Treatment outcome of patients with synchronous oligometastatic non-small cell lung cancer in the immunotherapy era: Analysis of a real-life intention-to-treat population

The standard first-line treatment for non-oncogene driven metastatic non-small cell lung cancer (NSCLC) is an immune checkpoint inhibitor (ICI) based strategy. Although guidelines increasingly advise adding local radical treatment (LRT) to patients with synchronous oligometastatic (sOMD) NSCLC responding to systemic therapy, this recommendation is based on the studies without ICI. Furthermore, the majority of published oligometastatic studies were not on an intention-to-treat basis, resulting in selection bias. Moreover, staging Positron Emission Tomography-Computed Tomography (PET-CT) and brain imaging were often not mandatory and definitions of oligometastatic were heterogeneous. Therefore, this study focused on a single centre retrospective series, including all adequately staged patients with sOMD NSCLC according to the European Organisation for Research and Treatment of Cancer definition (maximum of 5 metastases in 3 organs) that were treated with induction (chemo)-ICI and compared outcomes to those treated with chemotherapy only, with and without LRT. The primary end-points were median progression-free survival (PFS) and overall survival (OS) for patients treated with induction (chemo)-ICI versus chemotherapy. Out of 68 included patients, 38 (56%) eventually received LRT. With a median follow-up of 26.7 months, the median PFS was 19.0 months for (chemo)-ICI (n = 18) versus 6.8 for chemotherapy-only (n = 50) (HR 0.5, p = 0.03), the median OS was 19.3 versus 15.7 months, respectively (HR 0.8, p = 0.4). In patients having received LRT, median PFS was 19.0 months for (chemo)-ICI versus 8.3 for chemotherapy-only (HR 0.6, p = 0.2). In conclusion, an ICI-based systemic treatment is feasible and may result in superior survival outcomes. This should be investigated in prospective trials. Strategies to improve response rates to systemic treatment are also needed.

Early Loss of Fat Mass During Chemoradiotherapy Predicts Overall Survival in Locally Advanced Squamous Cell Carcinoma of the Lung, but Not in Locally Advanced Squamous Cell Carcinoma of the Head and Neck

Background: Cancer cachexia is highly prevalent in advanced non-small cell lung cancer (NSCLC) and locally advanced head and neck squamous cell carcinoma (LAHNSCC), and compromises treatment tolerance and overall survival (OS). NSCLC and LAHNSCC patients share similar risk factors, and receive comparable anti-cancer treatment regimens. The aim of this study was to determine the predictive value of body composition assessed by bioelectrical impedance analysis (BIA) and handgrip strength (HGS) (baseline and early changes during therapy) on OS in NSCLC and LAHNSCC patients treated with platinum-based chemoradiotherapy (CRT) or cetuximab-based bioradiotherapy (BRT). To elucidate potential underlying determinants of early changes in body composition and HGS, specific (fat and fat free) mass loss patterns of squamous NSCLC (sNSCLC) were compared to human papilloma virus negative (HPV–) LAHNSCC patients treated with CRT.

Methods: Between 2013 and 2016, BIA and HGS were performed at baseline and after 3 weeks of CRT/BRT in LAHNSCC and NSCLC patients treated with curative intent.

Results: Two hundred thirty-three patients were included for baseline measurements. Fat free mass index (FFMI) and HGS<10th percentile of reference values at baseline were both prognostic for poor OS in NSCLC and LAHNSCC [HR 1.64 [95%CI 1.13–2.39], p = 0.01 and HR 2.30 [95%CI 1.33–3.97], p = 0.003, respectively], independent of Charlson Comorbidity Index, cancer site, and gross tumor volume. Early fat mass (FM) loss during CRT was predictive for poor OS in sNSCLC (n = 64) [HR 3.80 [95%CI 1.79–8.06] p ≤ 0.001] but not in HPV– LAHNSCC (n = 61). In patients with significant weight loss (>2%) in the first 3 weeks of CRT (sNSCLC n = 24, HPV– LAHNSCC n = 23), the FM change was −1.4 ± 14.5% and −8.7 ± 9.0% in sNSCLC and HPV– LAHNSCC patients, respectively (p < 0.05). Fat fee mass change was −5.6 ± 6.3% and −4.0 ± 4.3% for sNSCLC and HPV– LAHNSCC, respectively (p = 0.31).

