Reirradiation for locoregionally recurrent non-small cell lung cancer

Stereotactic boost on residual disease after external-beam irradiation in clinical stage III non-small cell lung cancer: mature results of stereotactic body radiation therapy post radiation therapy (SBRTpostRT) study

PURPOSE

To evaluate the role of stereotactic body radiation therapy (SBRT) delivered after external-beam fractionated irradiation in non-small-cell lung cancer (NSCLC) patients with clinical stage III A, B.

MATERIALS AND METHODS

All patients received three-dimensional conformal radiotherapy (3D-CRT) or intensity modulated radiation therapy (IMRT) (60-66 Gy/30-33 fractions of 2 Gy/5 days a week) with or without concomitant chemotherapy. Within 60 days from the end of irradiation, a SBRT boost (12-22 Gy in 1-3 fractions) was delivered on the residual disease.

RESULTS

Here we report the mature results of 23 patients homogeneously treated and followed up for a median time of 5.35 years (range 4.16-10.16). The rate of overall clinical response after external beam and stereotactic boost was 100%. No treatment-related mortality was recorded. Radiation-related acute toxicities with a grade ≥ 2 were observed in 6/23 patients (26.1%): 4/23 (17.4%) had esophagitis with mild esophageal pain (G2); in 2/23 (8.7%) clinical radiation pneumonitis G2 was observed. Lung fibrosis (20/23 patients, 86.95%) represented a typical late tissue damage, which was symptomatic in one patient. Median disease-free survival (DFS) and overall survival (OS) were 27.8 (95% CI, 4.2-51.3) and 56.7 months (95% CI, 34.9-78.5), respectively. Median local progression-free survival (PFS) was 17 months (range 11.6-22.4), with a median distant PFS of 18 months (range 9.6-26.4). The 5-year actuarial DFS and OS rates were 28.7% and 35.2%, respectively.

CONCLUSIONS

We confirm that a stereotactic boost after radical irradiation is feasible in stage III NSCLC patients. All fit patients who have no indication to adjuvant immunotherapy and presenting residual disease after curative irradiation could benefit from stereotactic boost because outcomes seem to be better than might be historically assumed.

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.

Toxicity of Proton Therapy versus Photon Therapy on Salvage Re-Irradiation for Non-Small Cell Lung Cancer

This study evaluated the toxicity associated with radiation techniques on curative re-irradiation (re-RT) in patients with thoracic recurrence of non-small cell lung cancer (NSCLC). From 2011 to 2019, we retrospectively reviewed the data of 63 patients with salvage re-RT for in-field or marginal recurrence of NSCLC at two independent institutions. Re-RT techniques using X-ray beams and proton beam therapy (PBT) were also included. Re-RT had a 2-year overall survival (OS) and local progression-free survival of 48.0% and 52.0%, respectively. Fifteen patients experienced grade 3 or higher toxicity after re-RT. The complication rates were 18.2% (4/22) and 26.8% (11/41) in PBT patients and X-ray patients, respectively. Airway or esophageal fistulas occurred in seven patients (11.1%). Fistulas or severe airway obstruction occurred in patients with tumors adjacent to the proximal bronchial tree and esophagus, who underwent hypofractionated radiotherapy (RT) or concurrent chemotherapy, and with a higher dose exposure to the esophagus. In conclusion, salvage re-RT was feasible even in patients with local recurrence within the previous RT field. PBT showed similar survival outcomes and toxicity to those of other techniques. However, thoracic re-RT should be performed carefully considering tumor location and RT regimens such as the fraction size and concurrent chemotherapy.

