography-ct scans (optional). epstein-barr virus (ebv) dna blood levels, titer of ebv antibody (ea-iga, vca-iga). * recheck before and after gelox chemotherapy and imrt: epstein-barr virus (ebv) dna blood levels, titer of ebv antibody (ea-iga, vca-iga), computed tomography (ct) scans of the chest, abdomen, and pelvis, magnetic resonance imaging studies of the head and neck, positron emission tomography-ct scans (optional). 2. treatment protocol: 1. the gelox regimen consist of the following drugs: gemcitabine：1250 mg/ m2 on days 1,iv drip; oxaliplatin：85 mg/m2 on day 1, iv drip; pegaspargase: 2500 iu/m 2 daily on day 1,intramuscular. the treatment cycle is repeated every 14 days. 2. imrt is delivered using 6-8mev linear accelerator using extended involved-field intensity-modulated radiation treatment planning. the rt dose is 46.2 grays (gy) in 22 fractions, and a simultaneous-boost method is used. * we assign gross tumor volume (gtv) to 46.2gy/22f, which is delineated according to the initial gross tumor volume identified with imaging and physical examination, including the primary tumor and involved regional lymph nodes. * the high-risk clinical target volume (ctv1) is assigned to 41.8gy/22f, which is delineated including the first batch of adjacent structures around gtv, and lymph node group apt for involvement according to clinical feature of individual tumors. * the low-risk clinical target volume (ctv2) is assigned to 36.3gy/22f, which is delineated including the extrapolated structures outside of ctv1 sites, and ln groups adjacent to ctv1 ln groups.

Eligibility criteria:
inclusion criteria: * newly diagnosed enktl * age:18-75years * ann arbor stage ie,or stage iie with cervical lymph node involvement * at lease one measurable lesion * received gelox chemotherapy and got cr before radiotherapy * eastern cooperativeoncology group performance status of 0 to 2 * adequate hematologic function (eg, white blood cell ≥ 3×10e9/l,neutrophils count ≥1.5×10e9/l, and platelet count≥ 100×10e9/l),renal function (eg, serum creatinine≤1.5 mg/dl and creatinine clearance ≥50 ml minute), and hepatic function (e.g, total bilirubin≤ 2 times the upper limit of normal and aspartate and alanine transaminase levels ≤ 3 times the upper limit of normal) exclusion criteria: * mismatch the inclusion criteria, * got non-cr after gelox chemotherapy before imrt, * systematic central nervous system involvement, previous or concomitant malignancies and any coexisting medical problems that could cause poor compliance with the study protocol, * primary lesion not from the upper aerodigestive tract

Keywords: extranodal nk/t-cell lymphoma,nasal-type, radiotherapy, intensity-modulated radiation treatment, asparaginase-based chemotherapy, loco-regional control, survival