Impact of [18F]Fluorodeoxyglucose PET-CT Staging on Treatment Planning in Radiotherapy Incorporating Elective Nodal Irradiation for Non-Small-Cell Lung Cancer: A Prospective Study

PET Molecular Imaging: A Holistic Review of Current Practice and Emerging Perspectives for Diagnosis, Therapeutic Evaluation and Prognosis in Clinical Oncology

PET/CT molecular imaging has been imposed in clinical oncological practice over the past 20 years, driven by its two well-grounded foundations: quantification and radiolabeled molecular probe vectorization. From basic visual interpretation to more sophisticated full kinetic modeling, PET technology provides a unique opportunity to characterize various biological processes with different levels of analysis. In clinical practice, many efforts have been made during the last two decades to standardize image analyses at the international level, but advanced metrics are still under use in practice. In parallel, the integration of PET imaging with radionuclide therapy, also known as radiolabeled theranostics, has paved the way towards highly sensitive radionuclide-based precision medicine, with major breakthroughs emerging in neuroendocrine tumors and prostate cancer. PET imaging of tumor immunity and beyond is also emerging, emphasizing the unique capabilities of PET molecular imaging to constantly adapt to emerging oncological challenges. However, these new horizons face the growing complexity of multidimensional data. In the era of precision medicine, statistical and computer sciences are currently revolutionizing image-based decision making, paving the way for more holistic cancer molecular imaging analyses at the whole-body level.

Treatment patterns and real-world evidence for stage III non-small cell lung cancer in Central and Eastern Europe

Background

The aim of this project was to collect real-world evidence and describe treatment patterns for stage III non-small cell lung cancer in Central and Eastern Europe. Based on real-world evidence, an expert opinion was developed, and the unmet needs and quality indicators were identified.

Patients and methods

A systematic literature search and a multidisciplinary expert panel of 10 physicians from 7 countries used a modified Delphi process to identify quality indicators and unmet needs in patients with stage III non-small cell lung cancer. The profound questionnaire was used to characterize treatment patterns used for stage III non-small cell lung cancer, and a systematic review identified patterns in Central and Eastern Europe. The first questionnaire was completed by a group of medical oncologists, radiation oncologists and pneumologists. The panel of experts attended an in-person meeting to review the results of the questionnaire and to process a second round Delphi. An additional survey was then compiled and completed by the panel.

Results

A complete consensus was reached by the panel of experts on a set of evidence-based clinical recommendations. The experience-based questionnaire generated a highly variable map of treatment patterns within the region. A list of unmet needs and barriers to quality care were developed with near-unanimous consent of the panel of experts.

Conclusions

The current landscape of diagnostic and therapeutic approaches in Central and Eastern European countries is highly variable. We identified several significant barriers, mainly related to the availability of diagnostic and imaging methods and low rates of chemoradiotherapy with curative intention as initial treatment for unresectable stage III NSCLC.

(68)Ga-PSMA-11 PET/CT: a new technique with high potential for the radiotherapeutic management of prostate cancer patients

PURPOSE

Radiotherapy is the main therapeutic approach besides surgery of localized prostate cancer. It relies on risk stratification and exact staging. This report analyses the potential of [(68)Ga]Glu-urea-Lys(Ahx)-HBED-CC ((68)Ga-PSMA-11), a new positron emission tomography (PET) tracer targeting prostate-specific membrane antigen (PSMA) for prostate cancer staging and individualized radiotherapy planning.

METHODS

A cohort of 57 patients with prostate cancer scanned with (68)Ga-PSMA-11 PET/CT for radiotherapy planning was retrospectively reviewed; 15 patients were at initial diagnosis and 42 patients at time of biochemical recurrence. Staging results of conventional imaging, including bone scintigraphy, CT or MRI, were compared with (68)Ga-PSMA ligand PET/CT results and the influence on radiotherapeutic management was quantified.

RESULTS

(68)Ga-PSMA ligand PET/CT had a dramatic impact on radiotherapy application in the presented cohort. In 50.8 % of the cases therapy was changed.

