Stereotactic Ablative Radiation Therapy for Pulmonary Metastases: Histology, Dose, and Indication Matter

Systematic review of the efficacy of stereotactic ablative radiotherapy for oligoprogressive disease in metastatic cancer

BACKGROUND

Stereotactic Ablative Radiotherapy (SABR) for the treatment of oligometastatic disease can improve survival and delay the requirement for systemic therapy. The benefits of SABR in oligoprogressive disease are less well-defined. Here, we evaluate the available evidence investigating the efficacy of SABR in the treatment of oligoprogressive disease.

METHODS

A systematic review was carried out following PRISMA guidelines. Medline and Embase databases were searched using the terms "stereotactic radiotherapy" OR "SABR" OR "Stereotactic Ablative Body Radiotherapy" OR "SBRT" OR "SRT" AND "oligoprogression" in May 2022, June 2023, and February 2024. Studies were excluded where: SABR was used as a radical treatment, a specific oligoprogressive cohort could not be identified, publication was as a conference abstract or where fewer than 10 patients were recruited. Studies treating only brain metastases were also excluded. The site of primary tumour, oligoprogressive sites, rates of overall survival (OS), progression free survival (PFS), local control (LC) and time to next systemic therapy were collected.

RESULTS

Thirty-three full text studies were included. These consisted of single centre and multi-institutional observational studies, case series and phase II trials. Twenty-two studies were related to a specific tumour type: 12 urological cancer (9 prostate, 3 renal cancer), 6 non-small cell lung cancer, 2 colorectal cancer, 2 breast cancer and 11 were studies covering multiple tumour sites (5 studies involving SABR to a single organ and 6 studies involving SABR to multi-organ). Median PFS was >6 months in patients with oligoprogressive prostate, non-small cell lung cancer and renal cancer patients.

CONCLUSIONS

SABR appears to have clinical benefit in oligoprogresssive prostate, lung, and renal patients. However, the optimal management of patients with oligoprogressive disease is still somewhat uncertain due to lack of prospective data. This will hopefully become clearer in the near future with the publication of further randomised trials.

Stereotactic Ablative Radiotherapy for Gynecological Oligometastatic and Oligoprogessive Tumors

Importance

The role of stereotactic ablative radiotherapy (SABR) for gynecologic malignant tumors has yet to be clearly defined despite recent clinical uptake.

Objective

To evaluate the outcomes of SABR in patients with oligometastatic and oligoprogressive gynecologic cancers.

Design, Setting, and Participants

In this retrospective pooled analysis, patients with oligometastatic and oligoprogressive gynecologic cancers receiving SABR at 5 institutions from Canada and the US were studied. Data were collected from January 2011 to December 2020, and data were analyzed from January to December 2023.

Exposure

Stereotactic ablative radiotherapy.

Main Outcomes and Measures

Cumulative incidence of local and distant recurrence, chemotherapy-free survival (CFS), and overall survival (OS) probabilities after SABR were calculated using Kaplan-Meier methods. Univariable and multivariable analysis was conducted using Cox regression methods.

Results

A total of 215 patients with 320 lesions meeting criteria were included in the analysis; the median (range) age at primary diagnosis was 59 (23-86) years. The median (range) follow-up from SABR was 18.5 (0.1-124.5) months. The primary site included the endometrium (n = 107), ovary (n = 64), cervix (n = 30), and vulva or vagina (n = 14). Local cumulative incidence of recurrence was 13.7% (95% CI, 9.4-18.9) and 18.5% (95% CI, 13.2-24.5) at 1 and 5 years, respectively. Distant cumulative incidence of recurrence was 48.5% (95% CI, 41.4-55.1) and 73.1% (95% CI, 66.0-79.0) at 1 and 5 years, respectively. OS was 75.7% (95% CI, 69.2-81.1) and 33.1% (95% CI, 25.3-41.1) at 1 and 5 years, respectively. The median CFS was 21.7 months (95% CI, 15.4-29.9). On multivariable analysis, local recurrence was significantly associated with nodal metastasis, lesion size, biologically effective dose, treatment indication, institution, and primary disease type. Distant progression-free survival was associated with nodal targets and lesion size. OS and CFS were significantly associated with lesion size.

Conclusions and Relevance

In this study, SABR appeared to have excellent local control with minimal toxic effects in this large patient group, and certain patients may achieve durable distant control and OS as well. It may be possible to delay time to chemotherapy in select patient subtypes and therefore reduce associated toxic effects. Prospective multicenter trials will be critical to establish which characteristics procure the greatest benefit from SABR use and to define the ideal time to implement SABR with other oncologic treatments.

Intra- and inter-fractional variations of tumors with fiducial markers measured using respiratory-correlated computed tomography images for respiratory gated lung stereotactic body radiation therapy

PURPOSE

This study evaluated the intra- and inter-fractional variation of tumors with fiducial markers (FMs), relative to the tumor-FM distance, to establish how close an FM should be inserted for respiratory-gated stereotactic body radiation therapy (RG-SBRT).

METHODS

Forty-five lung tumors treated with RG-SBRT were enrolled. End-expiratory computed tomography (CT) (CTplan) and four-dimensional-CT (4D-CT) scans were obtained for planning. End-expiratory CT (CTfr) scanning was performed before each fraction. The FMs were divided into two groups based on the median tumor-FM distance in the CTplan (Dp). For the intra-fractional variation, the correlations between the corresponding tumor and FM intra-fractional motions, defined as the centroid coordinates of those in each 0-90% phase, with the 50% phase of 4D-CT as the origin, were calculated in the left-right, anterior-posterior, and superior-inferior directions. Furthermore, the maximum difference in the tumor-FM distance in each phase of 4D-CT scan, based on those in the 50% phase of 4D-CT scan (Dmax), was obtained. Inter-fractional variation was defined as the maximum distance between the tumors in CTplan and CTfr, when the CT scans were fused based on each FM or vertebra.

RESULTS

The median Dp was 26.1 mm. While FM intra-fractional motions were significantly and strongly correlated with the tumor intra-fractional motions in only anterior-posterior and superior-inferior directions for the Dp > 26 mm group, they were significantly and strongly correlated in all directions for the Dp ≤ 26 mm group. In all directions, Dmax values of the Dp ≤ 26 mm group were lower than those of the Dp > 26 mm group. The inter-fractional variations based on the Dp ≤ 26 mm were smaller than those on the Dp > 26 mm and on the vertebra in all directions.

CONCLUSIONS

Regarding intra- and inter-fractional variation, FMs for Dp ≤ 26 mm can increase the accuracy for RG-SBRT.

Radiotherapy in the management of lung oligometastases

In recent years, the development of both medical imaging and new systemic agents (targeted therapy and immunotherapy) have revolutionized the field of oncology, leading to a new entity: oligometastatic disease. Adding local treatment of oligometastases to systemic treatment could lead to prolonged survival with no significant impact on quality of life. Given the high prevalence of lung oligometastases and the new systemic agents coming with increased pulmonary toxicity, this article provides a comprehensive review of the current state-of-art for radiotherapy of lung oligometastases. After reviewing pretreatment workup, the authors define several radiotherapy regimen based on the localization and size of the oligometastases. A comment on the synergistic combination of medical treatment and radiotherapy is also made, projecting on future steps in this specific clinical setting.

Individualized Stereotactic Ablative Radiotherapy for Lung Tumors: The iSABR Phase 2 Nonrandomized Controlled Trial

Importance

Stereotactic ablative radiotherapy (SABR) is used for treating lung tumors but can cause toxic effects, including life-threatening damage to central structures. Retrospective data suggested that small tumors up to 10 cm3 in volume can be well controlled with a biologically effective dose less than 100 Gy.

Objective

To assess whether individualizing lung SABR dose and fractionation by tumor size, location, and histological characteristics may be associated with local tumor control.

Design, Setting, and Participants

This nonrandomized controlled trial (the iSABR trial, so named for individualized SABR) was a phase 2 multicenter trial enrolling participants from November 15, 2011, to December 5, 2018, at academic medical centers in the US and Japan. Data were analyzed from December 9, 2020, to May 10, 2023. Patients were enrolled in 3 groups according to cancer type: initial diagnosis of non-small cell lung cancer (NSCLC) with an American Joint Committee on Cancer 7th edition T1-3N0M0 tumor (group 1), a T1-3N0M0 new primary NSCLC with a history of prior NSCLC or multiple NSCLCs (group 2), or lung metastases from NSCLC or another solid tumor (group 3).

