Hutchings 2005.

Study characteristics
Methods	Secondary citation(s) NA Language of publication English Study design Not reported Study centre(s) Guy’s and St. Thomas’ Hospital, London Country UK Median follow‐up time (range) 40.2 months (6‐125)
Participants	Number of included participants 85 Inclusion criteria Histologically‐confirmed HL Early interim FDG‐PET scans Exclusion criteria None Consent Not reported Recruitment period May 1993 to January 2004 Age (range, in years) 36.7 (15‐73) Ethnic group(s) Not reported Stages of disease All stages Comorbidities Not reported Therapy regimen According to departmental protocols: mainly ABVD, number of cycles not reported; additional radiotherapy depending on stage and site of HL Alternative therapy for participants without satisfactory remission during initial chemotherapy
Prognostic factor(s)	Prognostic factor(s) Interim PET Definition of prognostic factor(s) Half‐body PET scan (mid‐brain to upper thigh) Timing of prognostic factor measurement After 2 or 3 cycles of chemotherapy, within the second week of the interval between cycles or as late as possible before administration of the next cycle Method for measurement (use of specific scale and cut‐off) No specific scale indicated 2 experienced nuclear medicine physicians interpreted all scans, differences decided by consensus PET‐negative defined as no evidence of disease; PET‐positive defined as increased uptake suspicious for malignant disease; Minimal residual uptake (MRU) defined as low‐grade uptake not likely to represent malignancy Was the same definition and method for measurement used in all participants? Yes Were prognostic factor(s) assessed blinded for outcome(s), and for each other (if relevant)? Not reported
Outcome(s)	Primary outcome(s) and definition(s) Progression‐free survival (PFS), defined as the time from diagnosis to first evidence of progression or relapse, or to disease‐related death Overall survival (OS), defined as the time from diagnosis to death from any cause Secondary outcome(s) and definition(s) None Timing of outcome measurement At 2 and 5 years Was the same definition and method for measurement used in all participants? Yes Was/were outcome(s) assessed blinded for prognostic factor(s), and for each other (if relevant)? Not reported
Missing data	Participants with any missing value? No If yes, how were missing data handled? NA
Analysis	Univariable analysis: Yes Total number of participants included in univariable analysis for each outcome PFS: all OS: not reported Statistical method Kaplan‐Meier (survival curves) Log‐rank (differences between groups) Proportional hazards Cox regression analysis How was the prognostic factor treated? Binary Multivariable analysis: Yes Total number of participants included in multivariable analysis for each outcome PFS: all OS: none Statistical method Kaplan‐Meier (survival curves) Log‐rank (differences between groups) Proportional hazards Cox regression analysis How was the prognostic factor treated? Binary Number of candidate covariates 4 List of all candidate covariates Early interim PET Ann Arbor stage PET‐MRU vs. PET‐negative PET‐positive vs. PET‐negative
Risk of bias (QUIPS)	Study participation Unclear risk All eligible participants included. Clear description of participants and study characteristics. No inclusion / exclusion criteria provided. No comparison to baseline population, and no explanation of missing scans provided. Study attrition Moderate risk Loss to follow‐up (8 participants), but reasons not provided. Prognostic factor measurement Low risk Adequate description. PET results separated into negative, positive and low MRU, which sometimes was considered negative (clearly stated in these cases). No clear cut‐off in numbers. Outcome: Overall survival Outcome measurement Low risk Clear definition. Outcome measured the same way for all participants. Participants lost to follow‐up were still included in analysis. 'Other prognostic factors (covariates)' High risk Disease stage not accounted for. Statistical analysis and reporting Low risk Statistical method in univariable analysis appropriate for the data. Outcome: Progression‐free survival Outcome measurement Low risk Clear definition. Outcome measured the same way for all participants. Participants lost to follow‐up were still included in analysis. 'Other prognostic factors (covariates)' Low risk Adjusted for disease stage. Statistical analysis and reporting Low risk Statistical method appropriate for the data. Outcome: Adverse events Not reported
Notes	Conflict of interest Not reported Funding Not reported