Prognostic utility of (18)F-FDG PET-CT performed prior to and during primary radiotherapy for nasopharyngeal carcinoma: Index node is a useful prognostic imaging biomarker site

Peter Lin; Myo Min; Mark Lee; Lois Holloway; Dion Forstner; Victoria Bray; Wei Xuan; Andrew Chicco; Allan Fowler

doi:10.1016/j.radonc.2016.05.021

Prognostic utility of (18)F-FDG PET-CT performed prior to and during primary radiotherapy for nasopharyngeal carcinoma: Index node is a useful prognostic imaging biomarker site

Radiother Oncol. 2016 Jul;120(1):87-91. doi: 10.1016/j.radonc.2016.05.021. Epub 2016 Jun 16.

Authors

Peter Lin¹, Myo Min², Mark Lee³, Lois Holloway⁴, Dion Forstner², Victoria Bray⁵, Wei Xuan⁶, Andrew Chicco⁷, Allan Fowler⁵

Affiliations

¹ Department of Nuclear Medicine and PET, Liverpool Hospital, Australia; South Western Sydney Clinical School, University of New South Wales, Australia; University of Western Sydney, Australia. Electronic address: peter.lin@sswahs.nsw.gov.au.
² South Western Sydney Clinical School, University of New South Wales, Australia; Cancer Therapy Centre, Liverpool Hospital, Australia; Ingham Institute of Applied Medical Research, Liverpool, Australia.
³ South Western Sydney Clinical School, University of New South Wales, Australia; Cancer Therapy Centre, Liverpool Hospital, Australia.
⁴ South Western Sydney Clinical School, University of New South Wales, Australia; University of Western Sydney, Australia; Cancer Therapy Centre, Liverpool Hospital, Australia; Ingham Institute of Applied Medical Research, Liverpool, Australia.
⁵ Cancer Therapy Centre, Liverpool Hospital, Australia.
⁶ Ingham Institute of Applied Medical Research, Liverpool, Australia.
⁷ Department of Nuclear Medicine and PET, Liverpool Hospital, Australia.

PMID: 27321151
DOI: 10.1016/j.radonc.2016.05.021

Abstract

Purpose: To evaluate the prognostic value of (18)F-FDG-PET-CT performed prior to (prePET) and during the third week (iPET) of radiation therapy (RT) in nasopharyngeal carcinoma (NPC).

Materials and methods: Thirty-patients with newly diagnosed loco-regionally advanced NPC treated with radical RT underwent prePET and iPET. The median follow-up was 26months (8-66.9). The maximum-standardised-uptake-value (SUVmax), metabolic-tumour-volume (MTV) and total-lesional-glycolysis (TLG) of the primary tumour (PT), index-node (IN) (lymph node with highest TLG), total-lymph-nodes (TN) and combined primary-tumour and nodal (PTN), and their % reductions in iPET were analysed, and results were correlated with 2-year Kaplan-Meier loco-recurrence-free-survival (LRFS), regional-failure-free-survival (RFFS), distant-metastatic-failure-free-survival (DMFFS), disease-free-survival (DFS), and overall-survival (OS). Optimal-cutoffs (OC) were derived from Receiver-Operating-Characteristic curves.

Results: For LRFS, the only predictor was reduction in PT MTV by >50%: 95.2% vs. 75.0%, p=0.024. For other treatment outcomes, only nodal or PTN predicted outcomes. The IN SUVmax (pre-PET-OC=10.45g/mL and iPET-OC=8.15) and TLG (prePET-OC=90g and iPET-OC=33.4) were the best predictors of outcome: RFFS (iPET SUVmax/TLG): 100% vs. 50%, p<0.001 and 100% vs. 44%, p=0.032; DMFFS (prePET SUVmax/TLG); 100% vs. 51.9%, p=0.004 and 100% vs. 47.6%, p=0.002; DFS (prePET TLG and iPET SUVmax): 87.5% vs. 33%, p=0.045 and 78.7% vs. 20%, p=0.01; and OS (prePET TLG): 100% vs 66.3%, p=0.036.

Conclusions: We have demonstrated IN of prePET and iPET to be a feasible and potentially useful novel imaging biomarker to predict for patients with NPC who have a high risk of regional or distant metastatic failure. Future work is required to validate our findings in a well-powered, prospective study with a standardised treatment protocol, and their potential use to guide individualised therapy for NPC.

Keywords: Adaptive radiotherapy; FDG; Imaging biomarker; Nasopharyngeal carcinoma; PET CT; Positron emission tomography; Prognostic value.

MeSH terms

Adult
Aged
Biomarkers / metabolism
Carcinoma / diagnostic imaging
Carcinoma / mortality
Carcinoma / radiotherapy*
Disease-Free Survival
Female
Fluorodeoxyglucose F18*
Glycolysis
Humans
Male
Middle Aged
Nasopharyngeal Carcinoma
Nasopharyngeal Neoplasms / diagnostic imaging
Nasopharyngeal Neoplasms / mortality
Nasopharyngeal Neoplasms / radiotherapy*
Positron Emission Tomography Computed Tomography / methods*
Prognosis
Radiopharmaceuticals*

Substances

Biomarkers
Radiopharmaceuticals
Fluorodeoxyglucose F18