Intervention

Up to 4 tumors were treated with once-daily SABR. The dose ranged from 25 Gy in 1 fraction for peripheral tumors with a volume of 0 to 10 cm3 to 60 Gy in 8 fractions for central tumors with a volume greater than 30 cm3.

Main outcome

Per-group freedom from local recurrence (same-lobe recurrence) at 1 year, with censoring at time of distant recurrence, death, or loss to follow-up.

Results

In total, 217 unique patients (median [IQR] age, 72 [64-80] years; 129 [59%] male; 150 [69%] current or former smokers) were enrolled (some multiple times). There were 240 treatment courses: 79 in group 1, 82 in group 2, and 79 in group 3. A total of 285 tumors (211 [74%] peripheral and 74 [26%] central) were treated. The most common dose was 25 Gy in 1 fraction (158 tumors). The median (range) follow-up period was 33 (2-109) months, and the median overall survival was 59 (95% CI, 49-82) months. Freedom from local recurrence at 1 year was 97% (90% CI, 91%-99%) for group 1, 94% (90% CI, 87%-97%) for group 2, and 96% (90% CI, 89%-98%) for group 3. Freedom from local recurrence at 5 years ranged from 83% to 93% in the 3 groups. The proportion of patients with grade 3 to 5 toxic effects was low, at 5% (including a single patient [1%] with grade 5 toxic effects).

Conclusions and Relevance

The results of this nonrandomized controlled trial suggest that individualized SABR (iSABR) used to treat lung tumors may allow minimization of treatment dose and is associated with excellent local control. Individualized dosing should be considered for use in future trials.

Trial Registration

ClinicalTrials.gov Identifier: NCT01463423.

Colorectal Pulmonary Metastases: Pulmonary Metastasectomy or Stereotactic Radiotherapy?

BACKGROUND

Pulmonary metastasectomy and stereotactic ablative radiotherapy (SABR) are both guideline-recommended treatments for selected patients with oligometastatic colorectal pulmonary metastases. However, there is limited evidence comparing these local treatment modalities in similar patient groups.

METHODS

We retrospectively reviewed records of consecutive patients treated for colorectal pulmonary metastases with surgical metastasectomy or SABR from 2012 to 2019 at two Dutch referral hospitals that had different approaches toward the local treatment of colorectal pulmonary metastases, one preferring surgery, the other preferring SABR. Two comparable patient groups were identified based on tumor and treatment characteristics.

RESULTS

The metastasectomy group comprised 40 patients treated for 69 metastases, and the SABR group had 60 patients who were treated for 90 metastases. Median follow-up was 38 months (IQR: 26-67) in the surgery group and 46 months (IQR: 30-79) in the SABR group. Median OS was 58 months (CI: 20-94) in the metastasectomy group and 70 months (CI: 29-111) in the SABR group (p = 0.23). Five-year local recurrence-free survival (LRFS) was 44% after metastasectomy and 30% after SABR (p = 0.16). Median progression-free survival (PFS) was 15 months (CI: 3-26) in the metastasectomy group and 10 months (CI: 6-13) in the SABR group (p = 0.049). Local recurrence rate was 12.5/7.2% of patients/metastases respectively after metastasectomy and 38.3/31.1% after SABR (p < 0.001). Lower BED Gy10 was correlated with an increased likelihood of recurrence (p = 0.025). Clavien Dindo grade III-V complication rates were 2.5% after metastasectomy and 0% after SABR (p = 0.22).

CONCLUSION

In this retrospective cohort study, pulmonary metastasectomy and SABR had comparable overall survival, local recurrence-free survival, and complication rates, despite patients in the SABR group having a significantly lower progression-free survival and local control rate. These data would support a randomized controlled trial comparing surgery and SABR in operable patients with radically resectable colorectal pulmonary metastases.

Stereotactic Body Radiotherapy for Lung Oligo-metastases: Systematic Review and International Stereotactic Radiosurgery Society Practice Guidelines

PURPOSE

A systematic review of treatment characteristics, outcomes, and treatment-related toxicities of stereotactic body radiation therapy (SBRT) for pulmonary oligometastases served as the basis for development of this International Stereotactic Radiosurgery Society (ISRS) practice guideline.

METHODS

In accordance with PRISMA guidelines, a systematic review was performed of retrospective series with ≥50 patients/lung metastases, prospective trials with ≥25 patients/lung metastases, analyses of specific high-risk situations, and all randomized trials published between 2012 and July 2022 in the MEDLINE or Embase database using the key words "lung oligometastases", "lung metastases", "pulmonary metastases", "pulmonary oligometastases", "stereotactic body radiation therapy (SBRT)" and "stereotactic ablative body radiotherapy (SBRT)". Weighted random effects models were used to calculate pooled outcomes estimates.

RESULTS

Of the 1884 articles screened, 35 analyses (27 retrospective-, 5 prospective, and 3 randomized trials) reporting on treatment of >3600 patients and >4650 metastases were included. The median local control was 90 % (Range: 57-100 %) at 1 year and 79 % (R: 70-96 %) at 5 years. Acute toxicity ≥3 was reported for 0.5 % and late toxicity ≥3 for 1.8 % of patients. A total of 21 practice recommendations covering the areas of staging & patient selection (n = 10), SBRT treatment (n = 10), and follow-up (n = 1) were developed, with agreements rates of 100 %, except for recommendation 13 (83 %).

CONCLUSION

SBRT represents an effective definitive local treatment modality combining high local control rates with low risk of radiation-induced toxicities.

Treatment outcomes of stereotactic body radiation therapy for pulmonary metastasis from sarcoma: a multicenter, retrospective study

PURPOSE

The aim of this study was to evaluate the treatment outcomes and potential dose-response relationship of stereotactic body radiation therapy (SBRT) for pulmonary metastasis of sarcoma.

MATERIALS AND METHODS

A retrospective review of 39 patients and 71 lesions treated with SBRT from two institutions was performed. The patients had oligometastatic or oligoprogressive disease, or were receiving palliation. Doses of 20-60 Gy were delivered in 1-5 fractions. The local control per tumor (LCpT) was evaluated according to the biologically effective dose with an α/β ratio of 10 (BED₁₀) of the prescribed dose (BED₁₀ ≥ 100 Gy vs. BED₁₀ < 100 Gy). Clinical outcomes per patient, including local control per patient (LCpP), pulmonary progression-free rate (PPFR), any progression-free rate (APFR), and overall survival (OS) were investigated.

RESULTS

The median follow-up period was 27.2 months. The 1-, 2-, and 3-year LCpT rates for the entire cohort were 100.0%, 88.3%, and 73.6%, respectively. There was no observed difference in LCpT between the two BED₁₀ groups (p = 0.180). The 3-year LCpP, PPFR, APFR, and OS rates were 78.1%, 22.7%, 12.9%, and 83.7%, respectively. Five (12.8%) patients with oligometastasis had long-term disease-free intervals, with a median survival period of 40.7 months. Factors that were associated with a worse prognosis were oligoprogression (vs. oligometastasis), multiple pulmonary metastases, and simultaneous extrathoracic metastasis.

CONCLUSION

SBRT for pulmonary metastasis of sarcoma is effective. Some selected patients may achieve durable response. Considerations of SBRT indication and disease extent may be needed as they may influence the prognosis.

Toxicity and Efficacy of Multitarget Thoracic Stereotactic Body Radiation Therapy

PURPOSE

With the increasing use of stereotactic body radiation therapy (SBRT) for primary and metastatic cancer, use of multitarget thoracic (MTT) SBRT is rising. Given the limited safety and efficacy data, we report the experience of this strategy from a large academic center.

METHODS AND MATERIALS

Between 2012 and 2021, patients who received SBRT for ≥2 thoracic targets separated by ≤1 year were retrospectively reviewed. The primary endpoint was clinically significant radiation pneumonitis (CSRP) requiring steroids, oxygen, or intubation. Secondary endpoints included local failure (LF), initiation or change of systemic therapy (ICST), progression-free survival, and overall survival. Competing risk analysis was used to evaluate the cumulative incidence of CSRP, LF, and ICST. Univariate and multivariable analyses were performed to look for clinical and dosimetric predictive factors of CSRP and LF.