Conclusion: FFMI and HGS<10th percentile at baseline are independent prognostic factors for poor OS in NSCLC and LAHNSCC patients treated with CRT/BRT. The specific composition of mass loss during first 3 weeks of CRT significantly differs between sNSCLC and HPV– LAHNSCC patients. Early FM loss was prognostic in sNSCLC only.

[Treatment of patients with stage III non-small cell lung cancer: concurrent high-dose chemotherapy and radiotherapy]

The treatment of patients with locally advanced non-small cell lung cancer (stage III) has changed significantly in the past few years. Patients with a non-resectable stage IIIA/B tumour are given combined treatment consisting ofchemotherapy and radiotherapy. These can be administered sequentially or concurrently. It has been shown recently that concurrent chemoradiotherapy gives a survival advantage in comparison with sequential chemoradiotherapy. Cisplatin and etoposide are usually the drugs of choice for chemotherapy in patients with stage III cancer. A biologically effective dose of radiotherapy equivalent to 60-66 Gy, over a maximum of 6.5 weeks, should be given. Surgery is possible for a selected group of patients, provided a complete objective mediastinal response has been achieved after chemoradiotherapy and a complete resection appears to be technically feasible. It is recommended to apply this treatment in a research setting. High-dose concurrent chemoradiotherapy is advised as the standard treatment for stage III non-small cell lung cancer in patients in good physical condition.

Phased attenuation correction in respiration correlated computed tomography/positron emitted tomography

The motion of lung tumors with respiration causes difficulties in the imaging with computed tomography (CT) and positronemitted tomography (PET). Since an accurate knowledge of the position of the tumor and the surrounding tissues is needed for radiation treatment planning, it is important to improve CT/PET image acquisition. The purpose of this study was to evaluate the potential to improve image acquisition using phased attenuation correction in respiration correlated CT/PET, where data of both modalities were binned retrospectively. Respiration correlated scans were made on a Siemens Biograph Sensation 16 CT/PET scanner which was modified to make a low pitch CT scan and list mode PET scan possible. A lollipop phantom was used in the experiments. The sphere with a diameter of 3.1 cm was filled with approximately 20 MBq 18F-FDG. Three longitudinal movement amplitudes were tested: 2.5, 3.9, and 4.8 cm. After collection of the raw CT data, list mode PET data, and the respiratory signal CT/PET images were binned to ten phases with the help of in-house-built software. Each PET phase was corrected for attenuation with CT data of the corresponding phase. For comparison, the attenuation correction was also performed with nonrespiration correlated (non-RC) CT data. The volume and the amplitude of the movement were calculated for every phaseof both the CT and PET data (with phased attenuation correction). Maximum and average activity concentrations were compared between the phased and nonphased attenuation corrected PET. With a standard non-RC CT/PET scan, the volume was underestimated by as much as 46% in CT and the PET volume was overestimated to 370%. The volumes found with RC-CT/PET scanning had average deviations of 1.9% (+/- 4.8%) and 1.5% (+/- 3.4%) from the actual volume, for the CT and PET volumes, respectively. Evaluation of the maximum activity concentration showed a clear displacement in the images with non-RC attenuation correction, and activity values were on average14% (+/- 12%) lower than with phased attenuation correction. The standard deviation of the maximum activity values found in the different phases was a factor of 10 smaller when phased attenuation correction was applied. In this phantom study, we have shown that a combination of respiration correlated CT/PET scanning with application of phased attenuation correction can improve the imaging of moving objects and can lead to improved volume estimation and a more precise localization and quantification of the activity.