Virtual Library

 x 
My Library Virtual Library FAQ

Start Your Search

M. Bressel



Author of

  • +

    MO23 - Radiotherapy II: Lung Toxicity, Target Definition and Quality Assurance (ID 107)

    • Event: WCLC 2013
    • Type: Mini Oral Abstract Session
    • Track: Radiation Oncology + Radiotherapy
    • Presentations: 1
    • +

      MO23.01 - Four-dimensional Gallium-68 perfusion PET/CT scans can improve radiotherapy planning through functional avoidance of lung (ID 2490)

      10:30 - 10:35  |  Author(s): M. Bressel

      • Abstract
      • Presentation
      • Slides

      Background
      [68]Ga-macroaggregated-albumin ([68]Ga-MAA) perfusion PET/CT is a novel molecular imaging technique for the assessment of functional lung volumes. This prospective study aims to investigate the utility of four-dimensional (4D) [68]Ga-perfusion PET/CT for functional adaptation of radiation therapy (RT) planning in patients with non-small cell lung cancer (NSCLC).

      Methods
      An interim analysis was performed of a prospective clinical study of patients with NSCLC who underwent 4D-perfusion PET/CT scanning prior to curative intent RT. All patients were planned to 60Gy in 30fx with or without concurrent chemotherapy based on conventional anatomical lung volumes. Subsequently, a single nuclear medicine physician in conjunction with a single radiation oncologist contoured the functional ‘perfused’ lung using a visually adapted threshold. Functional lung was defined as lung parenchyma with Ga-MAA uptake. A second volume labeled as ‘high-perfused’ lung was created based on a visually adapted 30% max SUV threshold (figure 1). A single RT planner optimised the 3D conformal radiotherapy plan to spare the functionally ‘perfused’ and ‘high-perfused’ lung volumes respectively. Dose volumetrics were compared using mean lung dose (MLD), V5, V10, V20, V30, V40, V50 and V60 parameters. Figure 1 figure 1 - RT Plans optimised to each of the conventional, 'perfused' and 'high perfused' lung volumes.

      Results
      14 consecutive patients had RT plans adapted to functional lung volumes based on perfusion PET/CT. This patient cohort consisted of ex-smokers with pre-existing airways disease, with a mean FEV1 of 1.87L (0.83L-2.82L) and DLCO of 54% (27%-87%). The average MLD of the original treatment plans was 11.44Gy using conventional anatomical lung measurements. When considering the functional ‘perfused’ lung and ‘high perfused’ lung, the original plan produced an average MLD of 11.12Gy and 12.41Gy respectively. Plans optimized for ‘perfused’ lung only showed significant improvement of the V60 dose parameter (median 1.00Gy, p=0.04). However, plans optimized for ‘high perfused’ lung improved MLD, V30, V40, V50 and V60 (all p-values <0.05). The MLD was improved by a median of 0.86Gy, p<0.01. The largest improvement was found in the V30 parameter, with a median difference of 1.76Gy.

      Conclusion
      This is the first study of [68]Ga perfusion PET/CT for planning the treatment of lung cancer patients. RT plans adapted to ‘high perfused’ but not ‘perfused’ functional lung volumes allows for significant technical improvement of conventional RT for NSCLC patients. The clinical impact of this improvement in planning technique should be validated in the context of a prospective study measuring patient toxicity outcomes.

      Only Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login, select "Add to Cart" and proceed to checkout. If you would like to become a member of IASLC, please click here.

      Only Active Members that have purchased this event or have registered via an access code will be able to view this content. To view this presentation, please login or select "Add to Cart" and proceed to checkout.

  • +

    P1.13 - Poster Session 1 - SCLC (ID 200)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Medical Oncology
    • Presentations: 1
    • +

      P1.13-002 - Prognostic Value of 18F-fluorodeoxyglucose Uptake in Small Cell Lung Cancer Patients Treated with Concomitant Chemo-radiotherapy or Chemotherapy alone (ID 1277)

      09:30 - 09:30  |  Author(s): M. Bressel

      • Abstract

      Background
      There is some evidence that the standard uptake value (SUV) measured using 18F- fluorodeoxyglucose positron emission tomography ([18]FDG-PET) in patients with non-small cell lung cancer (NSCLC) may be prognostic for survival. Small cell lung cancer (SCLC) clinically differs from NSCLC by its rapid proliferation and is staged as either limited disease (LD) defined as disease confined to one hemithorax and the regional lymph nodes or extensive disease (ED) which is disease that has spread beyond this. There is much less information available on the potential prognostic value of the SUV obtained during [18]FDG-PET scanning in SCLC. This study thus aims to explore whether SUV can be effective in the prognostic stratification of SCLC patients with LD and ED.