Re-Irradiation of Recurrent Non-Small Cell Lung Cancer

Locoregional recurrence occurs in 10%-30% of non-small cell lung cancer (NSCLC) after treatment with definitive (chemo)radiotherapy. Re-irradiation is the main curative-intent treatment option for these patients; however, it represents a therapeutic challenge for thoracic radiation oncologists. Re-irradiation practices are variable worldwide with lack of agreement on the optimal dose or the cumulative maximum dose acceptable for critical organs. The role of re-irradiation in NSCLC is also not clearly defined in the era of immunotherapy. In this review, we will present published and on-going re-irradiation studies for recurrent NSCLC. We will appraise available evidence for critical organ dose constraints and provide a framework for future therapeutic approaches and trials.

Circulating Exosomal miR-96 as a Novel Biomarker for Radioresistant Non-Small-Cell Lung Cancer

Patients with non-small-cell lung cancer (NSCLC) frequently develop radioresistance, resulting in poor response to radiation and unfavourable prognosis. Early detection of radioresistance hence can guide the adjustment of treatment regimens in time. Exosomes are lipid bilayer-enclosed vesicles with sub-micrometer size that are released by various cells. Exosomes contain a tissue-specific signature wherein a variety of proteins and nucleic acids are selectively packaged. Growing evidence shows exosomes are involved in cancer pathophysiology and exosomes as the latest addition to the liquid biopsy portfolio have been used in cancer diagnosis. Compared to cell free RNA, exosomal lipid envelope can effectively protect RNA cargo against degradation. Therefore, exosomes may hold great promise for the identification of radioresistance. Here, we report six plasma exosomal miRNAs could be used to distinguish radioresistant NSCLC patients from radiosensitive NSCLC patients and to evaluate the prognosis of NSCLC. Samples were obtained from 52 NSCLC patients with or without radioresistance and 45 age-matched healthy volunteers. Exosomes in 1 ml plasma were isolated followed by extraction of small RNA. The expression levels of miRNAs were determined by quantitative real-time PCR. Potential miRNA markers were further evaluated in additional 52 NSCLC patients. We found exosomal miR-1246 and miR-96 are significantly overexpressed in NSCLC patients. Moreover, exosomal miR-96 in patients with radioresistant NSCLC is significantly higher than that of controls. Exosomal miR-96 also demonstrates a significant correlation with vascular invasion and poor overall survival. Altogether, our results indicate that exosomal miR-96 could be a non-invasive diagnostic and prognostic marker of radioresistant NSCLC.

The Impact of Radiotherapy on the Incidence of Secondary Malignancies: A Pan-Cancer Study in the US SEER Cancer Registries

The population of cancer patients with second primary malignancies (SPMs) is rapidly growing. The relationship between radiotherapy and SPMs for some types of tumors is unknown or debated. In this study, we identify 24 types of first primary malignancies (FPMs) between 2004 and 2015 in the Surveillance, Epidemiology, and End Results (SEER) database. Patients in the radiotherapy group were matched to those in the no radiotherapy group with a matching ratio of 1:1. After propensity-score matching (PSM), additional competing risk regression analyses were performed to calculate the efficacy of radiotherapy to SPMs in the PSM-adjusted population. In addition, the Fine and Gray model was utilized in the primary cohorts, and stratified analyses were performed based on surgery. This study includes a total of 2,831,789 eligible patients with tumors diagnosed from 2004 to 2015 in the SEER 18 database, amongst whom 100,194 (3.5%) patients developed SPMs. We observe higher risks of SPMs associated with radiotherapy in several types of tumors in the PSM-adjusted populations (small bowel adenocarcinoma, small cell lung carcinoma, prostate adenocarcinoma, urinary bladder transitional cell carcinoma, invasive ductal breast carcinoma, invasive lobular breast carcinoma, and Hodgkin lymphoma). The results in the PSM-adjusted populations were consistent with outcomes in the multivariable competing risk models. Meanwhile, in subgroup analyses stratified by surgery, some other types of tumor (except for those with positive results in the PSM-adjusted cohorts) with radiotherapy were also associated with a higher prevalence of SPMs in the subgroups of surgical treatment (pancreatic adenocarcinoma, rectal adenocarcinoma, lung adenocarcinoma and follicular thyroid carcinoma in the surgery subgroups). The impact of radiotherapy on the incidence of secondary malignancies is distinct in different types of cancer. These findings merit further investigation and may ultimately impact treatment decision-making for tumor management.