RESULTS

One hundred ninety patients (481 lesions) were treated with MTT SBRT with a median follow-up of 19.7 months. Indications for SBRT were oligometastases (n = 70; 36.8%), oligoprogression (n = 62; 32.6%), curative intent in patients with primary lung cancer (n = 37; 19.5%), and control of dominant areas of metastatic progression (n = 21; 11.0%). The number of irradiated tumors ranged from 2 to 7 and the majority of SBRT courses were delivered simultaneously (88.2%). Overall, 14 patients (7.4%) had CSRP, with 5 cases requiring oxygen. The cumulative incidence of CSRP at 6 and 12 months was 5.3% and 7.6%, respectively. The cumulative incidence of LF at 2 years was 10.5%. The cumulative incidence of ICST at 2 years was 41.1%. Median progression-free survival was 11.8 months and median overall survival was 51.3 months. On multivariable analysis, a higher lung V35_Gy (hazard ratio, 2.59; P = .02) was a statistically significant predictor of CSRP and colorectal histology predicted for higher LF (hazard ratio, 2.12; P = .02).

CONCLUSIONS

In one of the largest institutional series of MTT SBRT, rates of CSRP and LF were low. Optimizing plans to lower the lung V35_Gy may decrease the risk of CSRP.

Stereotactic Body Radiation Therapy for Pulmonary Metastasis from Colorectal Adenocarcinoma: Biologically Effective Dose 150 Gy is Preferred for Tumour Control

AIMS

To compare the local control rate of pulmonary metastatic lesions in colorectal adenocarcinoma treated with stereotactic body radiation therapy (SBRT) using a biologically effective dose with an α/β ratio of 10 (BED₁₀) of 150 Gy.

MATERIALS AND METHODS

We analysed 231 pulmonary metastatic lesions from colorectal adenocarcinoma treated with SBRT in 135 patients. The patients were referred for the control of oligometastatic or oligoprogressive disease in the lungs. A dose of 40-60 Gy in three to eight fractions was delivered. The local control per tumour (LCpT) by BED₁₀ was evaluated. The local control per patient (LCpP), pulmonary progression-free survival (PPFS), any progression-free survival (APFS) and overall survival were also reported as clinical outcomes.

RESULTS

A significant difference was observed in the LCpT between the BED₁₀ groups (P < 0.001). The 1-, 2- and 3-year LCpT were 38.9%, 25.9% and 25.9% in BED₁₀ < 100 group; 84.1%, 62.6% and 60.4% in 100 ≤ BED₁₀ < 150 Gy group; and 97.3%, 94.9% and 85.2% in BED₁₀ ≥ 150 Gy group, respectively. BED₁₀ ≥ 150 Gy remained significant in the multivariate analysis of LCpT. The 3-year LCpP, PPFS, APFS and overall survival rates were 62.7%, 26.5%, 24.8% and 67.7%, respectively. Oligoprogression (versus oligometastasis), multiple pulmonary nodules and extrapulmonary metastasis were associated with a poor prognosis.

CONCLUSION

A BED₁₀ ≥ 150 Gy may be required to achieve sufficient local control. The indications for SBRT and the extent of metastatic disease should be assessed for proper estimation of the clinical outcomes.

CT radiomic predictors of local relapse after SBRT for lung oligometastases from colorectal cancer: a single institute pilot study

OBJECTIVES

To assess the potential of radiomic features (RFs) extracted from simulation computed tomography (CT) images in discriminating local progression (LP) after stereotactic body radiotherapy (SBRT) in the management of lung oligometastases (LOM) from colorectal cancer (CRC).

MATERIALS AND METHODS

Thirty-eight patients with 70 LOM treated with SBRT were analyzed. The largest LOM was considered as most representative for each patient and was manually delineated by two blinded radiation oncologists. In all, 141 RFs were extracted from both contours according to IBSI (International Biomarker Standardization Initiative) recommendations. Based on the agreement between the two observers, 134/141 RFs were found to be robust against delineation (intraclass correlation coefficient [ICC] > 0.80); independent RFs were then assessed by Spearman correlation coefficients. The association between RFs and LP was assessed with Mann-Whitney test and univariate logistic regression (ULR): the discriminative power of the most informative RF was quantified by receiver-operating characteristics (ROC) analysis through area under curve (AUC).

RESULTS

In all, 15/38 patients presented LP. Median time to progression was 14.6 months (range 2.4-66 months); 5/141 RFs were significantly associated to LP at ULR analysis (p < 0.05); among them, 4 RFs were selected as robust and independent: Statistical_Variance (AUC = 0.75, p = 0.002), Statistical_Range (AUC = 0.72, p = 0.013), Grey Level Size Zone Matrix (GLSZM) _zoneSizeNonUniformity (AUC = 0.70, p = 0.022), Grey Level Dependence Zone Matrix (GLDZM) _zoneDistanceEntropy (AUC = 0.70, p = 0.026). Importantly, the RF with the best performance (Statisical_Variance) is simply representative of density heterogeneity within LOM.

CONCLUSION

Four RFs extracted from planning CT were significantly associated with LP of LOM from CRC treated with SBRT. Results encourage further research on a larger population aiming to define a usable radiomic score combining the most predictive RFs and, possibly, additional clinical features.

Stereotactic body radiation therapy for metastatic lung metastases

Although systemic therapy is standard management for patients with metastatic disease, several recent reports have indicated that an addition of local therapies including stereotactic body radiation therapy (SBRT) for patients with oligometastatic disease (OMD) could improve survival. The lung is the most common site of distant metastasis from many solid tumors, and the strategy of SBRT, such as dose-fraction schedules, timing, etc., would be different depending on the type of primary tumor, location, and patterns of OMD. This review describes the role of SBRT with curative-intent for patients with pulmonary OMD for each of these variables. First, differences according to the type of primary tumor, for which many studies suggest that SBRT-mediated local control (LC) for patients with pulmonary OMD from colorectal cancer (CRC) is less successful than for those from non-CRC tumors. In addition, higher dose-fraction schedules seemed to correlate with higher LC; hence, different SBRT treatment strategies may be needed for patients with pulmonary OMD from CRC relative to other tumors. Second, differences according to location, where the safety of SBRT for peripheral pulmonary tumors has been relatively well established, but safety for central pulmonary tumors including pulmonary OMD is still considered controversial. To determine the optimal dose-fraction schedules, further data from prospective studies are still needed. Third, differences according to the patterns of OMD, the number of metastases and the timing of SBRT whereby 1–5 lesions in most patients and patients with synchronous or metachronous OMD are considered good candidates for SBRT. We conclude that there are still several problems in defining suitable indications for local therapy including SBRT, and that further prospective studies are required to resolve these issues.

Outcome of lung oligometastatic patients treated with stereotactic body irradiation

Purpose

The oligometastatic stage is an intermediate stage of cancer between the localized stage and polymetastatic stage. The prognosis of patients in this stage also appears to be intermediate. Lung stereotactic body radiotherapy is a possible tool for treating oligometastatic lung sites. The objective of our study was to evaluate the clinical outcomes in terms of local control, progression-free survival, overall survival, and toxicity of SBRT in oligometastatic patients with lung metastases from any solid primary tumor.

Materials and methods

Clinical records of consecutive lung oligometastatic patients treated between January 2010 and December 2020 for lung SBRT at 60 Gy in 3- or 8-fraction schedules and a controlled primary tumor were retrospectively analyzed.

Results

After a median follow-up of 20.3 months, local failure occurred for 14 lesions, 57 patients experienced lung progression, and 64 patients experienced disease progression. Overall survival rates at 1 and 2 years were 85.6 and 69.7%, respectively. Fifty-two patients experienced radiation pneumonitis, but only 2 patients were symptomatic and presented grade 2 late pneumonitis. No grade 3-4 toxicity was observed. ECOG 0 was the only prognostic factor for overall survival (HR = 3.5; 95% CI 3.2-3.8; p < 0.01).

Conclusion

SBRT with a 60-Gy schedule in 8 fractions is an effective and well-tolerated treatment for patients with lung oligometastases from any solid primary tumor.

