Abstract 93

BACKGROUND.

Positron emission tomography (PET) with 2-[18F]fluoro-2-deoxy-D-glucose (18F-FDG) currently represents the mainstay for response assessment in HL, as defined by revised response criteria (Cheson, 2007). PET negativity is mandatory to define complete remission (CR), independently from the persistence of residual masses at computed tomography (CT scan). Nevertheless, some reports suggest a slightly worse prognosis among patients (pts) with CT scan residual masses. The aim of this study was to evaluate the unfavorable predictive value of residual CT scan masses in HL pts with PET negative at the end of treatment.

MATERIAL AND METHODS.

The present analysis was retrospectively conducted in 105 pts with negative PET at the end of first or second line treatment, at our institution, from February 2004 to February 2009. All pts had disease evaluation performed also with CT scan.

RESULTS.

Main clinical characteristics: median age 58 years, males 62, B-symptoms 25, bulky disease 41, prior radiotherapy 57. Seventy-four pts were evaluated after first line treatment program, while 31 pts after salvage therapy program. In 76 pts, residual CT scan mass (PET-/CT scan +) of at least 2.0 cm in the largest diameter was assessed. Fifty-seven had only one site residual mass, while 19 pts had more than one site. Considering the whole series, with a median follow-up of 45 months, 23 pts relapsed, nine patients died and 94 are alive without disease.

The five year disease-free survival (DSF) for PET-/CT scan- vs PET-/CT scan+ pts was 89.4% and 68.7% respectively (P=0.053). The prognostic impact of residual mass at CT scan had a correlation with the dimension of the residual itself in a continuous fashion: the larger is the mass, the lower the DFS: HR 1.03 (1.01; 1.05) p 0.007. This difference is even more pronounced when a cut-off of 4 cm in the largest diameter of the residual mass is applied: in patients with a mass diameter ≥ vs < 4 cm, DFS is 50% vs 82% respectively (HR 3.25: CI 1.5; 7.04, p 0,029 – figure 1). Among all the other prognostic factors analyzed (number of masses, first vs salvage treatment program, sex, bulky disease, B-symptoms), no correlation with DSF or overall survival (OS) emerged.

FIGURE 1
FIGURE 1.
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CONCLUSIONS.

In our study we observe a significant difference in DFS among PET negative pts with or without CT scan residual masses after therapy for HL. This difference is more significant when the residual mass is larger than 4 cm. Thus, despite PET is the main tool in respons-e definition, CT scan maintains an important role and can not yet be abandoned. The role of consolidation radiotherapy in these cases should be focused.

Disclosures:

No relevant conflicts of interest to declare.

Topics:
computed tomography, hodgkin's disease, positron-emission tomography, prognostic factors, radiation therapy, brachial plexus neuritis, complete remission, fluorodeoxyglucose f18, follow-up, glucose

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Author notes

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Asterisk with author names denotes non-ASH members.

© 2011 by The American Society of Hematology
2011
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