Imaging-based target volume reduction in chemoradiotherapy for locally advanced non-small-cell lung cancer (PET-Plan): a multicentre, open-label, randomised, controlled trial

Feasibility of omitting the clinical target volume under PET-CT guidance in unresectable stage III non-small-cell lung cancer: A phase II clinical trial

BACKGROUND

This clinical trial aims at investigate the feasibility of CTV-omitted, positron-emission tomography computed tomography (PET-CT) combined with intensity-modulated radiation therapy (IMRT) for unresectable stage III NSCLC.

METHODS AND MATERIALS

This was a single-center, phase II clinical trial initiated in July 2016. Patients with unresectable stage III NSCLC undergoing routine IMRT were randomly enrolled into the study group (CTV-omitted under PET-CT guidance) and the control group (CTV-delineated). Patients received platinum-based dual-drug concurrent chemoradio therapy. In the study group, the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions; in the control group, the PCTV dose was 54 Gy given in 30 daily 1.8 Gy fractions, and the PGTV dose was 60 Gy given in 30 daily 2 Gy fractions. The primary endpoint was the incidence of radiation respiratory events or esophagitis with grade 3 or higher. The secondary endpoints included objective response rate (ORR), locate control rate, progression-free survival (PFS), failure pattern and overall survival (OS).

RESULTS

A total of 90 patients were enrolled between July 2016 and March 2019. The incidence of radiation respiratory events or esophagitis with grade 3 or higher was 11.1 % in the study group, significantly lower than the rate of 28.9 % in the control group (P = 0.035), basically due to the reduced irradiated volumes of the lungs and esophagus in the study group. The median PFS was 9.0 months versus 10.0 months (P = 0.597), and the median OS 31.0 months versus 26.0 months (P = 0.489) in the study group and the control group, respectively. The failure pattern was not significantly different between the two groups (P = 0.826).

CONCLUSION

Omitting the CTV under PET-CT guidance has high feasibility to reduce severe radiation associated toxicity in IMRT for unresectable stage III NSCLC, without compromising the efficacy.

Clinical use of positron emission tomography for radiotherapy planning - Medical physics considerations

PET/CT imaging plays an increasing role in radiotherapy treatment planning. The aim of this article was to identify the major use cases and technical as well as medical physics challenges during integration of these data into treatment planning. Dedicated aspects, such as (i) PET/CT-based radiotherapy simulation, (ii) PET-based target volume delineation, (iii) functional avoidance to optimized organ-at-risk sparing and (iv) functionally adapted individualized radiotherapy are discussed in this article. Furthermore, medical physics aspects to be taken into account are summarized and presented in form of check-lists.

High-risk patients with locally advanced non-small cell lung cancer treated with stereotactic body radiation therapy to the peripheral primary combined with conventionally fractionated volumetric arc therapy to the mediastinal lymph nodes

Introduction

A very narrow therapeutic window exists when delivering curative chemoradiotherapy for inoperable locally advanced non-small cell lung cancer (NSCLC), particularly when large distances exist between areas of gross disease in the thorax. In the present study, we hypothesize that a novel technique of stereotactic body radiation therapy (SBRT) to the primary tumor in combination with volumetric arc therapy (VMAT) to the mediastinal lymph nodes (MLN) is a suitable approach for high-risk patients with large volume geographically distant locally advanced NSCLC.

Patients and methods

In this single institutional review, we identified high-risk patients treated between 2014 and 2017 with SBRT to the parenchymal lung primary as well as VMAT to the involved MLN using conventional fractionation. Dosimetrically, comparative plans utilizing VMAT conventionally fractionated delivered to both the primary and MLN were analyzed. Clinically, toxicity (CTCAE version 5.0) and oncologic outcomes were analyzed in detail.

Results

A total of 21 patients were identified, 86% (n=18) of which received chemotherapy as a portion of their treatment. As treatment phase was between 2014 and 2017, none of the patients received consolidation immunotherapy. Target volume (PTV) dose coverage (99 vs. 87%) and CTV volume (307 vs. 441 ml) were significantly improved with SBRT+MLN vs. for VMAT alone (p<0.0001). Moreover, low-dose lung (median V5Gy [%]: 71 vs. 77, p<0.0001), heart (median V5Gy [%]: 41 vs. 49, p<0.0001) and esophagus (median V30Gy [%]: 54 vs. 55, p=0.03) dose exposure were all significantly reduced with SBRT+MLN. In contrast, there was no difference observed in high-dose exposure of lungs, heart, and spinal cord. Following SBRT+MLN treatment, we identified only one case of high-grade pneumonitis. As expected, we observed a higher rate of esophagitis with a total of seven patients experience grade 2+ toxicity. Overall, there were no grade 4+ toxicities identified. After a median 3 years follow up, disease progression was observed in 70% of patients irradiated using SBRT+MLN, but never in the spared 'bridging' tissue between pulmonary SBRT and mediastinal VMAT.

Conclusion

For high risk patients, SBRT+MLN is dosimetrically feasible and can provide an alternative to dose reductions necessitated by otherwise very large target volumes.

Cardiac Function Modifies the Impact of Heart Base Dose on Survival: A Voxel-Wise Analysis of Patients With Lung Cancer From the PET-Plan Trial

INTRODUCTION

Heart dose has emerged as an independent predictor of overall survival in patients with NSCLC treated with radiotherapy. Several studies have identified the base of the heart as a region of enhanced dose sensitivity and a potential target for cardiac sparing. We present a dosimetric analysis of overall survival in the multicenter, randomized PET-Plan trial (NCT00697333) and for the first time include left ventricular ejection fraction (EF) at baseline as a metric of cardiac function.

METHODS

A total of 205 patients with inoperable stage II or III NSCLC treated with 60 to 72 Gy in 2 Gy fractions were included in this study. A voxel-wise image-based data mining methodology was used to identify anatomical regions where higher dose was significantly associated with worse overall survival. Univariable and multivariable Cox proportional hazards models tested the association of survival with dose to the identified region, established prognostic factors, and baseline cardiac function.

RESULTS

A total of 172 patients remained after processing and censoring for follow-up. At 2-years posttreatment, a highly significant region was identified within the base of the heart (p < 0.005), centered on the origin of the left coronary artery and the region of the atrioventricular node. In multivariable analysis, the number of positron emission tomography-positive nodes (p = 0.02, hazard ratio = 1.13, 95% confidence interval: 1.02-1.25) and mean dose to the cardiac subregion (p = 0.02, hazard ratio = 1.11 Gy-1, 95% confidence interval: 1.02-1.21) were significantly associated with overall survival. There was a significant interaction between EF and region dose (p = 0.04) for survival, with contrast plots revealing a larger effect of region dose on survival in patients with lower EF values.

CONCLUSIONS

This work validates previous image-based data mining studies by revealing a strong association between dose to the base of the heart and overall survival. For the first time, an interaction between baseline cardiac health and heart base dose was identified, potentially suggesting preexisting cardiac dysfunction exacerbates the impact of heart dose on survival.

Survival effect of pretreatment FDG-PET-CT on nasopharyngeal cancer

BACKGROUND/PURPOSE

Accurate staging is the first step for optimal treatment selection in patients with nasopharyngeal carcinoma (NPC). In this propensity-score-matched, population-based cohort study, we investigated the survival effects of pretreatment 8-fluorodeoxyglucose positron emission tomography-computed tomography (¹⁸FDG-PET-CT) on patients with NPC.

METHODS

We included patients with stage I-IVA NPC receiving radiotherapy or concurrent chemoradiotherapy and categorized them into two 1:1 propensity score-matched groups according to whether or not they underwent pretreatment ¹⁸FDG-PET-CT and compared their outcomes.

