Rituximab or Zevalin - Efficacy Trial of Therapeutic Alternatives (RoZetta)

EFS time is defined as the time from randomization to first documented progression, death from any cause, or introduction of a new anti-lymphoma treatment (chemotherapy, radiotherapy or immunotherapy).

TTP is defined as the time from randomization to the first disease progression.

TTNLT is defined as the time from randomization to the first introduction of any new anti lymphoma regimen.

TTNCT is defined as the time from randomization to the first introduction of any new chemotherapy (cytotoxic or radioimmunotherapy). The TTNCT may be the same as the TTNLT. Participants who respond to treatment and Participants who are lost to follow-up censored at the visit on which the dosing of a new medication was evaluated.

Tumor response evaluated according to Cheson criteria at the time of randomization and at the end of the maintenance/observation, post randomization. ORR is defined as the percentage of Participants with a complete response (CR) or a partial response (PR), and compared between treatment groups. Participants with no response evaluation (for any reason) considered as not evaluable (NE).

OS is defined as the time from randomization to death from any cause. In living patients, survival time was censored on the last date participants were known to be alive.

Transformation rate at first progression, defined as the appearance of diffuse areas of large lymphoma cells within a tumor site.

Toxicity graded according to the National Cancer Institute Common Toxicity Criteria for Adverse Events version 4.0.

The FACT-G is a participant rated, 27-item compilation of general questions divided into 4 primary Quality of Life (QOL) sub-scales: physical well-being (PWB; 7-items, score range 0-28), social/family well-being (SWB; 7-items, score range 0-28), emotional well-being (EWB; 6-items, score range 0-24), and functional well-being (FWB; 7-items, score range 0-28). This tool represents the generic core questionnaire that are utilized in combination with cancer site-specific questionnaires, (FBrain, in this study) Overall score and four subscale scores with ranges and distributions that are sample-specific can be calculated.FACT-G is scored by summing the individual scale scores; higher scores indicate better quality of life. FACT-G uses 5-point rating scale ranging from (0) = Not at all; (1) = A little bit; (2) = Somewhat; (3) = Quite a bit; to (4) = Very much.The FACT-G total score is the sum of the four subscale scores (if least 80% completed) and has a possible range of 0-108 points.

EORTC-QLQ-C30 is a cancer-specific instrument with 30 questions for evaluation of new chemotherapy and provides an assessment of participant reported outcome dimensions. First 28 questions used 4-point scale (1=not at all,2=a little,3=quite a bit,4=very much) for evaluating 5 functional scales (physical,role,emotional,cognitive,social), 3 symptom scales (fatigue,nausea/vomiting,pain) \& other single items. For each item,high score represented high level of symptomatology/problem. Last 2 questions represented participant's assessment of overall health \& quality of life, coded on 7-point scale (1=very poor to 7=excellent).EORTC QLQ-C30 observed values and change from baseline for global health status (scoring of questions 29 \& 30) and 5 functional scales, 3 symptom scales and other single items (scoring of questions 1 to 28). Answers were converted into grading scale, with values between 0 and 100. High score represented a favourable outcome with a best quality of life for participant.

A cost-effectiveness analysis done that compares the efficiency (cost/effectiveness unit) of consolidation treatment with 90Y-ibritumomab tiuxetan compared to maintenance treatment with rituximab. The analysis conducted according to a health economic analysis plan independent from this clinical study protocol.