Proton therapy for thoracic malignancies: a review of oncologic outcomes

Introduction: Radiotherapy is an integral component in the treatment of the majority of thoracic malignancies. By taking advantage of the steep dose fall-off characteristic of protons combined with modern optimization and delivery techniques, proton beam therapy (PBT) has emerged as a potential tool to improve oncologic outcomes while reducing toxicities from treatment.Areas covered: We review the physical properties and treatment techniques that form the basis of PBT as applicable for thoracic malignancies, including a brief discussion on the recent advances that show promise to enhance treatment planning and delivery. The dosimetric advantages and clinical outcomes of PBT are critically reviewed for each of the major thoracic malignancies, including lung cancer, esophageal cancer, mesothelioma, thymic cancer, and primary mediastinal lymphoma.Expert opinion: Despite clear dosimetric benefits with PBT in thoracic radiotherapy, the improvement in clinical outcomes remains to be seen. Nevertheless, with the incorporation of newer techniques, PBT remains a promising modality and ongoing randomized studies will clarify its role to determine which patients with thoracic malignancies receive the most benefit. Re-irradiation, advanced disease requiring high cardio-pulmonary irradiation volume and younger patients will likely derive maximum benefit with modern PBT.

Proton Reirradiation: Expert Recommendations for Reducing Toxicities and Offering New Chances of Cure in Patients With Challenging Recurrence Malignancies

Local and regional recurrences are common following an initial course of radiotherapy, yet management of these recurrences remains a challenge. Reirradiation may be an optimal treatment approach for providing durable tumor control and even offering select patients with locoregional recurrences or new primary tumors a chance of cure, but photon reirradiation can be associated with considerable risks of high grade acute and late toxicities. The high conformality and lack of exit dose with proton therapy offer significant advantages for reirradiation. By decreasing dose to adjacent normal tissues, proton therapy can more safely deliver definitive instead of palliative doses of reirradiation, more safely dose escalate reirradiation treatment, and more safely allow for concurrent systemic therapy in the reirradiation setting. In this case-based analysis, renowned experts in the fields of proton therapy and of reirradiation present cases for which they recently employed proton reirradiation. This manuscript focuses on case studies in patients with lung cancer, head and neck malignancies, and pelvic malignancies. Considerations for when to deliver proton therapy in the reirradiation setting and the pros and cons of proton therapy are discussed, and the existing literature supporting the use of proton reirradiation for these disease sites is assessed.

Pattern-of-failure and salvage treatment analysis after chemoradiotherapy for inoperable stage III non-small cell lung cancer

Background

Loco-regional and distant failure are common in inoperable stage III non small-cell lung cancer (NSCLC) after chemoradiotherapy (CRT). However, there is limited real-world data on failure pattern, patient prognosis and salvage options.

Methods

We analysed 99 consecutive patients with inoperable stage III NSCLC treated with CRT between 2011 and 2016. Follow up CT scans from date of the first-site failure were matched with the delivered radiation treatment plans. Intra-thoracic loco-regional relapse was defined as in-field (IFR) vs. out-of-field recurrence (OFR) [in- vs. outside 50Gy isodose line in the involved lung], respectively. Extracranial distant (DMs) and brain metastases (BMs) as first site of recurrence were also evaluated. Using the Kaplan-Meier method, impact of salvage surgery (sS), radiotherapy (sRT), chemotherapy (sCT) and immunotherapy (sIO) on patient survival was assessed.