RESULTS

Of the 10,756 patients, propensity score matching yielded 4366 patients in each group. According to multivariable Cox regression analyses, the most prominent correlation between pretreatment ¹⁸FDG-PET-CT and all-cause death was observed in patients with stage II NPC (adjusted hazard ratio [aHR], 0.77; 95% confidence interval [CI], 0.60-0.90; P = .0433), followed by patients with stage III NPC (aHR, 0.81; 95% CI, 0.69-0.94; P = .0071) and patients with stage IVA NPC (aHR, 0.88; 95% CI, 0.79-0.97; P = .0091). This association was not significant in patients with stage I NPC (aHR, 1.20; 95% CI, 0.75-1.93; P = .4426).

CONCLUSION

Pretreatment ¹⁸FDG-PET-CT is associated with longer survival in patients with clinical stage II-IVA NPC but not in stage I NPC.

The treatment in patients with unresectable locally advanced non-small cell lung cancer: Explorations on hot issues

The treatment efficacy for patients with unresectable, locally advanced non-small-cell lung cancer (LA-NSCLC) stagnated for a long time until the advent of immunotherapy. Immune checkpoint inhibitors, particularly programmed cell death protein 1/programmed death-ligand 1 inhibitors, have thrived, reshaping the treatment landscape for patients with lung cancer. Based on the results of the PACIFIC trial, concurrent chemoradiotherapy followed by durvalumab has become the standard of care for patients with unresectable LA-NSCLC; however, numerous issues are yet to be resolved. Currently, several clinical trials are exploring an optimal treatment paradigm, and we have summarized them for comparison to eliminate barriers. In addition, we discuss better predictive biomarkers, therapeutic options for specific populations, and other challenges to identify directions for future research design.

Metabolic targeting, immunotherapy and radiation in locally advanced non-small cell lung cancer: Where do we go from here?

In the US, there are ~250,000 new lung cancer diagnoses and ~130,000 deaths per year, and worldwide there are an estimated 1.6 million deaths per year from this deadly disease. Lung cancer is the most common cause of cancer death worldwide, and it accounts for roughly a quarter of all cancer deaths in the US. Non-small cell lung cancer (NSCLC) represents 80-85% of these cases. Due to an enormous tobacco cessation effort, NSCLC rates in the US are decreasing, and the implementation of lung cancer screening guidelines and other programs have resulted in a higher percentage of patients presenting with potentially curable locoregional disease, instead of distant disease. Exciting developments in molecular targeted therapy and immunotherapy have resulted in dramatic improvement in patients' survival, in combination with new surgical, pathological, radiographical, and radiation techniques. Concurrent platinum-based doublet chemoradiation therapy followed by immunotherapy has set the benchmark for survival in these patients. However, despite these advances, ~50% of patients diagnosed with locally advanced NSCLC (LA-NSCLC) survive long-term. In patients with local and/or locoregional disease, chemoradiation is a critical component of curative therapy. However, there remains a significant clinical gap in improving the efficacy of this combined therapy, and the development of non-overlapping treatment approaches to improve treatment outcomes is needed. One potential promising avenue of research is targeting cancer metabolism. In this review, we will initially provide a brief general overview of tumor metabolism as it relates to therapeutic targeting. We will then focus on the intersection of metabolism on both oxidative stress and anti-tumor immunity. This will be followed by discussion of both tumor- and patient-specific opportunities for metabolic targeting in NSCLC. We will then conclude with a discussion of additional agents currently in development that may be advantageous to combine with chemo-immuno-radiation in NSCLC.

PET/CT for Target Delineation of Lung Cancer Before Radiation Therapy

In clinical routine of patients suffering from lung cancer, radiotherapy/radiation oncology represents one of the therapeutic hallmarks in the multimodal treatment besides or in combination with other local treatments such as surgery, but also systemic treatments such as chemotherapy, tyrosine kinase, and immune check-point inhibitors. Conventional morphological imagings such as CT or MR are commonly used for staging, response assessment, but also for radiotherapy planning. However, advanced imaging techniques such as PET do continuously get increasing access to clinical routine overcoming limitations of standard imaging techniques by visualizing and quantifying molecular processes such as glucose metabolism, which is also of relevance for radiotherapy planning. This review article summarizes the current place of radiotherapy within the treatment regimens of patients with lung cancer and elucidates current concepts of standard morphological imaging for staging and radiotherapy planning. Moreover, the place of PET-based radiotherapy planning in a clinical context is presented and current methodological/technical advances that do comprise a potential role for radiotherapy planning in lung cancer patients are discussed.

Affinity probes based on small-molecule inhibitors for tumor imaging

Methods for molecular imaging of target areas, including optical imaging, radionuclide imaging, magnetic resonance imaging and other imaging technologies, are helpful for the early diagnosis and precise treatment of cancers. In addition to cancer management, small-molecule inhibitors are also used for developing cancer target probes since they act as the tight-binding ligands of overexpressed proteins in cancer cells. This review aims to summarize the structural designs of affinity probes based on small-molecule inhibitors from the aspects of the inhibitor, linker, dye and radionuclide, and discusses the influence of the modification of these structures on affinity and pharmacokinetics. We also present examples of inhibitor affinity probes in clinical applications, and these summaries will provide insights for future research and clinical translations.

Prediction of malignant lymph nodes in NSCLC by machine-learning classifiers using EBUS-TBNA and PET/CT

Accurate determination of lymph-node (LN) metastases is a prerequisite for high precision radiotherapy. The primary aim is to characterise the performance of PET/CT-based machine-learning classifiers to predict LN-involvement by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in stage-III NSCLC. Prediction models for LN-positivity based on [¹⁸F]FDG-PET/CT features were built using logistic regression and machine-learning models random forest (RF) and multilayer perceptron neural network (MLP) for stage-III NSCLC before radiochemotherapy. A total of 675 LN-stations were sampled in 180 patients. The logistic and RF models identified SUV_max, the short-axis LN-diameter and the echelon of the considered LN among the most important parameters for EBUS-positivity. Adjusting the sensitivity of machine-learning classifiers to that of the expert-rater of 94.5%, MLP (P = 0.0061) and RF models (P = 0.038) showed lower misclassification rates (MCR) than the standard-report, weighting false positives and false negatives equally. Increasing the sensitivity of classifiers from 94.5 to 99.3% resulted in increase of MCR from 13.3/14.5 to 29.8/34.2% for MLP/RF, respectively. PET/CT-based machine-learning classifiers can achieve a high sensitivity (94.5%) to detect EBUS-positive LNs at a low misclassification rate. As the specificity decreases rapidly above that level, a combined test of a PET/CT-based MLP/RF classifier and EBUS-TBNA is recommended for radiation target volume definition.

Thorax radiotherapy using 18F-positron emission tomography/computed tomography-guided precision radiotherapy is a prognostic factor for survival in patients with extracranial oligometastatic non-small cell lung cancer:A two-center propensity score-matched analysis

Background

This retrospective study compared positron emission tomography (PET)/computed tomography (CT) and CT in the treatment of extracranial oligometastatic non-small-cell lung cancer (NSCLC) and explored the impact of thorax radiotherapy (TRT) on patient survival.

Methods

We reviewed the medical records of Chinese patients with stage IV extracranial oligometastatic NSCLC who underwent PET/CT or CT at two centers. Propensity score matching (PSM) was used to control differences in patient characteristics between the maintenance chemotherapy alone and TRT plus maintenance chemotherapy groups.

Results

We analyzed 192 eligible patients. The median survival time was better in patients who received PET/CT than in those who only received CT (n = 192, 16 months vs. 6 months, p<0.001). Subgroup analysis showed the median survival time was significantly longer in the TRT plus maintenance group than in the chemotherapy alone group in patients who underwent PET/CT examinations (n = 94, 25 months vs. 11 months, p<0.001). However, there was no statistical difference in survival between both groups in patients who underwent CT examinations (n = 98, 8 months vs. 5 months, p = 0.180). A multifactorial analysis revealed a more favorable prognosis in patients who underwent PET/CT evaluation (HR: 0.343, 95% CI: 0.250-0.471, p <0.001) and TRT (HR: 0.624, 95% CI: 0.464-0.840, p = 0.002), than in those who did not. PSM was consistent with these results.