High Yield of Chest X-ray in the Follow-Up of Colorectal Cancer

Purpose: Worldwide, colorectal carcinoma (CRC) has a high incidence and a substantial cancer-related mortality. The recurrence risk is 30–50% and lung metastases are common. Treatment of lung metastases with stereotactic ablative radiotherapy (SABR) or metastasectomy may increase survival. The best modality for thoracic screening in the follow-up, however, remains controversial. In this study, we aimed to unravel the additional value of routine chest X-ray (CXR) for detecting lung metastases during the follow-up of CRC patients treated with curative surgery. Methods: Between 2013 and 2017, 668 CRC patients were treated with curative intent, of whom 633 patients were included in follow-up, which consisted of CXR, serum Carcino-Embryonic Antigen (CEA) and ultrasound of the liver. Patients who developed lung metastases, diagnosed with CXR and characterised by a normal concomitant serum CEA level, were identified. Number, size and treatment of lung metastases were described. Results: Thirty-four (5.4%) patients developed lung metastases. Seventeen (50%) were detected by CXR without pathological CEA levels. Eleven (65%) of these patients were treated with curative intent, whereas 21% of patients with lung metastases and elevated CEA levels were treated with curative intent (p = 0.049). Higher numbers of lung metastases were associated with a lower chance of curative treatment. Conclusions: More than 50% of patients with lung metastases on CXR in the follow-up would not have been detected with CEA-triggered imaging only. In addition, patients with colorectal lung metastases without elevated CEA levels were often suitable for curative treatment and, therefore, CXR seems to have additional value within the follow-up of CRC.

Treatment outcomes of stereotactic ablative body radiotherapy on oligometastases from colorectal cancer: early results of a single institution service evaluation

Objective

Stereotactic ablative radiotherapy (SABR) has been suggested to be an effective non-invasive ablative therapy for oligometastases originated from colorectal cancer (CRC). This study aimed to report CRC oligometastases SABR treatment outcomes in terms of overall survival (OS), progression-free survival (PFS) and post-treatment toxicities.

Methods

Treatment records of patients with CRC metachronous oligometastases who underwent SABR at a single institution between February 2015 and December 2018 were retrospectively reviewed. OS and PFS were calculated using Kaplan-Meier statistics and post-RT toxicity data was scored following CTCAE v. 4.0. Analysis of prognostic factors on OS and PFS was performed based on site of primary cancer, types of treatment to primary cancer, number of oligometastases, SABR treatment sites, intervals between treatment to primary cancer and SABR to oligometastases, biological equivalent dose, cumulative gross tumour volume and planning target volume.

Results

75 patients with 86 CRC metachronous oligometastases (including liver, lung, lymph nodes and bone) were included. The median age was 65.5 years (range 42.5-87.2) with a median follow-up of 23.8 months (range 3.1-46.5). The estimated median PFS was 14.6 months (95% CI 9.6-19.6). and estimated median OS was 33.3 months (95% CI 22.9-43.7). Majority of patients tolerated SABR well with the most common acute side-effects of Grade 1 fatigue. No Grade 3 or higher toxicities were reported at any time points.Only SABR treatment sites (p = 0.03) and cumulative volumes of planning target volume (p = 0.02) were found to be statistically significant independent predictors of PFS and OS respectively.

Conclusion

This study showed modest PFS, OS, and post-treatment toxicity outcomes on SABR to metachronous oligometastases from CRC. It has highlighted that cumulative tumour volume may be a stronger prognostic factor of OS comparing to the number of metastases.

Advances in knowledge

There are limited data published on the efficacy and post-treatment toxicity of CRC oligometastases SABR with adequate length of follow-up. Our retrospective study suggests that cumulative tumour volume may be a stronger prognostic factor of OS comparing to the number of oligometastases.

Single-fraction stereotactic ablative body radiation therapy for primary and metastasic lung tumor: A new paradigm?

Stereotactic ablative body radiotherapy (SABR) is an effective technique comparable to surgery in terms of local control and efficacy in early stages of non-small cell lung cancer (NSCLC) and pulmonary metastasis. Several fractionation schemes have proven to be safe and effective, including the single fraction (SF) scheme. SF is an option cost-effectiveness, more convenience and comfortable for the patient and flexible in terms of its management combined with systemic treatments. The outbreak of the severe acute respiratory syndrome coronavirus 2 pandemic has driven this not new but underutilized paradigm, recommending this option to minimize patients’ visits to hospital. SF SABR already has a long experience, strong evidence and sufficient maturity to reliably evaluate outcomes in peripheral primary NSCLC and there are promising outcomes in pulmonary metastases, making it a valid treatment option; although its use in central locations, synchronous and recurrencies tumors requires more prospective safety and efficacy studies. The SABR radiobiology study, together with the combination with systemic therapies, (targeted therapies and immunotherapy) is a direction of research in both advanced disease and early stages whose future includes SF.

Suitability of Metastatic Lung Tumors for Stereotactic Body Radiotherapy

We investigated factors influencing local control of lung metastases treated with stereotactic body radiotherapy (SBRT) and determined the type of lesions for which SBRT is more suitable. Ninety-six patients and 196 tumors were included. Median follow-up duration was 32.0 months (range 4.7-95.8). The two-year local recurrence rate was 15.2% (95% confidence interval: 10.2-21.3). Multivariate analysis revealed biological effective dose, ultracentral tumor location, reirradiation, and prior chemotherapy as significant factors. SBRT is suitable for lung metastases, especially for peripheral tumors and those located in the inner lung parenchyma. For ultracentral lesions and recurrent lesions after SBRT, metastasectomy is recommended.

Stereotactic Body Radiotherapy for Patients with Lung Oligometastatic Disease: A Five-Year Systematic Review

For several years, oligometastatic disease has represented an intermediate state between localized disease accessible to local treatment and multimetastatic disease requiring systemic therapy. The lung represents one of the most common metastatic locations. Stereotactic body radiation therapy (SBRT) appears to be the treatment of choice for these patients. There are few data defining the place of radiotherapy and reporting outcome after SBRT in lung metastases. This 5-year review aimed to determine areas of SBRT usefulness and methods for the management of pulmonary metastasis in oligometastatic patients. A search for articles on PubMed allowed selection of the most relevant studies. Eighteen articles were selected according to pre-established criteria for this purpose. The analysis concludes that SBRT is an effective and safe treatment in selected patients when the disease remains localized from one to three organs.

Current Evidence for Stereotactic Body Radiotherapy in Lung Metastases

Lung metastases are the second most common malignant neoplasms of the lung. It is estimated that 20–54% of cancer patients have lung metastases at some point during their disease course, and at least 50% of cancer-related deaths occur at this stage. Lung metastases are widely accepted to be oligometastatic when five lesions or less occur separately in up to three organs. Stereotactic body radiation therapy (SBRT) is a noninvasive, safe, and effective treatment for metastatic lung disease in carefully selected patients. There is no current consensus on the ideal dose and fractionation for SBRT in lung metastases, and it is the subject of study in ongoing clinical trials, which examines different locations in the lung (central and peripheral). This review discusses current indications, fractionations, challenges, and technical requirements for lung SBRT.

12 × 6 Gy stereotactic radiotherapy for lung tumors. Is there a difference in response between lung metastases and primary bronchial carcinoma?

PURPOSE

The aim of this study was to evaluate the safety and long-term tumor control after stereotactic radiotherapy (SRT) with 12 × 6 Gy of patients with primary bronchial carcinoma (BC) or with pulmonary metastases (MET) of various solid tumors. Local progression-free survival (LPFS), progression-free survival (PFS), overall survival (OS), and prognostic factors were compared.

METHODS

Between May 2012 and January 2020, 168 patients with 206 pulmonary lesions (170 MET and 36 primary BC) were treated with 12 × 6 Gy (BED₁₀ 116 Gy). The irradiated pulmonary MET were from the following cancers: 47 (27.6%) head and neck, 37 (21.8%) rectum or colon, 30 (17.6%) bronchial, 13 (7.6%) malignant melanoma, 9 (5.3%) esophageal, 9 (5.3%) sarcoma, and 25 (14.8%) other.

RESULTS

The median follow-up was 16.26 months (range: 0.46-89.34) for BC and 19.18 months (0.89-91.11) for MET. Survival rates at 3 years were: OS 43% for BC and 35% for MET; LPFS BC 96% and MET 85%; PFS BC 35% and MET 29%. The most frequently observed grade 3 adverse events (AEs) were pneumonitis (5.9% BC, 4.8% MET), pulmonary fibrosis (2.9% BC, 4% MET), and pulmonary embolism (2.9% BC, 0.8% MET). The favorable prognostic effects on overall survival of patients with MET were female gender (log-rank: p < 0.001), no systemic progression (log-rank; p = 0.048, multivariate COX regression p = 0.039), and malignant melanoma histology (log-rank; p = 0.015, multivariate COX regression p = 0.020). For patients with BC, it was tumor location within the lower lobe (vs. upper lobe, log-rank p = 0.027). LPFS of patients with metastatic disease was beneficially influenced by female gender (log-rank: p = 0.049).