Results

Median follow-up was 60.0 months. Median PFS from the end of CRT for the entire cohort was 7.5 (95% CI: 6.0–9.0 months) months. Twenty-six (26%) and 25 (25%) patients developed IFR and OFR. Median time to diagnosis of IFR and OFR was 7.2 and 6.2 months. In the entire cohort, onset of IFR and OFR did not influence patient outcome. However, in 73 (74%) patients who survived longer than 12 months after initial diagnosis, IFR was a significant negative prognostic factor with a median survival of 19.3 vs 40.0 months (p < 0.001). No patients with IFR underwent sS and/or sRT. 18 (70%) and 5 (19%) patients with IFR underwent sCT and sIO. Three (12%) patients with OFR underwent sS and are still alive with 3-year survival rate of 100%. 5 (20%) patients with OFR underwent sRT with a median survival of 71.2 vs 19.1 months (p = 0.014). Four (16%) patients with OFR received sIO with a numerical survival benefit (64.6 vs. 26.4 months, p = 0.222).

DMs and BMs were detected in 27 (27%) and 16 (16%) patients after median time of 5.8 and 5.13 months. Both had no impact on patient outcome in the entire cohort. However, patients with more than three BMs showed significantly poor OS (9.3 vs 26.0 months; p = 0.012).

Conclusions

After completion of CRT, IFR was a negative prognostic factor in those patients, who survived longer than 12 months after initial diagnosis. Patients with OFR benefit significantly from salvage local treatment. Patients with more than three BMs as first site of failure had a significantly inferior outcome.

Challenges in Re-Irradiation in the Thorax: Managing Patients with Locally Recurrent Non-Small Cell Lung Cancer

Treatment of locally recurrent non-small lung cancer (NSCLC) after definitive chemoradiation therapy is challenging as patients are often inoperable and systemic therapy alone frequently results in suboptimal outcomes. Re-irradiation of NSCLC may be the best strategy for treating locoregional failures with the goal of durable long-term control and potentially cure. Repeat irradiation is technically challenging for fear of life-threatening toxicities to previously irradiated organs at risk while also delivering definitive doses of radiation to recurrent disease. No standard guidelines exist with regards to re-irradiation technique and re-treatment dose constraints to organs at risks. We herein describe a case of locoregional recurrence after definitive chemoradiation therapy for NSCLC with expert opinions for subsequent management. As described and guided by our experts, we review the various techniques for repeat radiation therapy, treatment planning goals, and reported toxicities and outcomes in the re-irradiation setting.

Prognostic factors and outcome of reirradiation for locally recurrent small cell lung cancer-a multicenter study

Background

The prognosis of patients with recurrent small cell lung cancer (SCLC) remains poor and treatment options are limited. We performed a multi-institution retrospective cohort study to evaluate the outcome of thoracic reirradiation, identify prognostic factors and assess treatment-related toxicity.

Methods

Data of 33 patients re-irradiated for recurrent SCLC at 4 international university hospitals, were analysed. Overall survival (OS) acute and late toxicities were evaluated and prognostic factors for reirradiation were identified.

Results

Reirradiation (Re-RT) was performed at a median interval time of 24 months after the first thoracic radiotherapy series. Median survival after reirradiation was 7 months (range, 1-54 months). The Re-RT dose in EQD2 ranged from 20 to 87.50 Gy with a median of 32.50 Gy. The 1- and 2-year OS were 33% and 17%, respectively. Patients with a good performance status (KPS >70%), absence of extrathoracic disease, reirradiation dose (EQD2) of >40 Gy and a cumulative dose of first plus second series of radiotherapy (EQD2) >90 Gy were associated with improved OS. Acute pulmonary Grade 1-2 toxicity from re-irradiation was recorded in 11 patients (33%) and grade 3 acute toxicity was encountered 1 patient (3%).

Conclusions

Reirradiation for locoregionally recurrent SCLC is safe and shows promising outcomes. Patients reirradiated with doses >40 Gy experienced more favourable survival rates. In contrast, patients with a poor performance status or extrathoracic disease have a poor prognosis and Re-RT should be considered only for symptom control in this group.