Conclusions

PET/CT-guided TRT is associated with improved clinical outcomes in patients with stage IV extracranial oligometastatic NSCLC.

[What dose escalation in the treatment of locally advanced non-small cell lung cancer?]

Despite significant therapeutic advances in the treatment of locally advanced inoperable non-small cell lung cancer (NSCLC), notably through adjuvant immunotherapy, the rate of therapeutic failure remains high. The use of positron emission tomography with fluorodeoxyglucose (FDG-PET), respiratory motion and intensity modulated radiotherapy (IMRT) have led to therapeutic improvements with reduced toxicity and better local control. The optimal dose to be delivered remains unknown due to discordant results of studies for almost 20 years and the way to define the area to benefit from a dose increase (whole volume, subvolume defined by pre- or per-radiotherapy PET).

[Radiation dose intensification for glioblastoma]

Glioblastoma is the most common brain tumor in adults; its treatment includes surgical excision or biopsy followed by radio-chemotherapy. Even if radiotherapy increases the survival of all patients regardless of their age or their general condition, there are always sources of radioresistance, where relapses occur and therefore treatment fails. Indeed, these foci result in a local relapse, which is observed in 95% of cases in the irradiation fields. We will describe here the current approaches to overcome this radioresistance by dose escalation, without or with guidance by metabolic and functional imaging (dose-painting). We will detail several prospective trials including the French phase III trial, SPECTRO-GLIO, randomizing the use of an integrated boost guided by spectrometric magnetic resonance imaging and similar trials developed across the Atlantic. We will also discuss approaches using different PET markers as well as diffusion or perfusion magnetic resonance imaging.

[68Ga]FAPI-PET/CT for radiation therapy planning in biliary tract, pancreatic ductal adeno-, and adenoidcystic carcinomas

Biliary-tract-carcinomas (BTC), pancreatic-ductal-adenocarcinomas (PDAC) and adenoidcystic-carcinomas (AC) have in common that they are traditionally treated with large clinical-target-volumes (CTV). The aim of this study is to examine the impact of pretreatment-[⁶⁸Ga]FAPI-PET/CT on target-volume-definition and posttreatment-[⁶⁸Ga]FAPI-PET/CT-response-assessment for BTC-, PDAC- and AC-patients referred to radiation-therapy. All consecutive BTC-, PDAC-, and AC-patients who received pretreatment-[⁶⁸Ga]FAPI-PET/CT±[¹⁸F]FDG-PET/CT were included from 01.01.2020 to 01.03.2022. MTV and SUV_max were separately generated based on [⁶⁸Ga]FAPI- and [¹⁸F]FDG-PET/CT-images. A [⁶⁸Ga]FAPI- and [¹⁸F]FDG-based-CTV was defined. Treatment-plans were compared. Treatment-response was reassessed by a second [⁶⁸Ga]FAPI-PET/CT and [¹⁸F]FDG-PET/CT after treatment-completion. Intermodality comparison of lesion-to-background-ratios [SUV_{max_lesion}/SUV_{mean_background}] for individual timepoints t₁ and t₂ revealed significant higher values for [⁶⁸Ga]FAPI compared to [¹⁸F]FDG (t₁, p = 0.008; t₂, p = 0.005). Intermodality comparison of radiation-therapy-plans showed that [⁶⁸Ga]FAPI-based planning resulted in D100% = 97.2% and V95% = 98.8% for the [¹⁸F]FDG-MTV. [¹⁸F]FDG-based-planning resulted in D100% = 35.9% and V95% = 78.1% for [⁶⁸Ga]FAPI-MTV. [¹⁸F]FDG-based-planning resulted only in 2 patients in V95% > 95% for [⁶⁸Ga]FAPI-MTV, and in 1 patient in D100% > 97% for [⁶⁸Ga]FAPI-MTV. GTV-coverage in terms of V95% was 76.4% by [¹⁸F]FDG-based-planning and 99.5% by [⁶⁸Ga]FAPI-based-planning. Pretreatment [⁶⁸Ga]FAPI-PET/CT enhances radiation-treatment-planning in this particular group of patients. While perilesional and tumoral follow-up [¹⁸F]FDG-uptake behaved uniformly, perilesional and tumoral reaction may differ in follow-up [⁶⁸Ga]FAPI-imaging. Complementary [⁶⁸Ga]FAPI- and [¹⁸F]FDG-imaging enhance treatment-response-assessment.

Systematic endoscopic staging of mediastinum to determine impact on radiotherapy for locally advanced lung cancer (SEISMIC): protocol for a prospective single arm multicentre interventional study

Background

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is established as the preferred method of mediastinal lymph node (LN) staging in non-small cell lung cancer (NSCLC). Selective (targeted) LN sampling is most commonly performed however studies in early stage NSCLC and locally advanced NSCLC confirm systematic EBUS-TBNA evaluation improves accuracy of mediastinal staging. This study aims to establish the rate of detection of positron emission tomography (PET)-occult LN metastases following systematic LN staging by EBUS-TBNA, and to determine the utility of systematic mediastinal staging for accurate delineation of radiation treatment fields in patients with locally advanced NSCLC.

Methods

Consecutive patients undergoing EBUS-TBNA for diagnosis/staging of locally advanced NSCLC will be enrolled in this international multi-centre single arm study. Systematic mediastinal LN evaluation will be performed, with all LN exceeding 6 mm to be sampled by TBNA. Where feasible, endoscopic ultrasound staging (EUS-B) may also be performed. Results of minimally invasive staging will be compared to FDG-PET. The primary end-point is proportion of patients in whom systematic LN staging identified PET-occult NSCLC metastases. Secondary outcome measures include (i) rate of nodal upstaging, (ii) false positive rate of PET for mediastinal LN assessment, (iii) analysis of clinicoradiologic risk factors for presence of PET-occult LN metastases, (iv) impact of systematic LN staging in patients with discrepant findings on PET and EBUS-TBNA on target coverage and dose to organs at risk (OAR) in patients undergoing radiotherapy.

Discussion

With specificity of PET of 90%, guidelines recommend tissue confirmation of positive mediastinal LN to ensure potentially early stage patients are not erroneously denied potentially curative resection. However, while confirmation of pathologic LN is routinely sought, the exact extent of mediastinal LN involvement in NSCLC in patient with Stage III NSCLC is rarely established. Studies examining systematic LN staging in early stage NSCLC report a significant discordance between PET and EBUS-TBNA. In patients with locally advanced disease this has significant implications for radiation field planning, with risk of geographic miss in the event of PET-occult mediastinal LN metastases. The SEISMIC study will examine both diagnostic outcomes following systematic LN staging with EBUS-TBNA, and impact on radiation treatment planning.

Trial registration

ACTRN12617000333314, ANZCTR, Registered on 3 March 2017.

Effectiveness of durvalumab consolidation in stage III non-small-cell lung cancer: focus on treatment selection and prognostic factors

The pivotal PACIFIC trial defined durvalumab consolidation as the new standard of care in patients with stage III non-small-cell lung cancer treated with definitive radiochemotherapy. The authors characterized the durvalumab effect after induction chemotherapy according to the ESPATUE trial and definitive radiochemotherapy. All consecutive patients with stage III non-small-cell lung cancer receiving definitive radiochemotherapy between January 2017 and February 2020 were included. Primary end points were progression-free survival and overall survival. Altogether, 160 patients (75 PD-L1-positive, 62 PD-L1-negative, 23 unknown) received definitive radiochemotherapy, 146 (91%) of whom received prior induction chemotherapy. Durvalumab consolidation showed high effectiveness overall and in the good-risk group according to the PACIFIC trial (log-rank test: p < 0.005). Hazard ratios for progression-free survival and overall survival were at the lower limits of those in the PACIFIC trial. These results were robust to adjustment for potential confounders by propensity score weighting. Eastern Cooperative Oncology Group (ECOG) performance status was the most important pretreatment prognostic factor.