      Methods
      Retrospective study of patients diagnosed with SCLC who underwent a pre-treatment 18FDG-PET scan between 1999 – 2008 at the Peter MacCallum Cancer Centre and 2004 -2011 at the Austin Hospital. Patients with LD were treated with radical concomitant chemo-radiotherapy and those with ED treated with chemotherapy alone. Maximum and mean SUVs were retrieved, and survival of patients measured. The correlation between SUV and other patients’ clinicopathological factors, including age, sex, performance status, weight loss and tumour stage (TNM) were also explored.

      Results
      Thirty-six eligible patients were identified, with a median follow-up of 14 months (range, 3-103 months). There were 23 males and 13 females. The median age was 69 years (55-84 years). Twenty patients had LD and 16 had ED. Thirteen patients had stage IV disease and 10 patients each had stage IIIA and IIIB disease (3 patients were unable to be staged according to TNM classification system). Higher TNM stage was associated with higher SUVmax (r~s~=0.37, p=0.036) but not with SUVmean (r~s~=0.30, p=0.086). There was no evidence of a significant association between clinicopathological factors with SUVmax in patients with LD and ED, except for age in patients with ED. Increasing age was associated with higher SUVmax (r~s~=0.72, p=0.002) and higher SUVmean in patients with ED (r~s~=0.81, p<0.001). SUVmax and SUVmean were not significantly associated with OS in patients with LD or ED or in the whole sample.

      Conclusion
      In patients with SCLC there was an association between higher SUVmax and higher TNM stage, as observed in patients with NSCLC. However, in this small patient cohort, we were unable to find evidence of an independent prognostic effect of SUVmax on overall survival.

  • +

    P3.08 - Poster Session 3 - Radiotherapy (ID 199)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Radiation Oncology + Radiotherapy
    • Presentations: 1
    • +

      P3.08-019 - Visual assessment of the presence of central photopenia on FDG-PET imaging in non-small cell lung cancer (NSCLC) and its prognostic influence on survival in patients treated with radiotherapy. A subset analysis of TROG 99.05. (ID 2513)

      09:30 - 09:30  |  Author(s): M. Bressel

      • Abstract

      Background
      Cavitation in NSCLC has anecdotally been associated with worse prognosis and survival. It has been postulated that rapid tumour growth and disordered angiogenesis leads to necrosis, cavitation and central hypoxia, with associated reduction in tumour radiosensitivity. This study investigated central photopenia on FDG-PET imaging (indicating reduced metabolic activity in necrotic areas) as an independent prognostic factor in patients with NSCLC treated by definitive radiotherapy.

      Methods
      Pre-treatment PET images for 172 patients (single institution, enrolled in multicentre prospective observational study TROG 99.05) with pathologically proven stage I-III NSCLC planned for definitive radiotherapy (minimum 50 Gy in 20 fractions) or chemoradiotherapy (93.4%) were independently analysed by two investigators at two time points one month apart. The presence and percent of tumour demonstrating central photopenia were scored using visual assessment. Central photopenia was defined as a non-peripheral volume within the primary tumour with an SUV <40% of the SUVmax. Survival was adjusted for known prognostic factors including performance status, T and N stage.

      Results
      Inter-observer agreement for the presence (Kappa=0.822, p<0.001) and proportion (intraclass correlation coefficient (ICC)=0.913 with 95% CI, 0.862-0.946, p<0.001) of photopenia and were good. Intra-observer reassessment showed fair agreement (Kappa=0.600, p<0.001 and ICC=0.752 with 95% CI, 0.634-0.836, p<0.001). Photopenia, present in 43% of the tumours was associated with larger tumour volumes (mean volume 197.3cm[3 ]vs 56.2cm[3 ]in solid tumours, p<0.001) and weight loss (51% of patients vs 31%, p=0.029). Median survival was shorter in the presence of photopenia but there was no significant difference in overall survival (OS) on univariate (HR=1.25, 95% CI, 0.89-1.77, p=0.200) or multivariate analysis (HR=1.14, 95% CI, 0.80-1.61, p=0.465) after adjusting for stage and performance status. Correlations of OS and the percent of photopenia were not statistically significant. Figure 1

      Conclusion
      The presence and proportion of photopenia on FDG-PET imaging can be reproducibly measured using visual analysis without requiring specialist workstation software. Central photopenia was associated with larger tumours, weight loss, and shorter median survival, but there was no statistically significant effect on overall survival after adjusting for known prognostic factors.