CONCLUSION

The treatment concept of 12 × 6 Gy is associated with 96% local progression-free survival for BC and 85% for pulmonary metastases after 3 years. There was no difference in response after SRT of primary lung carcinoma or pulmonary metastases.

Outcomes of extra-cranial stereotactic body radiotherapy for metastatic breast cancer: Treatment indication matters

BACKGROUND AND PURPOSE

To summarize the clinical outcomes of stereotactic body radiotherapy (SBRT) for metastatic breast cancer (mBC) from a large institution.

MATERIALS AND METHODS

Patients with mBC who received extra-cranial SBRT to metastatic lesions from 2011 to 2017 were identified. Treatment indications were: oligometastases, oligoprogression, and local control of dominant tumor (CDT). Endpoints included overall survival (OS), progression-free survival (PFS), local control (LC) and cumulative incidence of starting/changing chemo or hormonal therapy (SCT). Univariate and multivariate analyses were used to identify predictive factors.

RESULTS

We analyzed 120 patients (193 treated metastatic lesions) with a median follow up of 15.25 months. 1-and 2-year LC rates were 89% and 86.6%, respectively. 1-and 2-year OS rates were 83.5% and 70%, respectively, with treatment indication and molecular subtype being the predictive factors on MVA. 1-year OS was 91.0%, 78.5% and 63.9% for oligometastases, oligoprogression and CDT, respectively (p = 0.003). The worst OS was seen in basal subtype with 1-and 2-year OS rates of 59.2% and 39.5% (p = 0.01). Treatment indication was found to be predictive for PFS and lower rates of SCT on MVA. 1-and 2-year PFS rates were 45% and 32%, respectively. The 1-year PFS for oligometastases, oligoprogression, and CDT was 66%, 19.6%, and 14.3%, respectively (p < 0.001). The cumulative incidence of SCT at 1-year was 12% for oligometastases, 39.7% for oligoprogression and 53.3% for CDT (p < 0.001).

CONCLUSION

Patients treated for oligometastases have better OS and PFS than those treated for oligoprogression or CDT. SBRT may delay SCT in mBC patients, particularly those with oligometastases. SBRT provided an excellent LC in mBC patients.

Increased Radiosensitivity of Solid Tumors Harboring ATM and BRCA1/2 Mutations

Purpose

Preclinical data indicate that response to radiotherapy (RT) depends on DNA damage repair. In this study, we investigated the role of mutations in genes related to DNA damage repair in treatment outcome after RT.

Materials and Methods

Patients with solid tumor who participated in next generation sequencing panel screening using biopsied tumor tissue between October 2013 and February 2019 were reviewed and 97 patients that received RT were included in this study. Best response to RT and the cumulative local recurrence rate (LRR) were compared according to absence or presence of missense, nonsense, and frameshift mutations in ATM and/or BRCA1/2.

Results

Of the 97 patients, five patients harbored mutation only in ATM, 22 in only BRCA1/2, and six in both ATM and BRCA1/2 (ATM^mtBRCA^mt). Propensity score matching was performed to select the control group without mutations (ATM^wtBRCA^wt, n=33). In total, 90 RT-treated target lesions were evaluated in 66 patients. Highest objective response rate of 80% was observed in ATM^mtBRCA^mt lesions (p=0.007), which was mostly durable. Furthermore, the cumulative 1-year LRR was the lowest in ATM^mtBRCA^mt lesions and the highest in ATM^wtBRCA^wt lesions (0% vs. 47.9%, p=0.008). RT-associated toxicities were observed in 10 treatments with no significant difference among the subgroups (p=0.680).

Conclusion

Tumors with ATM and BRCA1/2 mutations exhibited superior tumor response and local control after RT compared to tumors without these mutations. The results are hypothesis generating and suggest the need for integrating the tumor mutation profile of DNA repair genes during treatment planning.

Multi-Institutional Retrospective Analysis of the Outcomes of Proton Beam Therapy for Patients With 1 to 3 Pulmonary Oligometastases From Various Primary Cancers

Purpose

Our purpose was to evaluate the efficacy of proton beam therapy (PBT) in patients with 1 to 3 pulmonary oligometastases from various primary cancers in Japan.

Methods and Materials

This multi-institutional retrospective survey included 118 patients with 141 metastatic lung tumors from miscellaneous primary cancers, across 6 Japanese institutions, and involved the analyses of local progression-free rate (LPF), distant progression-free rate, progression-free survival rate, cause-specific survival rate, and overall survival rate (OS). Treatment-induced adverse effects of grade ≥2 were evaluated according to the Common Terminology Criteria for Adverse Events (version 4.0). Cox proportional hazards regression models were used in univariable analysis and multivariable analysis (MVA) for the identification of the prognostic factors of LPF and OS.

Results

The median follow-up duration from the time of PBT was 25.5 months. The major primary disease sites included colorectal cancer (42.4%), lung cancer (11.9%), head and neck cancer (8.5%), and kidney cancer (8.5%). For years 1, 2, and 3, LPFs were 92.2%, 86.3%, and 78.4%; distant progression-free rates were 59.1%, 44.1%, and 34.0%; progression-free survival rates were 49.6%, 31.7%, and 24.2%; cause-specific survival rates were 83.4%, 72.5%, and 64.8%; and OS rates were 79.0%, 67.8%, and 59.6%, respectively. Eight patients developed acute adverse effects (grade ≥2). Ten patients developed radiation pneumonitis (grade 2) as a late adverse effect. None of the patients developed severe late toxicity (grade ≥3). Colorectal cancer as the primary disease was the only prognostic factor associated with LPF that remained independently significant in the MVAs performed using 3 sets of parameters (hazard ratio [HR], 3.31-4.76 in 3 MVA sets). In the MVA, the significant prognostic factors for OS were performance status (HR, 2.78; 95% confidence interval, 1.01-7.67) and total tumor volume (HR, 1.01; 95% confidence interval, 1.00-1.02).

Conclusions

PBT provides promising outcomes for pulmonary oligometastasis with acceptable toxicities.

Stereotactic body radiotherapy prolongs the progression-free survival and delays the change of systemic therapy regimen in patients with lung oligoprogressive metastatic colorectal cancer

PURPOSE

To analyze the effect of stereotactic body radiotherapy (SBRT) on colorectal cancer (CRC) patients with lung oligoprogression (OP).

METHOD

Patients with lung OP from CRC treated by SBRT at our center were included in this retrospective analysis. The progression-free survival (PFS), change of systemic therapy (CST), local control (LC), and overall survival (OS) were analyzed. Cumulative incidence was used to report CST, and the Kaplan-Meier method was used to evaluate PFS and LC.

RESULTS

A total of 17 patients with 38 lung OP lesions treated by SBRT from October 2012 to December 2018 were involved. All patients had undergone radical resection for primary CRC and administered with standard systemic therapy regimens (seven for the first line and 10 for the second line). Among them, nine (52.9%) had received targeted therapy before SBRT, 14 (82.4%) patients underwent chemotherapy, and 12 received targeted therapy after SBRT. Six patients (35.3%) underwent CST after a median time of 5.2 months (range: 1.7-27.5 months). The median follow-up was 9.9 months, and the 1-year OS rate for all patients was 73.5%. Progression was observed in of 14 of 17 patients (82.4%), and the 6-month PFS for all patients was 25.9%. Univariate analysis indicated that only targeted therapy before SBRT was a beneficial prognostic indicator for 6-month PFS (P = .026) and N-PFS (P = .013). The 1-year LC for all 38 lesions was 77.8%, and during and after SBRT, no grade 3 or higher toxicities were observed.

CONCLUSION

SBRT combined with systemic therapy made partial CRC patients with lung OP avoid the progress within 6 months and delayed the need for CST to 5.2 months, and targeted therapy before SBRT was a positive indicator of PFS.