CONCLUSION

The presented imaging technique of (68)Ga-PSMA PET/CT could be a key technology for individualized radiotherapy management in prostate cancer.

Lung cancer

(18)F-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) plays a key role in the evaluation of undiagnosed lung nodules, when primary lung cancer is strongly suspected, or when it has already been diagnosed by other techniques. Although technical factors may compromise characterization of small or highly mobile lesions, lesions without apparent FDG uptake can generally be safely observed, whereas FDG-avid lung nodules almost always need further evaluation. FDG-PET/CT is now the primary staging imaging modality for patients with lung cancer who are being considered for curative therapy with either surgery or definitive radiation therapy.

Definitive reirradiation for locoregionally recurrent non-small cell lung cancer with proton beam therapy or intensity modulated radiation therapy: predictors of high-grade toxicity and survival outcomes

PURPOSE

Intrathoracic recurrence of non-small cell lung cancer (NSCLC) after initial treatment remains a dominant cause of death. We report our experience using proton beam therapy and intensity modulated radiation therapy for reirradiation in such cases, focusing on patterns of failure, criteria for patient selection, and predictors of toxicity.

METHODS AND MATERIALS

A total of 102 patients underwent reirradiation for intrathoracic recurrent NSCLC at a single institution. All doses were recalculated to an equivalent dose in 2-Gy fractions (EQD2). All patients had received radiation therapy for NSCLC (median initial dose of 70 EQD2 Gy), with median interval to reirradiation of 17 months and median reirradiation dose of 60.48 EQD2 Gy. Median follow-up time was 6.5 months (range, 0-72 months).

RESULTS

Ninety-nine patients (97%) completed reirradiation. Median local failure-free survival, distant metastasis-free survival (DMFS), and overall survival times were 11.43 months (range, 8.6-22.66 months), 11.43 months (range, 6.83-23.84 months), and 14.71 (range, 10.34-20.56 months), respectively. Toxicity was acceptable, with rates of grade ≥3 esophageal toxicity of 7% and grade ≥3 pulmonary toxicity of 10%. Of the patients who developed local failure after reirradiation, 88% had failure in either the original or the reirradiation field. Poor local control was associated with T4 disease, squamous histology, and Eastern Cooperative Oncology Group performance status score >1. Concurrent chemotherapy improved DMFS, but T4 disease was associated with poor DMFS. Higher T status, Eastern Cooperative Oncology Group performance status ≥1, squamous histology, and larger reirradiation target volumes led to worse overall survival; receipt of concurrent chemotherapy and higher EQD2 were associated with improved OS.

CONCLUSIONS

Intensity modulated radiation therapy and proton beam therapy are options for treating recurrent non-small cell lung cancer. However, rates of locoregional recurrence and distant metastasis are high, and patients should be selected carefully to maximize the benefit of additional aggressive local therapy while minimizing the risk of adverse side effects.

Lung cancer. Radiotherapy in lung cancer: Actual methods and future trends

This survey is performed to update knowledge about methods and trends in lung cancer radiotherapy. A significant development has been noticed in radiotherapeutic techniques, but also in the identification of clinical prognostic factors. The improvement in the therapeutic line includes: application of the four-dimensional computer tomography (4DCT), taking advantage of positron emission tomography (PET-CT), designing of new computational algorithms, allowing more precise irradiation planning, development of treatment precision verification systems and introducing IMRT techniques in chest radiotherapy. The treatment outcomes have improved with high dose radiotherapy, but other fractionation alternations have been investigated as well.

Modern diagnostic and therapeutic interventional radiology in lung cancer

Imaging has an important role in the multidisciplinary management of primary lung cancer. This article reviews the current state-of-the-art imaging modalities used for the evaluation, staging and post-treatment follow-up and surveillance of lung cancers, and image-guided percutaneous techniques for biopsy to confirm the diagnosis and for local therapy in non-surgical candidates.

Feasibility of proton beam therapy for reirradiation of locoregionally recurrent non-small cell lung cancer

BACKGROUND AND PURPOSE

Options are limited for patients with intrathoracic recurrence of non-small cell lung cancer (NSCLC) who previously received radiation. We report our 5-year experience with the toxicity and efficacy of proton beam therapy (PBT) for reirradiation.