Locally advanced NSCLC: a plea for sparing the ipsilateral normal lung-prospective, clinical trial with DART-bid (dose-differentiated accelerated radiation therapy, 1.8 Gy twice daily) by VMAT

Background

In radiation treatment of locally advanced non-small cell lung cancer (LA-NSCLC), ‘margins’ from internal target volumes to planning target volumes in the range of 12 to 23 mm are reported, and avoiding exposure of the contralateral lung is common practice. We investigated prospectively an approach with tight margins (7 mm) and maximal sparing of the ipsilateral normal lung. Mature results for the first endpoint (pneumonitis) and further toxicities are reported.

Methods

Primary tumors were treated by VMAT with 73.8–90.0 Gy in positive correlation to tumor volumes, nodes with 61.2 Gy, a restricted volume of nodes electively with 45 Gy. Fractional doses of 1.8 Gy bid, interval 8 h. Before radiotherapy, two cycles platin-based chemotherapy were given. 12 patients finished maintenance therapy with Durvalumab. Median follow up time for all patients is 19.4 months, for patients alive 27.0 months (3.4–66.5 months).

Results

100 consecutive, unselected patients with LA-NSCLC in stages II through IVA were enrolled (UICC/AJCC, 8th edition). No acute grade 4/5 toxicity occurred. Pneumonitis grade 2 and 3 was observed in 12% and 2% of patients, respectively; lowering the risk of pneumonitis grade ≥ 2 in comparison to the largest study in the literature investigating pneumonitis in LA-NSCLC, is significant (p < 0.0006). Acute esophageal toxicity grade 1, 2 and 3 occurred in 12%, 57% and 3% of patients, respectively. Two patients showed late bronchial stricture/atelectasis grade 2. In two patients with lethal pulmonary haemorrhages a treatment correlation cannot be excluded. Median overall survival for all stage III patients, and for those with ‘RTOG 0617 inclusion criteria’ is 46.6 and 50.0 months, respectively.

Conclusions

Overall toxicity is low. In comparison to results in the literature, maximal sparing the ipsilateral normal lung lowers the risk for pneumonitis significantly.

Trial registration

Ethics committee of Vorarlberg, Austria; EK-0.04-105, Registered 04/09/2017—Retrospectively registered. http://www.ethikkommission-vorarlberg.at

Practice changing data and emerging concepts from recent radiation therapy randomised clinical trials

INTRODUCTION

Oncology treatments are constantly and rapidly evolving. We aimed at highlighting the latest radiation therapy practice changing trials and emerging concepts, through an overview of recent randomised clinical trials (RCTs).

MATERIALS AND METHODS

Requests were performed in the Medline database to identify all publications reporting radiation therapy RCTs from 2018 to 2021.

RESULTS

Recent RCTs sustained the role of newer combinatorial strategies through radioimmunotherapy for early stage or metastatic lung cancer, newer pro-apoptotic agents (e.g. debio 1143 in locoregionally advanced head and neck squamous cell carcinoma) or nanoparticles (e.g. NBTXR3 in locally advanced soft-tissue sarcoma). High-tech radiotherapy allows intensifying treatments and gaining ground in some indications through the development of stereotactic body radiotherapy for example. First randomised evidence on personalised radiation therapy through imaging-based (¹⁸FDG positron emission tomography-computed tomography for lung cancer or early stage unfavourable Hodgkin lymphoma, PMSA positron emission tomography-computed tomography or magnetic resonance imaging for high-risk prostate cancer) or biological biomarkers (PSA for prostate cancer, HPV for head and neck cancer, etc) were conducted to more tailored treatments, with more favourable outcomes. Patients' quality of life and satisfaction appeared to be increasing aims. RCTs have validated (ultra)hypofractionated schemes in many indications as for breast, prostate or rectal cancer, resulting in equivalent outcomes and toxicities, more convenient for patients and favouring shared decision making.

CONCLUSION

Radiation therapy is a dynamic field of research, and many RCTs have greatly impacted therapeutic standards over the last years. Investments in radiotherapy research should facilitate the transfer of innovation to clinic.

Expert consensus on oncological [18F]FDG total-body PET/CT imaging (version 1)

BACKGROUND

[¹⁸F]FDG imaging on total-body PET/CT (TB PET/CT) scanners, with improved sensitivity, offers new potentials for cancer diagnosis, staging, and radiation treatment planning. This consensus provides the protocols for clinical practices with a goal of paving the way for future studies with the total-body scanners in oncological [¹⁸F]FDG TB PET/CT imaging.

METHODS

The consensus was summarized based on the published guidelines and peer-reviewed articles of TB PET/CT in the literature, along with the opinions of the experts from major research institutions with a total of 40,000 cases performed on the TB PET/CT scanners.

RESULTS

This consensus describes the protocols for routine and dynamic [¹⁸F]FDG TB PET/CT scanning focusing on the reduction of imaging acquisition time and FDG injected activity, which may serve as a reference for research and clinic oncological PET/CT studies.

CONCLUSION

This expert consensus focuses on the reduction of acquisition time and FDG injected activity with a TB PET/CT scanner, which may improve the patient throughput or reduce the radiation exposure in daily clinical oncologic imaging.

KEY POINTS

• [¹⁸F]FDG-imaging protocols for oncological total-body PET/CT with reduced acquisition time or with different FDG activity levels have been summarized from multicenter studies. • Total-body PET/CT provides better image quality and improved diagnostic insights. • Clinical workflow and patient management have been improved.

Clinical Efficacy of Osimertinib in Patients with Advanced Non-Small Cell Lung Cancer and Its Effect on Serum CEA and VEGF Expression

Objective

To assess the clinical efficacy of osimertinib in patients with advanced non-small cell lung cancer and its effect on serum carcinoembryonic antigen (CEA) and vascular endothelial growth factor (VEGF) expression.

Methods

Between July 2018 and January 2020, 80 patients with advanced non-small cell lung cancer were assessed for eligibility and recruited. The patients were assigned at a ratio of 1 : 1 to receive either the PC regimen (pemetrexed + cisplatin) (conventional group) or osimertinib (experimental group). The primary endpoint was the clinical efficacy, and the secondary endpoints were the adverse events, expression of serum CEA and VEGF, and 2-year survival.

Results

Osimertinib was associated with a significantly higher response rate and disease control rate versus pemetrexed plus cisplatin (P < 0.05). Osimertinib resulted in a significantly lower incidence of adverse events versus the PC regimen (P < 0.05). Patients given osimertinib had significantly lower levels of CEA and VEGF versus those given pemetrexed plus cisplatin (P < 0.05). Osimertinib was associated with a significantly higher 1-year and 2-year survival rate versus pemetrexed plus cisplatin.

Conclusion

Osimertinib could inhibit the expression of serum CEA and VEGF in patients with advanced non-small cell lung cancer and reduce the adverse events with significant efficacy, so it is worthy of clinical promotion and application.

GOECP/SEOR radiotheraphy guidelines for non-small-cell lung cancer

Non-small cell lung cancer (NSCLC) is a heterogeneous disease accounting for approximately 85% of all lung cancers. Only 17% of patients are diagnosed at an early stage. Treatment is multidisciplinary and radiotherapy plays a key role in all stages of the disease. More than 50% of patients with NSCLC are treated with radiotherapy (curative-intent or palliative). Technological advances-including highly conformal radiotherapy techniques, new immobilization and respiratory control systems, and precision image verification systems-allow clinicians to individualize treatment to maximize tumor control while minimizing treatment-related toxicity. Novel therapeutic regimens such as moderate hypofractionation and advanced techniques such as stereotactic body radiotherapy (SBRT) have reduced the number of radiotherapy sessions. The integration of SBRT into routine clinical practice has radically altered treatment of early-stage disease. SBRT also plays an increasingly important role in oligometastatic disease. The aim of the present guidelines is to review the role of radiotherapy in the treatment of localized, locally-advanced, and metastatic NSCLC. We review the main radiotherapy techniques and clarify the role of radiotherapy in routine clinical practice. These guidelines are based on the best available evidence. The level and grade of evidence supporting each recommendation is provided.