Outcomes of Stereotactic Body Radiotherapy for Metastatic Colorectal Cancer With Oligometastases, Oligoprogression, or Local Control of Dominant Tumors

AIM

To evaluate the clinical outcomes of metastatic colorectal cancer (mCRC) patients with oligometastases, oligoprogression, or local control of dominant tumors after stereotactic body radiotherapy (SBRT) and establish a nomogram model to predict the prognosis for these patients.

METHODS AND MATERIALS

A cohort of 94 patients with 162 mCRC metastases was treated with SBRT at a single institution. Treatment indications were oligometastases, oligoprogression, and local control of dominant tumors. End points of this study were the outcome in terms of progression-free survival (PFS), overall survival (OS), local progression (LP), and cumulative incidence of starting or changing systemic therapy (SCST). In addition, univariate and multivariable analyses to assess variable associations were performed. The predictive accuracy and discriminative ability of the nomogram were determined by concordance index (C-index) and calibration curve.

RESULTS

Median PFS were 12.6 months, 6.8 months, and 3.7 months for oligometastases, oligoprogression, and local control of dominant tumors, respectively. 0-1 performance status, < 10 ug/L pre-SBRT CEA, and ≤ 2 metastases were significant predictors of higher PFS on multivariate analysis. Median OS were 40.0 months, 26.1 months, and 6.5 months for oligometastases, oligoprogression, and local control of dominant tumors, respectively. In the multivariate analysis of the cohort, the independent factors for survival were indication, performance status, pre-SBRT CEA, and PTV, all of which were selected into the nomogram. The calibration curve for probability of survival showed the good agreement between prediction by nomogram and actual observation. The C-index of the nomogram for predicting survival was 0.848.

CONCLUSIONS

SBRT for metastases derived from colorectal cancer offered favorable survival and symptom palliation without significant complications. The proposed nomogram could provide individual prediction of OS for patients with mCRC after SBRT.

Analyses of the local control of pulmonary Oligometastases after stereotactic body radiotherapy and the impact of local control on survival

Background

Successful local therapy for oligometastases may lead to longer survival. The purpose of this multicentre retrospective study was to investigate factors affecting the local control (LC) of pulmonary oligometastases treated by stereotactic body radiotherapy (SBRT) and to investigate the impact of LC on survival.

Methods

The inclusion criteria included 1 to 5 metastases, the primary lesion and other extrathoracic metastases were controlled before SBRT, and the biological effective dose (BED₁₀) of the SBRT was 75 Gy or more. The Cox proportional hazards model was used for analyses.

Results

Data of 1378 patients with 1547 tumours from 68 institutions were analysed. The median follow-up period was 24.2 months. The one-year, 3-year and 5-year LC rates were 92.1, 81.3 and 78.6%, respectively, and the 1-year, 3-year and 5-year overall survival rates were 90.1, 60.3 and 45.5%, respectively. Multivariate analysis for LC showed that increased maximum tumour diameter (p = 0.011), type A dose calculation algorithm (p = 0.005), shorter overall treatment time of SBRT (p = 0.035) and colorectal primary origin (p < 0.001 excluding oesophagus origin) were significantly associated with a lower LC rate. In the survival analysis, local failure (p < 0.001), worse performance status (1 vs. 0, p = 0.013; 2–3 vs. 0, p < 0.001), oesophageal primary origin (vs. colorectal origin, p = 0.038), squamous cell carcinoma (vs. adenocarcinoma, p = 0.006) and increased maximum tumour diameter (p < 0.001) showed significant relationships with shorter survival.

Conclusions

Several factors of oligometastases and SBRT affected LC. LC of pulmonary oligometastases by SBRT showed a significant survival benefit compared to patients with local failure.

The Reintroduction of Radiotherapy Into the Integrated Management of Kidney Cancer

The incidence of renal cell carcinoma (RCC) has been increasing, with a moderate subgroup of individuals who later develop metastatic disease. Historically, metastatic RCC has been managed with systemic therapy because RCC was believed to be radioresistant. Local therapies, such as stereotactic body radiation therapy, also known as stereotactic ablative radiotherapy, which utilize focused high-dose-rate radiation delivered over a limited number of treatments, have been successful in controlling local disease and, in some cases, extending survival in patients with intracranial and extracranial metastatic RCC. Stereotactic ablative radiotherapy is highly effective in treating intact disease when patients are not surgical candidates. Stereotactic ablative radiotherapy is well tolerated when used in conjunction with systemic therapy such as tyrosine kinase inhibitors and immune checkpoint inhibitors. These successes have prompted investigators to evaluate the efficacy of stereotactic body radiation therapy in novel settings such as neoadjuvant treatment of advanced RCC with tumor thrombus and oligometastatic/oligoprogressive disease states.

Radiotherapy for primary tumor in lung cancer with synchronous metastases: Overview from the past and proposal for the future

The management of metastatic lung cancers, either of the small-cell (SCLC) or the non-small cell (NSCLC) subtype, largely based on systemic treatments so far, has been the subject of breakthrough advances over the past few years, with notably the wide use of immunotherapy changing the landscape of these harmful prognosis diseases. In parallel with this major progress, the increasing use of radiotherapy (RT) for the treatment of the primary thoracic lesion±the distant lesions, may contribute to improving the condition of these metastatic patients, both in terms of progression-free survival (PFS) and overall survival (OS). This review proposes to summarize and explain the findings provided by the different studies published in the last years experiencing RT of the primary tumor in metastatic lung cancers, either associated or not with the local ablative treatment of a low number of distant lesions. It will also expose the respective limits encountered in these studies and, in the light of all these elements, suggests various promising issues and fields of research for the future.

Stereotactic robotic body radiotherapy for patients with oligorecurrent pulmonary metastases

BACKGROUND

Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free- (lung PFS/Di-PFS) and overall survival (OS).

METHODS

Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk- and Cox regression.

RESULTS

Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage.

CONCLUSIONS

SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features.

Surgery versus stereotactic radiotherapy for treatment of pulmonary metastases. A systematic review of literature

It is not clear as to which is the best treatment among surgery and stereotactic radiotherapy (SBRT) for lung oligometastases. A systematic review of literature with a priori selection criteria was conducted on articles on the treatment of pulmonary metastases with surgery or SBRT. Only original articles with a population of patients of more than 50 were selected. After final selection, 61 articles on surgical treatment and 18 on SBRT were included. No difference was encountered in short-term survival between pulmonary metastasectomy and SBRT. In the long-term surgery seems to guarantee better survival rates. Mortality and morbidity after treatment are 0–4.7% and 0–23% for surgery, and 0–2% and 4–31% for SBRT. Surgical metastasectomy remains the treatment of choice for pulmonary oligometastases.

Patients with metastatic cancer with a limited number of deposits may benefit from surgical removal or irradiation of tumor nodules in addiction to chemotherapy. Surgical resection has been demonstrated to improve survival and, in some cases, can be curative. Stereotactic radiotherapy is emerging as a less invasive alternative to surgery, but settings and implications of the two treatments are profoundly different. The two techniques show similar results in the short-term, with lower complications rates for radiotherapy, while in the long-term surgery seems to guarantee higher survival rates.

Outcomes of stereotactic body radiotherapy 60 Gy in 8 fractions when prioritizing organs at risk for central and ultracentral lung tumors

BACKGROUND

For stereotactic body radiotherapy (SBRT) to central (C) and ultracentral (UC) lung tumors, our provincial practice has been to prioritize organs at risk (OARs) constraints by compromising target volume coverage if needed. The objectives are to report the treatment's efficacy and safety.

METHODS

We conducted a retrospective analysis of all provincial patients who underwent SBRT at 60Gy in 8 fractions to C and UC lung tumors, from 2013 to 2017.

RESULTS

Ninety-eight lesions were treated, 57 (58.2%) C and 41 (41.8%) UC. The median follow-up was 22.9 months (range 2.5-64.8 months). The 1- and 3-year local control (LC) was 97.8 and 84.5% respectively, with no differences between C and UC groups (p = 0.662). Fifty-three (54.1%) cases had optimal dose coverage (V60Gy ITV&PTV > 95%), 29 (29.6%) had compromised PTV coverage (V60Gy ITV > 95%/PTV < 95%), and 16 (16.3%) had both compromised ITV and PTV coverage (V60Gy ITV&PTV < 95%). No significant difference in LC was detected at 2 years between the 3 groups (95.6, 91.8 and 90.9%, p = 0.717). There were 3 episodes of grade 3 toxicity in the C group (2 dyspnea, 1 pneumonitis) and 2 in the UC group (1 dyspnea, 1 hemoptysis). There were no gr4/5 toxicities. On multivariable Cox regression analysis, ITV size was found to be a predictor for LC (p = 0.001).