MATERIALS AND METHODS

Thirty-three patients underwent PBT reirradiation for intrathoracic recurrent NSCLC at a single institution. All patients had had RT for NSCLC (median initial dose 63 Gy in 33 fractions), with median interval to reirradiation of 36 months. Median reirradiation dose was 66 Gy (RBE) in 32 fractions. Toxicity was scored with CTCAE v4.0, and survival outcomes were estimated using Kaplan-Meier.

RESULTS

Thirty-one patients (94%) completed reirradiation. At a median 11 months' follow-up, 1-year rates of overall survival, progression-free survival, locoregional control, and distant metastasis-free survival were 47%, 28%, 54%, and 39%. Rates of severe (grade ≥3) toxicity were 9% esophageal, 21% pulmonary; 1 patient had grade 4 esophagitis, and 2 had grade 4 pulmonary toxicity. Nine patients experienced a second in-field failure.

CONCLUSIONS

PBT is an option for treating recurrent NSCLC. However, the rates of locoregional recurrence and distant metastasis are high and the potential for toxicity significant. The risks and benefits of PBT must be carefully weighed in each case.

Use of PET/CT for patient selection and radiation therapy target volume definition in patients with non-small-cell lung cancer

SUMMARY PET scanning is having an increasing impact on the treatment of non-small-cell lung cancer with radiation therapy (RT) and chemoRT. It has a powerful impact on staging, often revealing evidence of more advanced, frequently incurable, disease in patients who would otherwise be considered suitable for treatment with potentially curative definitive RT. Approximately a third of curative RT candidates are found to be unsuitable for this often highly toxic form of treatment after PET, thereby ensuring that this intensive treatment is only given to those patients who might benefit from it. If a patient remains suitable for treatment with RT after PET staging, PET can play a further critical role in the targeting of the RT. Without the use of PET in this way, a quarter of patients or more would experience geographic misses, in which some tumor regions would be either underdosed or excluded entirely from treatment, thereby compromising the chances of a successful outcome. There is emerging evidence that the overall results of treatment with RT can be improved by the appropriate use of PET in non-small-cell lung cancer.

Elective lymph node irradiation late course accelerated hyper-fractionated radiotherapy plus concurrent cisplatin-based chemotherapy for esophageal squamous cell carcinoma: a phase II study

BACKGROUND

In this phase II study, we evaluated the efficacy, toxicity, and patterns of failure of elective lymph node irradiation (ENI) late course accelerated hyper-fractionated radiotherapy (LCAHRT) concurrently with cisplatin-based chemotherapy (CHT) for esophageal squamous cell carcinoma (ESCC).

METHODS

Patients with clinical stage II-IVa (T1-4N0-1M0 or M1a) ESCC were enrolled between 2004 and 2011. Radiation therapy (RT) comprised two courses: The first course of radiation covered the primary and metastatic regional tumors and high risk lymph nodal regions, given at 2 Gy per fraction for a dose of 40 Gy. In the second course, LCAHRT was delivered to the boost volume twice a day for an additional 19.6 Gy in 7 treatment days, using 1.4 Gy per fraction. Two cycles of CHT were given at the beginning of RT.

RESULTS

The median age and Karnofsky performance status were 63 years and 80, respectively. The American Joint Committee on Cancer stage was II in 14 (20.6%) patients, III in 32 (47.1%), and IVa in 22 (32.3%). With a median follow-up of 18.5 months, the overall survival at 1-, 3-, 5-year were 75.5%, 46.5%, 22.7% for whole group patients, versus 78.6%, 49.4%, 39.9% for patients with stage II-III. The patterns of first failure from local recurrence, regional failure, and distant metastasis were seen in 20.6%, 17.6%, and 19.1%, respectively. The most frequent acute high-grade (≥ 3) toxicities were esophagitis and leucopenia, occurred in 26.4% and 32.4%.