Open issues in the therapeutic management of unresectable stage III NSCLC in the immunotherapy era

Treatment of stage III non-small cell lung cancer (NSCLC) has traditionally been controversial and challenging: multidisciplinary approach is mandatory and defining resectability is a critical issue; furthermore, patients are often frail due to age or comorbidities. After PACIFIC trial publication, a new therapeutic path has been defined for patients with unresectable NSCLC, with a prominent prognostic advantage. A trimodality treatment, with chemo-radiotherapy followed by maintenance durvalumab is now the standard of care, recommended by international guidelines. However, despite an impressive activity, the use of consolidative immunotherapy after concurrent chemoradiotherapy is highly debated in some clinically-relevant situations, including patients harboring EGFR mutations, older and/or frail patients not suitable for combined treatment, PD-L1 tumor expression. Here we report an expert virtual Italian meeting summary, where six medical oncologists and six radiation oncologists discussed all these aspects trying to underline the critical aspects and to find the possible clinical solutions.

A Comparison of Isotoxic Dose-escalated Radiotherapy in Lung Cancer with Moderate Deep Inspiration Breath Hold, Mid-ventilation and Internal Target Volume Techniques

AIMS

With interest in normal tissue sparing and dose-escalated radiotherapy in the treatment of inoperable locally advanced non-small cell lung cancer, this study investigated the impact of motion-managed moderate deep inspiration breath hold (mDIBH) on normal tissue sparing and dose-escalation potential and compared this to planning with a four-dimensional motion-encompassing internal target volume or motion-compensating mid-ventilation approach.

MATERIALS AND METHODS

Twenty-one patients underwent four-dimensional and mDIBH planning computed tomography scans. Internal and mid-ventilation target volumes were generated on the four-dimensional scan, with mDIBH target volumes generated on the mDIBH scan. Isotoxic target dose-escalation guidelines were used to generate six plans per patient: three with a target dose cap and three without. Target dose-escalation potential, normal tissue complication probability and differences in pre-specified dose-volume metrics were evaluated for the three motion-management techniques.

RESULTS

The mean total lung volume was significantly greater with mDIBH compared with four-dimensional scans. Lung dose (mean and V21 Gy) and mean heart dose were significantly reduced with mDIBH in comparison with four-dimensional-based approaches, and this translated to a significant reduction in heart and lung normal tissue complication probability with mDIBH. In 20/21 patients, the trial target prescription dose cap of 79.2 Gy was achievable with all motion-management techniques.

CONCLUSION

mDIBH aids lung and heart dose sparing in isotoxic dose-escalated radiotherapy compared with four-dimensional planning techniques. Given concerns about lung and cardiac toxicity, particularly in an era of consolidation immunotherapy, reduced normal tissue doses may be advantageous for treatment tolerance and outcome.

Joint EANM/SNMMI/ESTRO practice recommendations for the use of 2-[18F]FDG PET/CT external beam radiation treatment planning in lung cancer V1.0

PURPOSE

2-[18F]FDG PET/CT is of utmost importance for radiation treatment (RT) planning and response monitoring in lung cancer patients, in both non-small and small cell lung cancer (NSCLC and SCLC). This topic has been addressed in guidelines composed by experts within the field of radiation oncology. However, up to present, there is no procedural guideline on this subject, with involvement of the nuclear medicine societies.

METHODS

A literature review was performed, followed by a discussion between a multidisciplinary team of experts in the different fields involved in the RT planning of lung cancer, in order to guide clinical management. The project was led by experts of the two nuclear medicine societies (EANM and SNMMI) and radiation oncology (ESTRO).

RESULTS AND CONCLUSION

This guideline results from a joint and dynamic collaboration between the relevant disciplines for this topic. It provides a worldwide, state of the art, and multidisciplinary guide to 2-[18F]FDG PET/CT RT planning in NSCLC and SCLC. These practical recommendations describe applicable updates for existing clinical practices, highlight potential flaws, and provide solutions to overcome these as well. Finally, the recent developments considered for future application are also reviewed.

Differential role of residual metabolic tumor volume in inoperable stage III NSCLC after chemoradiotherapy ± immune checkpoint inhibition

BACKGROUND

The PET-derived metabolic tumor volume (MTV) is an independent prognosticator in non-small cell lung cancer (NSCLC) patients. We analyzed the prognostic value of residual MTV (rMTV) after completion of chemoradiotherapy (CRT) in inoperable stage III NSCLC patients with and without immune checkpoint inhibition (ICI).

METHODS

Fifty-six inoperable stage III NSCLC patients (16 female, median 65.0 years) underwent 18F-FDG PET/CT after completion of standard CRT. rMTV was delineated on 18F-FDG PET/CT using a standard threshold (liver SUVmean + 2 × standard deviation). 21/56 patients underwent additional ICI (CRT-IO, 21/56 patients) thereafter. Patients were divided in volumetric subgroups using median split dichotomization (MTV ≤ 4.3 ml vs. > 4.3 ml). rMTV, clinical features, and ICI-application were correlated with clinical outcome parameters (progression-free survival (PFS), local PFS (LPFS), and overall survival (OS).

RESULTS

Overall, median follow-up was 52.0 months. Smaller rMTV was associated with longer median PFS (29.3 vs. 10.5 months, p = 0.015), LPFS (49.9 vs. 13.5 months, p = 0.001), and OS (63.0 vs. 23.0 months, p = 0.003). CRT-IO patients compared to CRT patients showed significantly longer median PFS (29.3 vs. 11.2 months, p = 0.034), LPFS (median not reached vs. 14.0 months, p = 0.016), and OS (median not reached vs. 25.2 months, p = 0.007). In the CRT subgroup, smaller rMTV was associated with longer median PFS (33.5 vs. 8.6 months, p = 0.001), LPFS (49.9 vs. 10.1 months, p = 0.001), and OS (63.0 vs. 16.3 months, p = 0.004). In the CRT-IO subgroup, neither PFS, LPFS, nor OS were associated with MTV (p > 0.05 each). The findings were confirmed in subsequent multivariate analyses.

CONCLUSION

In stage III NSCLC, smaller rMTV is highly associated with superior clinical outcome, especially in patients undergoing CRT without ICI. Patients with CRT-IO show significantly improved outcome compared to CRT patients. Of note, clinical outcome in CRT-IO patients is independent of residual MTV. Hence, even patients with large rMTV might profit from ICI despite extensive tumor load.

A Novel Radiomics-Based Tumor Volume Segmentation Algorithm for Lung Tumors in FDG-PET/CT after 3D Motion Correction—A Technical Feasibility and Stability Study

Positron emission tomography (PET) provides important additional information when applied in radiation therapy treatment planning. However, the optimal way to define tumors in PET images is still undetermined. As radiomics features are gaining more and more importance in PET image interpretation as well, we aimed to use textural features for an optimal differentiation between tumoral tissue and surrounding tissue to segment-target lesions based on three textural parameters found to be suitable in previous analysis (Kurtosis, Local Entropy and Long Zone Emphasis). Intended for use in radiation therapy planning, this algorithm was combined with a previously described motion-correction algorithm and validated in phantom data. In addition, feasibility was shown in five patients. The algorithms provided sufficient results for phantom and patient data. The stability of the results was analyzed in 20 consecutive measurements of phantom data. Results for textural feature-based algorithms were slightly worse than those of the threshold-based reference algorithm (mean standard deviation 1.2%—compared to 4.2% to 8.6%) However, the Entropy-based algorithm came the closest to the real volume of the phantom sphere of 6 ccm with a mean measured volume of 26.5 ccm. The threshold-based algorithm found a mean volume of 25.0 ccm. In conclusion, we showed a novel, radiomics-based tumor segmentation algorithm in FDG-PET with promising results in phantom studies concerning recovered lesion volume and reasonable results in stability in consecutive measurements. Segmentation based on Entropy was the most precise in comparison with sphere volume but showed the worst stability in consecutive measurements. Despite these promising results, further studies with larger patient cohorts and histopathological standards need to be performed for further validation of the presented algorithms and their applicability in clinical routines. In addition, their application in other tumor entities needs to be studied.