Photons or protons for reirradiation in (non-)small cell lung cancer: Results of the multicentric ROCOCO in silico study

OBJECTIVE

Locally recurrent disease is of increasing concern in (non-)small cell lung cancer [(N)SCLC] patients. Local reirradiation with photons or particles may be of benefit to these patients. In this multicentre in silico trial performed within the Radiation Oncology Collaborative Comparison (ROCOCO) consortium, the doses to the target volumes and organs at risk (OARs) were compared when using several photon and proton techniques in patients with recurrent localised lung cancer scheduled to undergo reirradiation.

METHODS

24 consecutive patients with a second primary (N)SCLC or recurrent disease after curative-intent, standard fractionated radio(chemo)therapy were included in this study. The target volumes and OARs were centrally contoured and distributed to the participating ROCOCO sites. Remaining doses to the OARs were calculated on an individual patient's basis. Treatment planning was performed by the participating site using the clinical treatment planning system and associated beam characteristics.

RESULTS

Treatment plans for all modalities (five photon and two proton plans per patient) were available for 22 patients (N = 154 plans). 3D-conformal photon therapy and double-scattered proton therapy delivered significantly lower doses to the target volumes. The highly conformal techniques, i.e., intensity modulated radiation therapy (IMRT), volumetric modulated arc therapy (VMAT), CyberKnife, TomoTherapy and intensity-modulated proton therapy (IMPT), reached the highest doses in the target volumes. Of these, IMPT was able to statistically significantly decrease the radiation doses to the OARs.

CONCLUSION

Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. They, however, significantly differ in the dose deposited in the OARs. The therapeutic options, i.e., reirradiation or systemic therapy, need to be carefully weighed and discussed with the patients.

ADVANCES IN KNOWLEDGE

Highly conformal photon and proton beam techniques enable high-dose reirradiation of the target volume. In light of the abilities of the various highly conformal techniques to spare specific OARs, the therapeutic options need to be carefully weighed and patients included in the decision-making process.

Early Detection of Recurrence in Patients With Locally Advanced Non-Small-Cell Lung Cancer via Circulating Tumor Cell Analysis

BACKGROUND

Assays to identify circulating tumor cells (CTCs) might allow for noninvasive and sequential monitoring of lung cancer. We investigated whether serial CTC analysis could complement conventional imaging for detecting recurrences after treatment in patients with locally advanced non-small-cell lung cancer (LA-NSCLC).

PATIENTS AND METHODS

Patients with LA-NSCLC (stage II-III) who definitively received concurrent chemoradiation were prospectively enrolled, with CTCs from peripheral blood samples identified using an adenoviral probe that detects elevated telomerase activity present in nearly all lung cancer cells. A "detectable" CTC level was defined as 1.3 green flourescent protein-positive cells per milliliter of collected blood. Samples were obtained before, during (at weeks 2, 4, and 6), and after treatment (post-radiation therapy [RT]; at months 1, 3, 6, 12, 18, and 24).

RESULTS

Forty-eight patients were enrolled. At a median follow-up of 10.9 months, 22 (46%) patients had disease recurrence at a median time of 7.6 months post-RT (range, 1.3-32.0 months). Of the 20 of 22 patients for whom post-RT samples were obtained, 15 (75%) had an increase in CTC counts post-RT. In 10 of these 15 patients, CTCs were undetectable on initial post-RT draw but were then detected again before radiographic detection of recurrence, with a median lead time of 6.2 months and mean lead time of 6.1 months (range, 0.1-12.0 months) between CTC count increase and radiographic evidence of recurrence. One patient with an early recurrence (4.7 months) had persistently elevated detectable CTC levels during and after treatment.

CONCLUSION

These results indicate that longitudinal CTC monitoring in patients with LA-NSCLC treated with chemoradiation is feasible, and that detectable CTC levels in many patients meaningfully precede radiologic evidence of disease recurrence.

The Special Medical Physics Consult Process for Reirradiation Patients

Purpose

To present a systematic approach to the reirradiation special medical physics consult (ReRT-SMPC) process.