CONCLUSIONS

ENI LCAHRT concurrently with CHT was appeared to be an effective regimen for ESCC patient with a favorable and tolerated profile. Further observation with longer time and randomized phase III trial is currently underway.

TRIAL REGISTRATION

ChiCTR-TRC-09000568.

Patterns of failure after postoperative radiotherapy for incompletely resected (R1) non-small cell lung cancer: implications for radiation target volume design

OBJECTIVE

Overall survival (OS) and pattern of failure in R1-resected non-small cell lung cancer (NSCLC) patients treated with 3D-planned postoperative radiotherapy (PORT) was retrospectively evaluated. The outcomes and patterns of failure in patients with (+) and without (-) extracapsular nodal extension (ECE) were compared and analyzed with respect to the radiation target volume design.

MATERIALS AND METHODS

Eighty R1-resected (37 ECE+ and 43 ECE-) patients received PORT (60Gy, 2Gy daily) between 2002 and 2011. Patients with N2 disease received limited elective nodal irradiation (ENI); for pN0-1 disease the use of ENI was optional. Among ECE- (extranodal-R1) patients there were 35 pN0-1 and eight pN2 cases; in pN0-1 patients, patterns of failure and outcomes were analyzed with respect to the use of ENI. Loco-regional failure (LRF) was defined as in-field relapse; isolated nodal failure (INF) was defined as out-of-field regional nodal recurrence occurring without LRF, irrespective of distant metastases.

RESULTS

The actuarial 3-year OS rate was 36.3% (median: 30 months). Three-year OS rates in the ECE- and ECE+ group were 40.4% and 31.4%, with median OS of 31 and 24 months, respectively (p=0.43). In multivariate analysis, the presence of ECE was correlated with OS (HR=3.02; 95% CI: 1.00-9.16; p=0.05). Three-year cumulative incidence of LRF (CILRF) was 14.5% and 15.5% in the ECE- and ECE+ groups, respectively (p=0.98). Three-year cumulative incidence of INF (CIINF) was 14.1% in the ECE- group and 11.1% in the ECE+ group (p=0.76). For pN0-1 patients treated with and without ENI (13 and 22 patients) 3-year CILRF rates were 7.7% and 20.8%, respectively (p=0.20); 3-year CIINF rates were 9.1% and 16.3%, respectively (p=0.65).

CONCLUSION

PORT resulted in a relatively good survival of R1-resected NSCLC patients. Relatively high incidence of INF was found in both ECE+ and ECE- patients. For ECE+ patients, treated with limited ENI, distant failure remains a major concern, so the design of ENI fields seems of lesser importance. Omission of ENI in pN0-1 (extranodal-R1) patients resulted in an unacceptably high incidence of INF. We postulate the use of some form of ENI in this setting.

The role of positron emission tomography/computed tomography in radiation therapy planning for patients with lung cancer

Positron emission tomography (PET)/computed tomography (CT) has rapidly assumed a critical role in the management of patients with locoregionally advanced lung cancers who are candidates for definitive radiation therapy (RT). Definitive RT is given with curative intent, but can only be successful in patients without distant metastasis and if all gross tumor is contained within the treated volume. An increasing body of evidence supports the use of PET-based imaging for selection of patients for both surgery and definitive RT. Similarly, the use of PET/CT images for accurate target volume definition in lung cancer is a dynamic area of research. Most available evidence on PET staging of lung cancer relates to non-small cell lung cancer (NSCLC). In general clinical use, (18)F-fluorodeoxyglucose (FDG) is the primary radiopharmaceutical useful in NSCLC. Other tracers, including proliferation markers and hypoxia tracers, may have significant roles in future. Much of the FDG-PET literature describing the impact of PET on actual patient management has concerned candidates for surgical resection. In the few prospective studies where PET was used for staging and patient selection in NSCLC candidates for definitive RT, 25%-30% of patients were denied definitive RT, generally because PET detected unsuspected advanced locoregional or distant metastatic disease. PET/CT and CT findings are often discordant in NSCLC but studies with clinical-pathological correlation always show that PET-assisted staging is more accurate than conventional assessment. In all studies in which "PET-defined" and "non-PET-defined" RT target volumes were compared, there were major differences between PET and non-PET volumes. Therefore, in cases where PET-assisted and non-PET staging are different and biopsy confirmation is unavailable, it is rational to use the most accurate modality (namely PET/CT) to define the target volume. The use of PET/CT in patient selection and target volume definition is likely to lead to improvements in outcome for patients with NSCLC.