PET/CT-based adaptive radiotherapy of locally advanced non-small cell lung cancer in multicenter yDEGRO ARO 2017-01 cohort study

BACKGROUND

Stage III non-small cell lung cancer (NSCLC) represents a highly heterogeneous disease and treatment burden. Advances in imaging modality show promising results for radiotherapy planning. In this multicentric study, we evaluated the impact of PET/CT-based radiotherapy planning on the prognosis of patients with stage III NSCLC.

METHOD AND PATIENTS

A retrospective observational cohort study (ARO 2017-01/NCT03055715) was conducted by the young DEGRO trial group of the German Society for Radiation Oncology (DEGRO) with the primary objective to assess the effect of tumour volume change during chemoradiotherapy and the secondary objective to assess the effect of treatment planning on survival. Three hundred forty-seven patients with stage III NSCLC treated at 21 university centers between January 2010 and December 2013 were enrolled in this trial. Patients received primary curative chemoradiotherapy with an intended dose of 50 Gy (hypofractionated) or > 60 Gy (normofractionated). To assess the effect of radiotherapy planning modality on overall survival, we used multivariate frailty models. Models were adjusted for gross tumor volume at the initiation of therapy, age, sex, simultaneous chemotherapy, lung comorbidities, RT dose and tumor grade. By considering the random effect, we can account for heterogeneity in survival and considered covariates within the model in relation to the study side.

RESULTS

Patients were predominantly male (n = 269, 78.4%) with mainly adenocarcinoma (56.4%) and an average of 67.2 years. Adaptation of radiotherapy with consecutive reduction of irradiation volume showed no significant disadvantage for patient survival (HR = 1.21, 95% CI 0.89-1.64). The use of PET/CT co-registration in radiation planning tended to result in better oncologic outcomes, although no significant association could be shown (HR = 0.8, 95% CI 0.56-1.16). Centers with a consistent planning strategy performed better than those without a preferred planning method (0.62, 95% CI 0.41-0.94).

CONCLUSION

A consistent planning strategy has positive effects on overall survival. The use of PET/CT-based adaptive radiotherapy planning shows a similar survival prospect with the prospective of lower treatment volumes. In future research, toxicities need to be analysed in order to assess such reasoning.

Radiotherapy for primary lung cancer

Herein are presented the recommendations from the Société française de radiothérapie oncologique regarding indications and modalities of lung cancer radiotherapy. The recommendations for delineation of the target volumes and organs at risk are detailed.

ProCaLung - Peer review in stage III, mediastinal node-positive, non-small-cell lung cancer: How to benchmark clinical practice of nodal target volume definition and delineation in Belgium☆

BACKGROUND AND PURPOSE

The Quality Assurance project for stage III non-small cell lung cancer radiotherapy ProCaLung performed a multicentric two-step exercise evaluating mediastinal nodal Target Volume Definition and Delineation (TVD) variability and the opportunity for standardization. The TVD variability before and after providing detailed guidelines and the value of qualitative contour reviewing before applying quantitative measures were investigated.

MATERIALS AND METHODS

The case of a patient with stage III NSCLC and involved mediastinal lymph nodes was used as a basis for this study. Twenty-two radiation oncologists from nineteen centers in Belgium and Luxembourg participated in at least one of two phases of the project (before and after introduction of ProCaLung contouring guidelines). The resulting thirty-three mediastinal nodal GTV and CTV contours were then evaluated using a qualitative-before-quantitative (QBQ) approach. First, a qualitative analysis was performed, evaluating adherence to most recent guidelines. From this, a list of observed deviations was created and these were used to evaluate contour conformity. The second analysis was quantitative, using overlap and surface distance measures to compare contours within qualitative groups and between phases. A 'most robust' reference volume for these analyses was created using the STAPLE-algorithm and an averaging method.

RESULTS

Five GTV and seven CTV qualitative groups were identified. Second step contours were more often in higher-conformity groups (p = 0.012 for GTV and p = 0.024 for CTV). Median Residual Mean Square Distances improved from 2.34 mm to 1.36 mm for GTV (p = 0.01) and from 4.53 mm to 1.58 mm for CTV (p < 0.0001). Median Dice coefficients increased from 0.81 to 0.84 for GTV (p = 0.07) and from 0.82 to 0.89 for CTV (p ≤ 0.001). Using HC-contours only to generate references translated in more robust quantitative evaluations.

CONCLUSION

Variability of mediastinal nodal TVD was reduced after providing the ProCaLung consensus guidelines. A qualitative review was essential for providing meaningful quantitative measures.

Revisiting neoadjuvant therapy in non-small-cell lung cancer

Despite the rapidly evolving treatment landscape in advanced non-small-cell lung cancer (NSCLC), developments in neoadjuvant and adjuvant treatments have been nascent by comparison. Establishing overall survival benefit in the early-stage setting has been challenging because of the need for large trials and long-term survival data. Encouraged by improved treatment outcomes with a biomarker-driven approach in advanced NSCLC, and recognising the need to improve survival outcomes in early-stage NSCLC, there has been renewed interest in revisiting neoadjuvant strategies. Multiple neoadjuvant trials with targeted therapy and immunotherapy, either alone or in combination with chemotherapy, have yielded unique insights into traditional response parameters, such as the discordance between RECIST response and pathological response, and expanded opportunities for biomarker discovery. With further standardisation of trial endpoints across studies, coupled with the implementation of novel technologies including radiomics and digital pathology, individual risk-stratified neoadjuvant treatment approaches are poised to make a striking impact on the outcomes of early-stage NSCLC.

PET/CT imaging for evaluation of multimodal treatment efficacy and toxicity in advanced NSCLC-current state and future directions

PURPOSE

The advent of immune checkpoint inhibitors (ICIs) has revolutionized the treatment of advanced NSCLC, leading to a string of approvals in recent years. Herein, a narrative review on the role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in the ever-evolving treatment landscape of advanced NSCLC is presented.

METHODS

This comprehensive review will begin with an introduction into current treatment paradigms incorporating ICIs; the evolution of CT-based criteria; moving onto novel phenomena observed with ICIs and the current state of hybrid imaging for diagnosis, treatment planning, evaluation of treatment efficacy and toxicity in advanced NSCLC, also taking into consideration its limitations and future directions.

CONCLUSIONS

The advent of ICIs marks the dawn of a new era bringing forth new challenges particularly vis-à-vis treatment response assessment and observation of novel phenomena accompanied by novel systemic side effects. While FDG PET/CT is widely adopted for tumor volume delineation in locally advanced disease, response assessment to immunotherapy based on current criteria is of high clinical value but has its inherent limitations. In recent years, modifications of established (PET)/CT criteria have been proposed to provide more refined approaches towards response evaluation. Not only a comprehensive inclusion of PET-based response criteria in prospective randomized controlled trials, but also a general harmonization within the variety of PET-based response criteria is pertinent to strengthen clinical implementation and widespread use of hybrid imaging for response assessment in NSCLC.

Isotoxic investigation of 18F-FDG PET/CT-guided dose escalation with intensity-modulated radiotherapy for LA-NSCLC

PURPOSE

This research compared differences of dosimetric and biological parameters between PET/CT-guided isotoxic SIB-IMRT plans and conventional radiotherapy plans for patients with LA-NSCLC, and it also evaluated the factors that affect dose escalation.

MATERIALS AND METHODS

This study consisted of a retrospective cohort of thirty patients with IIIA-IIIB NSCLC. SIB-IMRT (Plan_iso) and conventional radiotherapy (Plan_primary) plans were generated using auto-planning. Dosimetric parameters such as mean lung dose (MLD) and other indicators were compared. Tumor control probability (TCP) of PTV and normal tissue complication probability (NTCP) of total lung, heart, esophagus, and spinal cord were calculated. The relationships between dose escalation and 3 D length of PTV and other factors were analyzed. Paired-samples t-test, Mann-Whitney U test, and Chi-Square test were performed for comparisons between datasets. A P < .05 was considered statistically significant.