CONCLUSIONS

SBRT at 60Gy in 8 fractions achieves high rates of LC with low risks of significant toxicities, even if target volume coverage is reduced to meet OARs constraints.

Stereotactic ablative radiotherapy and systemic treatments for extracerebral oligometastases, oligorecurrence, oligopersistence and oligoprogression from lung cancer

Background

Stereotactic irradiation (SBRT) is a standard of care for inoperable stage I lung cancer and brain oligometastases from lung cancer but is controversial for extracranial oligometastases. We assessed outcomes of lung cancer patients with extracranial metastases in oligometastatic, oligorecurrent, oligopersistent and oligoprogressive settings (“oligometastatic spectrum”) under strategies using SBRT +/− systemic treatments.

Methods

A retrospective multicentric study of consecutive lung cancer adult patients with 1–5 extracranial metastases treated with SBRT was conducted.

Results

Of 91 patients (99 metastases, median age 63, 64.8% adenocarcinomas, 19.8% molecular alterations), 11% had oligometastases, 49.5% oligorecurrence, 19.8% oligopersistence and 19.8% oligoprogression. Of 36% of patients under systemic treatments at initiation of SBRT, systemic treatment interruption was performed in 58% of them. With median follow up of 15.3 months, crude local control at irradiated metastases was 91%, while median distant progression-free survival (dPFS) and overall survival were 6.3 and 28.4 months (2-year survival 54%). Initial nodal stage and oligometastatic spectrum were prognostic factors for dPFS; age, initial primary stage and oligometastatic spectrum were prognostic factors for survival on multivariate analysis. Patients with oncogene-addicted tumors more frequently had oligoprogressive disease. Repeat ablative irradiations were preformed in 80% of patients who had oligorelapses. Worst acute toxicities consisted of 5.5% and one late toxic death occurred.

Conclusion

The oligometastatic spectrum is a strong prognosticator in patients undergoing SBRT for extracranial metastases. Median survival was over two years but dPFS was about 6 months. Continuation of systemic therapy in oligoprogressive patients should be investigated.

Can thoracic nodes oligometastases be safely treated with image guided hypofractionated radiation therapy?

OBJECTIVE

To evaluate safety and efficacy of image guided-hypofractionated radiation therapy (IG-HRT) in patients with thoracic nodes oligometastases.

METHODS

The present study is a multicenter analysis. Oligometastatic patients, affected by a maximum of five active lesions in three or less different organs, treated with IG-HRT to thoracic nodes metastases between 2012 and 2017 were included in the analysis. Primary end point was local control (LC), secondary end points were overall survival (OS), progression-free survival, acute and late toxicity. Univariate and multivariate analysis were performed to identify possible prognostic factors for the survival end points.

RESULTS

76 patients were included in the analysis. Different RT dose and fractionation schedules were prescribed according to site, number, size of the lymph node(s) and to respect dose constraints for relevant organs at risk. Median biologically effective dose delivered was 75 Gy (interquartile range: 59-86 Gy). Treatment was optimal; one G1 acute toxicity and seven G1 late toxicities of any grade were recorded. Median follow-up time was 23.16 months. 16 patients (21.05%) had a local progression, while 52 patients progressed in distant sites (68.42 %).Median local relapse free survival was not reached, LC at 6, 12 and 24 months was 96.05% [confidence interval (CI) 88.26-98.71%], 86.68% (CI 75.86-92.87) and 68.21% (CI 51.89-80.00%), respectively. Median OS was 28.3 months (interquartile range 16.1-47.2). Median progression-freesurvival was 9.2 months (interquartile range 4.1-17.93).At multivariate analysis, RT dose, colorectal histology, systemic therapies were correlated with LC. Performance status and the presence of metastatic sites other than the thoracic nodes were correlated with OS. Local response was a predictor of OS.

CONCLUSION

IG-HRT for thoracic nodes was safe and feasible. Higher RT doses were correlated to better LC and should be taken in consideration at least in patients with isolated nodal metastases and colorectal histology.

ADVANCES IN KNOWLEDGE

Radiotherapy is safe and effective treatment for thoracic nodes metastases, higher radiotherapy doses are correlated to better LC. Oligometastatic patients can receive IG-HRT also for thoracic nodes metastases.

Prognostic Factors and Optimal Response Interval for Stereotactic Body Radiotherapy in Patients With Lung Oligometastases or Oligoprogression From Colorectal Cancer

Purpose: To analyze the prognostic factors and optimal response interval for stereotactic body radiotherapy (SBRT) in patients with lung oligometastases (OM) or oligoprogression (OP) from colorectal cancer (CRC).

Method: Patients with lung OM or OP from CRC treated by SBRT at our hospital were included in this retrospective review. The local control (LC), response to SBRT in different evaluation interval and regional metastases (RM) was analyzed. The risk factor for LC and RM was calculated using the Kaplan-Meier method and compared using the Log-rank test. Multivariate analysis with a Cox proportional hazards model was used to test independent significance.

Results: A total of 53 patients with 105 lung metastases lesions treated from 2012 to 2018 were involved in this retrospective study. The median biologically effective dose (BED) for these patients was 100 Gy (range: 75–131.2 Gy). Complete response (CR) increased from 27 (25.7%) to 46 (43.8%) lesions at 1.8 and 5.3 months following SBRT, and at the last follow-up, 52 (49.5%) lesions achieved CR. The median follow-up duration for all patients was 14 months (range: 5–63 months), and 1-year LC was 90.4%. During the follow-up, 10 lesions suffered local relapse after SBRT (9 of them occurred within 8 months after SBRT). The univariate analysis shows BED ≥ 100 Gy (P = 0.003) and gross tumor volume (GTV) < 1.6 cm³ (P = 0.011) were better predictors for 1-year LC. The patients with lung oligoprogression had higher 1-year RM when compared with patients with lung oligometastases (hazard ratio 2.78; 95% confidence interval [CI] 1.04–7.48, P = 0.042). Until the last follow up, 4 (7.5%) patients suffered grade 2 radiation pneumonitis, and no grade 3–4 toxicity was observed.

Conclusions: SBRT provides favorable LC in CRC patients with lung OM or OP, and the GTV and BED can affect the LC. Radiology examinations nearly 5–6 months following SBRT appear to represent the final local effect of SBRT, and the patients with oligoprogression has higher RM.

A meta-analysis of stereotactic radiotherapy for pulmonary oligometastases from colorectal cancer

BACKGROUND

For patients with colon cancer with lung metastasis, conventional radiotherapy is commonly used, which mainly acts on the double-stranded DNA inside the tumor cells. However, many foreign studies have found that increasing the dose of radiotherapy cannot improve the prognosis of patients, and because of its side effects on normal tissues, the commonly used dose of radiotherapy is usually between 60 and 70 Gy. However, the local control of lung tumors using this dose is not good. With the rapid development of science and technology, stereotactic body radiotherapy (SBRT) technology has been widely used in patients with non-small cell lung cancer, and SBRT is also used in patients with colon cancer and lung metastasis. However, some studies have found that because there are more hypoxic cells in colon cancer tissues than in other tissues, and hypoxic cells are relatively insensitive to radiation, the efficacy of SBRT in patients with lung metastasis from colon cancer is worse than that in patients with lung metastasis from other sites. However, this conclusion is controversial. There is no definite conclusion about the optimal dose of radiotherapy. Some studies have found that increasing the dose of radiotherapy can improve the prognosis of patients with colon cancer and lung metastasis. However, this conclusion is controversial. On the basis of many studies both in China and other countries, this study made a meta-analysis on the efficacy of SBRT in the treatment of colon cancer with lung metastasis and non-colon cancer with lung metastasis, as well as a comparison of the efficacy of different radiation doses in the treatment of colon cancer with lung metastasis, in order to provide evidence-based medicine-related evidence.

AIM

To compare the efficacy of stereotactic radiotherapy for colon cancer with lung metastasis and non-colon cancer with lung metastasis (Study 1), and to compare the efficacy of different doses of radiotherapy for colon cancer with lung metastasis (Study 2).