Use of FDG-PET in Radiation Treatment Planning for Thoracic Cancers

Radiotherapy plays an important role in the treatment for thoracic cancers. Accurate diagnosis is essential to correctly perform curative radiotherapy. Tumor delineation is also important to prevent geographic misses in radiotherapy planning. Currently, planning is based on computed tomography (CT) imaging when radiation oncologists manually contour the tumor, and this practice often induces interobserver variability. F-18 fluorodeoxyglucose positron emission tomography (FDG-PET) has been reported to enable accurate staging and detect tumor extension in several thoracic cancers, such as lung cancer and esophageal cancer. FDG-PET imaging has many potential advantages in radiotherapy planning for these cancers, because it can add biological information to conventional anatomical images and decrease the inter-observer variability. FDG-PET improves radiotherapy volume and enables dose escalation without causing severe side effects, especially in lung cancer patients. The main advantage of FDG-PET for esophageal cancer patients is the detection of unrecognized lymph node or distal metastases. However, automatic delineation by FDG-PET is still controversial in these tumors, despite the initial expectations. We will review the role of FDG-PET in radiotherapy for thoracic cancers, including lung cancer and esophageal cancer.

[Role of FDG-PET scanning in stage IIIAN2 non-small cell lung cancer]

Patients with clinical stage IIIAN2 non-small cell lung cancer (NSCLC) are a heterogeneous subgroup in term of prognosis and therapeutic management. The optimal management of this patient group is a major focus for thoracic oncology research and the concept of multimodality treatment has recently been introduced. This approach combines induction chemotherapy or radiochemotherapy followed by surgery in the case of mediastinal lymph node down-staging. positron emission tomography computed tomography with [18F]-fluorodesoxyglucose (FDG-PET) is a molecular and metabolic imaging modality which combines the metabolic data of PET with morphological data from CT. FDG-PET has become a standard in lung cancer management since the different indications listed in the standards, options and recommendations (SOR) of the FNCLCC. However, the potential specific importance of FDG-PET in IIIAN2 patients needs to be addressed further. In this setting, the authors' objective is to review the potential role of metabolic imaging in stage IIIAN2 NSCLC, taking into account new multimodality treatments. In stage IIIAN2, FDG-PET has performed better than morphoradiological imaging for baseline and postinduction lymph node staging, the identification of distant metastasis, and determining prognosis, as well as assessing the response to treatment.

PET scans in radiotherapy planning of lung cancer

Accurate delineation of the primary tumor and of involved lymph nodes is a key requisite for successful curative radiotherapy in non-small cell lung cancer (NSCLC). In recent years, it has become clear that the incorporation of FDG PET-CT scan information into the related processes of patient selection and radiotherapy planning has lead to significant improvements for patients with NSCLC. The use of FDG PET-CT information in radiotherapy planning allows better target volume definition, reduces inter-observer variability and encourages selective irradiation of involved mediastinal lymph nodes. PET-CT also opens the door for innovative radiotherapy delivery and the development of new concepts. However, care must be taken to avoid a variety of technical pitfalls and specific education is necessary, for clinicians and physicists alike.

[Radiotherapy of lung cancer: Any room left for elective mediastinal irradiation in 2011?]

Traditionally, the target volumes of curative-intent radiotherapy for non-small cell lung cancer include all uninvolved mediastinal nodes. However, an improvement in tumour control requires an increase of the total dose to the macroscopic target volume. This is only achievable if the irradiation of the organs at risk is reduced, i.e. elective irradiation of the mediastinum is omitted. The available data suggest that elective mediastinal irradiation may be safely omitted, provided that an adequate staging procedure, including FDG PET-CT, has been performed.