RESULTS

The dosimetric parameters of PTV in Plan_iso were higher than those of PTV in Plan_primary, and there were significant differences (p < .05). Compared with Plan_primary, Plan_iso slightly increased dosimetric parameters of the total lung, heart, spinal cord, esophagus, and MUs. The absolute differences were small. TCPs of PTV in Plan_iso were significantly higher than those in Plan_primary. NTCPs of the total lung, esophagus, and spinal cord in Plan_iso were higher than those in Plan_primary. There were significant differences, but the absolute differences were small. NTCP of heart in Plan_iso was slightly higher than that in Plan_primary, but there was no statistical difference.

CONCLUSIONS

For LA-NSCLC, the SIB based on isotoxic radiotherapy can significantly increase TCP under the premise that the toxicity of OARs is comparable.

Patterns of nodal spread in stage III NSCLC: importance of EBUS-TBNA and 18F-FDG PET/CT for radiotherapy target volume definition

Purpose

The aim of this study was to compare the pattern of intra-patient spread of lymph-node (LN)-metastases within the mediastinum as assessed by ¹⁸F-FDG PET/CT and systematic endobronchial ultrasound-guided transbronchial-needle aspiration (EBUS-TBNA) for precise target volume definition in stage III NSCLC.

Methods

This is a single-center study based on our preceding investigation, including all consecutive patients with initial diagnosis of stage IIIA-C NSCLC, receiving concurrent radiochemotherapy (12/2011–06/2018). Inclusion criteria were curative treatment intent, ¹⁸F-FDG PET/CT and EBUS-TBNA prior to start of treatment. The lymphatic drainage was classified into echelon-1 (ipsilateral hilum), echelon-2 (ipsilateral LN-stations 4 and 7) and echelon-3 (rest of the mediastinum, contralateral hilum). The pattern of spread was classified according to all permutations of echelon-1, echelon-2, and echelon-3 EBUS-TBNA findings.

Results

In total, 180 patients were enrolled. Various patterns of LN-spread could be identified. Skip lesions with an involved echelon distal from an uninvolved one were detected in less than 10% of patients by both EBUS-TBNA and PET. The pattern with largest asymmetry was detected in cases with EBUS-TBNA- or PET-positivity at all three echelons (p < 0.0001, exact symmetry test). In a multivariable logistic model for EBUS-positivity at echelon-3, prognostic factors were PET-positivity at echelon-3 (Hazard ratio (HR) = 12.1; 95%-CI: 3.2–46.5), EBUS-TBNA positivity at echelon-2 (HR = 6.7; 95%-CI: 1.31–31.2) and left-sided tumor location (HR = 4.0; 95%-CI: 1.24–13.2). There were significantly less combined ipsilateral upper (LN-stations 2 and 4) and lower (LN-station 7) mediastinal involvements (16.8% of patients) with EBUS-TBNA than with PET (38.9%, p < 0.0001, exact symmetry test). EBUS-TBNA detected a lobe specific heterogeneity between the odds ratios of LN-positivity in the upper versus lower mediastinum (p = 0.0021, Breslow-Day test), while PET did not (p = 0.19).

Conclusion

Frequent patterns of LN-metastatic spread could be defined by EBUS-TBNA and PET and discrepancies in the pattern were seen between both methods. EBUS-TBNA showed more lobe and tumor laterality specific patterns of LN-metastases than PET and skipped lymph node stations were rare. These systematic relations offer the opportunity to further refine multi-parameter risk of LN-involvement models for target volume delineation based on pattern of spread by EBUS-TBNA and PET.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13014-021-01904-4.

Impact of radiotherapy protocol adherence in NSCLC patients treated with concurrent chemoradiation: RTQA results of the PET-Plan trial

INTRODUCTION

The success of intensification and personalisation of the curative treatment of non-small cell lung cancer (NSCLC) is strongly associated with the precision in radiotherapy. Here, we evaluate the impact of radiotherapy protocol adherence in a prospective multicentre trial.

METHODS

In the open-label, randomised, controlled PET-Plan trial, patients with inoperable NSCLC were randomized at a 1:1 ratio regarding the target volume delineation informed by ¹F-FDG PET and CT plus elective nodal irradiation (arm A) or target volumes informed by PET alone (arm B) and received iso-toxically dose-escalated concurrent chemoradiation. The prospectively organised quality assurance program (RTQA) included individual case review by predefined criteria. For evaluation, protocol adherence was scored as per protocol (pP), with minor (miD), intermediate (inD) and major (maD) deviations. In order to exclude biases through patients who discontinued treatment, patients who received ≥60 Gy were additionally analysed.

RESULTS

Between 05/2009-11/2016, 205 patients were randomized, 204 patients started treatment according to protocol of which 31 (15%) patients had maD. Patients with maD had an inferior overall survival (OS) (HR 2.9, 95% CI 1.8-4.4, p < 0.0001) and a higher risk of loco-regional progression (HR 5.7, 95% CI 2.7-11.1, p < 0.0001). These results were significant also in the subgroup of patients receiving ≥ 60 Gy. Patients with maD concerning normal tissue delineation and/or dose constraints had a worse OS (p = 0.006) although no higher incidence of grade ≥ 3 toxicities.

CONCLUSIONS

Non-adherence to the radiotherapy protocol was associated with an inferior OS and loco-regional control. These results underline the importance of RTQA.

Value of PET imaging for radiation therapy

This comprehensive review written by experts in their field gives an overview on the current status of incorporating positron emission tomography (PET) into radiation treatment planning. Moreover, it highlights ongoing studies for treatment individualisation and per-treatment tumour response monitoring for various primary tumours. Novel tracers and image analysis methods are discussed. The authors believe this contribution to be of crucial value for experts in the field as well as for policy makers deciding on the reimbursement of this powerful imaging modality.

Value of PET imaging for radiation therapy

This comprehensive review written by experts in their field gives an overview on the current status of incorporating positron emission tomography (PET) into radiation treatment planning. Moreover, it highlights ongoing studies for treatment individualisation and per-treatment tumour response monitoring for various primary tumours. Novel tracers and image analysis methods are discussed. The authors believe this contribution to be of crucial value for experts in the field as well as for policy makers deciding on the reimbursement of this powerful imaging modality.

Developments in radiation techniques for thoracic malignancies

Radiation therapy is a cornerstone of modern lung cancer treatment alongside surgery, chemotherapy, immunotherapy and targeted therapies. Advances in radiotherapy techniques have enhanced the accuracy of radiation delivery, which has contributed to the evolution of radiation therapy into a guideline-recommended treatment in both early-stage and locally advanced nonsmall cell lung cancer. Furthermore, although radiotherapy has long been used for palliation of disease in advanced lung cancer, it is increasingly having a role as a locally ablative treatment in patients with oligometastatic disease.This review provides an overview of recent developments in radiation techniques, particularly for non-radiation oncologists who are involved in the care of lung cancer patients. Technical advances are discussed, and findings of recent clinical trials are highlighted, all of which have led to a changing perception of the role of radiation therapy in multidisciplinary care.

Total-body PET/CT using half-dose FDG and compared with conventional PET/CT using full-dose FDG in lung cancer

PURPOSE

The purpose was to explore the effects of total-body PET/CT with half-dose 18F-FDG activity on image quality, compared with those of conventional PET/CT with clinical routine full-dose 18F-FDG in lung cancer.