Materials and Methods

An in-house reirradiation committee of physicians and physicists was formed to develop a streamlined and well-documented approach to ReRT-SMPCs. Dosimetric goals and considerations for tissue repair were generated by the committee with input from the literature, clinical trial guidelines, and physician experience. Procedural workflow was also defined.

Results

The total number of ReRT-SMPCs performed in our department in 2018 was 401, corresponding to 369 unique patients and 16% of the total number of patients receiving external beam radiation in our department that year. This constituted a large increase over the 183 ReRT-SMPCs performed in 2017. We have found that a standardized ReRT-SMPC workflow helps to safeguard patients, documents the clinical decision-making process for medical and legal purposes, and facilitates the peer-review process. The data being collected from each consult along with toxicity and outcomes data can be used to help inform future re-treatment guidelines.

Conclusions

As the number of patients returning for additional courses of radiation continues to increase, a uniform method for the ReRT-SMPC workflow and analysis is a powerful tool for ensuring patient safety, understanding and predicting treatment toxicity, and refining reirradiation dosimetric limits.

Clinical Outcomes of Patients With Recurrent Lung Cancer Reirradiated With Proton Therapy on the Proton Collaborative Group and University of Florida Proton Therapy Institute Prospective Registry Studies

PURPOSE

We sought to assess clinical outcomes and toxicities of patients with recurrent lung cancer reirradiated with proton beam therapy (PBT) who were enrolled in 2 prospective registry trials.

METHODS AND MATERIALS

Seventy-nine consecutive patients were reirradiated with PBT at 8 institutions. Conventionally fractionated radiation therapy was used to treat the previous lung cancer in 68% of patients (median equivalent dose in 2 Gy fractions [EQD₂], 60.2 Gy) and hypofractionated/stereotactic body radiation therapy in 32% (median EQD₂, 83.3 Gy). Nine patients (11%) received ≥2 courses of thoracic irradiation before PBT. Eastern Cooperative Oncology Group (ECOG) performance status was 2 to 3 in 13%. Median time from prior radiation therapy to PBT was 19.9 months. PBT was delivered with conventional fractionation in 58% (median EQD₂, 60 Gy), hyperfractionation in 3% (median EQD₂, 62.7 Gy), and hypofractionation in 39% (median EQD₂, 60.4 Gy). Twenty-four patients (30%) received chemotherapy concurrently with PBT.

RESULTS

All patients completed PBT as planned. At a median follow-up of 10.7 months after PBT, median overall survival (OS) and progression-free survival (PFS) were 15.2 months and 10.5 months, respectively. Acute and late grade 3 toxicities occurred in 6% and 1%, respectively. Three patients died after PBT from possible radiation toxicity. On multivariate analysis, ECOG performance status ≤1 was associated with OS (hazard ratio, 0.35; 95% confidence interval, 0.15-0.80; P = .014) and PFS (hazard ratio, 0.32; 95% confidence interval, 0.14-0.73; P = .007).

CONCLUSIONS

This is the largest series to date of PBT reirradiation for recurrent lung cancer and indicates that reirradiation with PBT is well tolerated with acceptable toxicity and encouraging efficacy. ECOG performance status was associated with OS and PFS.

Advances in proton therapy in lung cancer

Lung cancer remains the leading cause of cancer deaths in the United States (US) and worldwide. Radiation therapy is a mainstay in the treatment of locally advanced non-small cell lung cancer (NSCLC) and serves as an excellent alternative for early stage patients who are medically inoperable or who decline surgery. Proton therapy has been shown to offer a significant dosimetric advantage in NSCLC patients over photon therapy, with a decrease in dose to vital organs at risk (OARs) including the heart, lungs and esophagus. This in turn, can lead to a decrease in acute and late toxicities in a population already predisposed to lung and cardiac injury. Here, we present a review on proton treatment techniques, studies, clinical outcomes and toxicities associated with treating both early stage and locally advanced NSCLC.