METHODS

Fifty-six primary lung cancer patients who underwent total-body PET/CT on a uEXPLORER scanner with half-dose (1.85 MBq/kg) 18F-FDG activity before treatment were retrospectively studied; among them, 28 patients were confirmed by postoperative pathologic examination and 28 patients by biopsy. After matching with the pathological study results, the other 28 patients with lung cancer who underwent surgery were selected for the full-dose (3.70 MBq/kg) group. Patients in the full-dose group were studied with a conventional uM780 PET/CT scanner. The acquisition time of the half-dose group was 15 min, split into 4-min and 2-min duration groups, which were all referred to as G15, G4 and G2, respectively. The PET/CT scanning speed in the full-dose group was 2 min/bed. Image quality was evaluated by subjective and objective analyses. The subjective analysis method was carried out with a 5-point scale (5-excellent, 1-poor). Objective analysis indicators of PET image quality included the SUVmax, SUVmean and signal-to-noise ratio (SNR) of the liver; the SUVmax and SUVmean of the blood pool; and the SUVmax and tumour-to-background ratio (TBR) of the lesions. G15 served as the reference for G2 and G4 to test lesion detectability.

RESULTS

Image quality scores in G2 (4.3 ± 0.7) were significantly higher than those in the full-dose group (3.7 ± 0.6) (p = 0.004). The mean and SD of the image quality scores in G4 and G15 were 4.9 ± 0.2 and 5.0 ± 0.0, respectively. The liver SNR in G2 was significantly higher than that in the full-dose group; the corresponding SNR were 11.7 ± 1.5 and 8.3 ± 1.2 (p < 0.001), respectively. The liver SNR significantly increased with the time of acquisition among G2, G4 and G15 (11.1 ± 1.7, 15.2 ± 3.4 and 30.5 ± 6.0, all p < 0.05). G15 served as the reference, and all these lesions (100%) could be identified by G2 and G4.

CONCLUSION

Total-body PET/CT with half-dose 18F-FDG activity in G2 and G4 achieved comparable image quality to conventional PET/CT, and its image quality was better than that of conventional PET/CT with clinical routine full-dose 18F-FDG in lung cancer.

New developments in locally advanced nonsmall cell lung cancer

Locally advanced nonsmall cell lung cancer, due to its varying prognosis, is grouped according to TNM stage IIIA, IIIB and IIIC. Developments over the last 3 years have been focused on the integration of immunotherapy into the combination treatment of a locally definitive therapy (surgery or radiotherapy) and chemotherapy. For concurrent chemoradiotherapy, consolidation therapy with durvalumab was established. Adjuvant targeted therapy has again gained increasing interest. In order to adapt treatment to the specific stage subgroup and its prognosis, fluorodeoxyglucose positron emission tomography/computed tomography and pathological evaluation of the mediastinum are important. Tumours should be investigated for immunological features and driver mutations. Regarding toxicity, evaluation of pulmonary and cardiac function, as well as symptoms and quality of life, is of increasing importance. To improve the management and prognosis of this heterogeneous entity, clinical trials and registries should take these factors into account.

A review of the application of machine learning in molecular imaging

Molecular imaging (MI) is a science that uses imaging methods to reflect the changes of molecular level in living state and conduct qualitative and quantitative studies on its biological behaviors in imaging. Optical molecular imaging (OMI) and nuclear medical imaging are two key research fields of MI. OMI technology refers to the optical information generated by the imaging target (such as tumors) due to drug intervention and other reasons. By collecting the optical information, researchers can track the motion trajectory of the imaging target at the molecular level. Owing to its high specificity and sensitivity, OMI has been widely used in preclinical research and clinical surgery. Nuclear medical imaging mainly detects ionizing radiation emitted by radioactive substances. It can provide molecular information for early diagnosis, effective treatment and basic research of diseases, which has become one of the frontiers and hot topics in the field of medicine in the world today. Both OMI and nuclear medical imaging technology require a lot of data processing and analysis. In recent years, artificial intelligence technology, especially neural network-based machine learning (ML) technology, has been widely used in MI because of its powerful data processing capability. It provides a feasible strategy to deal with large and complex data for the requirement of MI. In this review, we will focus on the applications of ML methods in OMI and nuclear medical imaging.

Non-small cell lung cancer stage migration as a function of wait times from diagnostic imaging: A pooled analysis from five international centres

INTRODUCTION

Patients with non-small cell lung cancer (NSCLC) can experience rapid disease progression between initial staging FDG-PET scans and commencement of curative-intent radiotherapy (RT). Previous studies that estimated stage migration rates by comparing staging PET/CT and treatment-planning PET/CT images were limited by small sample sizes.

METHODS

This multicenter, international study combined prospective data from five institutions for PET-staged patients with NSCLC who were intended to receive curative-intent RT. TNM status was compared for staging and RT planning scans and the probability of TNM status and overall stage migration was analyzed as a function of the interval between PET/CT scans. The impacts of N classification, overall stage, and pathology were also studied.

RESULTS

Pooled data from 181 patients were analyzed. The median interval between PET/CT scans was 42 days (range, 2-208). Upstaging occurred in 32 % of patients. The overall rate of stage migration was higher for patients presenting with initial stage IIIB/IIIC disease (p = 0.006) and patients with N2-3 nodal disease (p = 0.019). Upstaging to M1 disease was significantly associated with initial stage IIIB/IIIC disease (HR = 15.2) and adenocarcinoma (HR = 10) histology.

CONCLUSION

Longer intervals between imaging and treatment in patients with NSCLC were associated with high rates disease progression with consequent risks of geographic miss in RT planning and futile treatment in patients with M1 disease. Patients with more extensive initial nodal involvement and those with adenocarcinoma had the highest rates of stage migration. Dedicated RT planning PET/CT imaging is recommended, especially if >3 weeks have elapsed after initial staging.

Evolving target volume concepts in locally advanced non-small cell lung cancer

Radiotherapy (RT) target volume concepts for locally advanced lung cancer have been under discussion for years. Although they may be as important as treatment doses, many aspects of them are still based on conventions, which, due to the paucity of prospective data, rely on long-term practice or on clinical knowledge and experience (e.g., on patterns of spread or recurrence). However, in recent years, large improvements have been made in medical imaging and molecular imaging methods have been implemented, which are of great interest in RT. For lung cancer, in recent years, 18F-fluoro-desoxy-glucose (FDG)-positron-emission tomography (PET)/computed tomography (CT) has shown a superior diagnostic accuracy as compare to conventional imaging and has become an indispensable standard tool for diagnostic workup, staging and response assessment. This offers the chance to optimize target volume concepts in relation to modern imaging. While actual recommendations as the EORTC or ESTRO-ACROP guidelines already include imaging standards, the recently published PET-Plan trial prospectively investigated conventional versus imaging guided target volumes in relation to patient outcome. The results of this trial may help to further refine standards. The current review gives a practical overview on procedures for pre-treatment imaging and target volume delineation in locally advanced non-small cell lung cancer (NSCLC) in synopsis of the procedures established by the PET-Plan trial with the actual EORTC and ACROP guidelines.

Concurrent chemoradiotherapy for stage III non-small-cell lung cancer: recent progress and future perspectives (a narrative review)

Concurrent chemoradiotherapy (CHRT) remains the therapeutic standard for locally advanced inoperable non-small-cell lung cancer (NSCLC). The median overall survival (OS) with this approach is in the range of 20–30 months, with five-year survival of approximately 30%. These outcomes have recently been further improved by supplementing CHRT with maintenance durvalumab, a monoclonal anti-PD-L1 agent. The progress in treatment outcomes of locally advanced NSCLC before the era of immunotherapy has been achieved mainly by virtue of developments in diagnostics and radiotherapy techniques. Routine implementation of endoscopic and endobronchial ultrasonography for mediastinal lymph nodes assessment, positron emission tomography/computed tomography and magnetic resonance imaging of the brain allows for more accurate staging of NSCLC and for optimizing treatment strategy. Thorough staging and respiratory motion control allows for higher conformity of radiotherapy and reduction of radiotherapy related toxicity. Dose escalation with prolonged overall treatment time does not improve treatment outcomes of CHRT. In consequence, 60 Gy in 2 Gy fractions or equivalent biological dose remains the standard dose for definitive CHRT in locally advanced NSCLC. However, owing to increased toxicity of CHRT, this option may not be applicable in a proportion of elderly or frail patients. This article summarizes recent developments in curative CHRT for inoperable stage III NSCLC, and presents perspectives for further improvements of this strategy