Methods

The controlled trials including cases with pulmonary oligometastases from colon cancer published from January 2008 to December 2018 were searched according to the method of the Cochrane Collaboration, and meta-analysis was carried out by using RevMan5.3 software.

Results

Fourteen studies were included, of which nine were included in Study 1, involving 486 patients with colon cancer and 938 with non-colon cancer, and five were included in Study 2, involving 157 patients treated with high doses and 185 treated with low doses. Meta-analysis indicated that the clinical efficacy of stereotactic radiotherapy for pulmonary oligometastases from colorectal was significantly lower than that for pulmonary oligometastases from other cancers, and that the efficacy of high doses was significantly better than that of low doses (P < 0.05).

Conclusion

SBRT has worse efficacy for pulmonary oligometastases from colorectal than for those from other cancer, and better efficacy for pulmonary oligometastases from colon cancer can be achieved by dose escalation.

Treatment outcomes of stereotactic ablative radiation therapy for non-spinal bone metastases: focus on response assessment and treatment indication

OBJECTIVE

To report treatment outcomes of stereotactic ablative radiation therapy (SABR) for non-spinal bone metastases in a single institution, and to compare assessments of Response Evaluation Criteria in Solid Tumors (RECIST) v. 1.1 and the University of Texas MD Anderson Cancer Center (MDA) criteria.

METHODS

From July 2011 to January 2017, 33 patients with 38 non-spinal bone metastatic lesions were treated using SABR. Treatment intent was categorized as follows: single metastasis or oligo-metastases; oligo-progression; and dominant areas of progression. Tumor responses were evaluated according to the RECIST and MDA criteria. Local control (LC) was defined as lesions that were not classified as progressive disease on both criteria.

RESULTS

The median follow-up period was 10.4 months (range, 2.5-47.4). Both 1- and 2 year LC rates were 94.2 %. The median overall survival (OS) was 20.2 months, and the median progression-free survival (PFS) was 6.9 months. Treatment intent was a significant factor for OS in multivariate analysis. The 1 year OS rates for single metastasis or oligo-metastasis, for oligo-progression, and for dominant areas of progression were 84.2%, 66.7%, and 0.0%, respectively ( p < 0.001). Overall response rate was 86.8 % according to MDA criteria, and 75.7 % according to RECIST criteria. When using MDA criteria, there appeared to be significant associations both between response and PFS (median 7.6 months for responders vs 2.5 months for non-responders; p = 0.036) and between response and OS. In contrast, when using RECIST criteria, the associations were significant neither between response and PFS (median 5.8 months for responders vs 9.3 months for non-responders; p = 0.522) nor between response and OS (25.7 months for responders vs 18.5 months for non-responders; p = 0.811).

CONCLUSION

SABR for non-spinal bone metastases demonstrated high LC rates with acceptable toxicity. The MDA criteria demonstrated advantages in predicting survival outcomes.

ADVANCES IN KNOWLEDGE

SABR for non-spinal bone metastases is a promising treatment option to achieve good local control. The MDA criteria, which is a newly proposed response evaluation criteria for bone metastases, has advantages in predicting survival outcomes compared to other established criteria.

Stereotactic Radiotherapy for Pulmonary Oligometastases From Colorectal Cancer: A Systematic Review and Meta-Analysis

PURPOSE

The purpose of this study was to determine whether pulmonary oligometastases from colorectal cancer have greater radioresistance than that of pulmonary oligometastases from other cancers and whether good local control can be achieved by dose escalation in stereotactic body radiotherapy.

MATERIALS AND METHODS

This systematic review and meta-analysis were conducted according to the preferred reporting items for systematic reviews and meta-analyses statement and methods. Studies were obtained from a database search of PubMed, Web of Science, and Google Scholar for publications using search terms designed to identify studies on "oligometastases," "lung," "stereotactic radiotherapy," and "colorectal cancer." For meta-analysis 1, studies that showed the number of local failures after stereotactic body radiotherapy for pulmonary metastases from colorectal carcinoma and other cancers were included. For meta-analysis2, studies in which a comparison was made of local control rates of pulmonary metastases from colorectal carcinoma by stereotactic body radiotherapy with a higher dose and that with a lower dose were included. A meta-analysis was performed using Mantel-Haenszel statics with the fixed or random-effect model by Review Manager 5.3.

RESULTS

Eighteen retrospective studies with 1920 patients with pulmonary oligometastases were used in meta-analysis 1. The local control rate in patients with pulmonary oligometastases from colorectal cancer was significantly lower than that in patients with pulmonary oligometastases from other cancers (odds ratio = 3.10, P < .00001). Next, 8 retrospective studies with 478 patients were included in meta-analysis 2 for dose escalation. Better local control was achieved by a higher prescription dose than by a lower prescription dose (odds ratio = 0.16, P < .00001).

CONCLUSION

Our meta-analysis indicated that local control of pulmonary oligometastases from colorectal cancer by stereotactic body radiotherapy was significantly worse than that of pulmonary metastases from other cancers; however, our results also indicated that good local control of pulmonary oligometastases from colorectal cancer can be achieved by dose escalation.

Predictive Factors for Response and Survival in a Cohort of Oligometastatic Patients Treated With Stereotactic Body Radiation Therapy

PURPOSE

This study evaluated patients, treatment, or disease characteristics that could predict response to stereotactic body radiation therapy (SBRT) and survival in a database of patients with oligometastatic disease from different solid tumors.

METHODS AND MATERIALS

Patients treated with SBRT for oligometastatic disease between 2014 and 2015 were included. Patients were defined as oligometastatic if they were affected by a maximum of 5 active lesions in 3 different sites. They had to be treated with SBRT with radical intent.

RESULTS

The study included 358 patients. With a median follow-up of 31.83 months, local control at 6 and 24 months was 94.6% and 78.9%, respectively. Distant progression was recorded in 279 patients (77.9%). Progression-free survival at 6 and 24 months was 66.1% and 18.4%, respectively. At last follow-up, 195 patients (54.5%) were still alive in 59 cases with no evidence of disease. The median overall survival (OS) was 34.7 months (95% confidence interval, 29.66-43.83). OS at 6 and 24 months was 96.07% and 63.57%, respectively. On multivariable analysis, the presence of lung metastases (hazard ratio [HR], 0.50 [0.33-0.75]; P = .001) and nodal metastases (HR, 0.44 [0.24-0.78]; P = .005) was related to longer OS. Primary lung cancer (HR, 1.89 [1.14-3.13]; P = .013), increasing age (HR, 1.02 [1.01-1.04]; P = .002), and the presence of metastatic sites other than the irradiated ones (HR, 2.19 [1.39-3.43]; P = .001) were all independent predictors of shorter OS. Local response was associated with OS.

CONCLUSIONS

SBRT for patients with oligometastatic disease is effective. Local response is strongly correlated with patients'' prognosis, also underlying its relevance in a metastatic setting.

A matched-pair analysis of stereotactic body radiotherapy (SBRT) for oligometastatic lung tumors from colorectal cancer versus early stage non-small cell lung cancer

BACKGROUND

The use of stereotactic body radiotherapy (SBRT) for early-stage primary non-small cell lung cancer (NSCLC) reported excellent local control rates. But the optimal SBRT dose for oligometastatic lung tumors (OLTs) from colorectal cancer (CRC) has not yet been determined. This study aimed to evaluate whether SBRT to a dose of 48-60 Gy in 4-5 fractions could result in similar local outcomes for OLTs from CRC as compared to early-stage NSCLC, and to examine potential dose-response relationships for OLTs from CRC.

METHODS

OLTs from CRC and primary NSCLCs treated with SBRT to 48-60 Gy in 4-5 fractions at a single institution were evaluated, and a matched-pair analysis was performed. Local recurrence-free survival (LRFS) was estimated by the Kaplan-Meier method. Univariate Cox regression was performed to identify significant predictors.

RESULTS

There were 72 lung lesions in 61 patients (24 OLTs from CRC in 15 patients and 48 NSCLCs in 46 patients) were analyzed with a median follow-up of 30 months. LRFS for OLTs from CRC was significantly worse than that of NSCLC when treated with 48-60 Gy/4-5 fx (p = 0.006). The 1, 3 and 5-year LRFS of OLTs from CRC vs NSCLC were 80.6% vs. 100%, 68.6% vs. 97.2%, and 68.6% vs. 81.0%, respectively. On univariate analysis, OLTs from CRC treated with higher dose (BED₁₀ = 132 Gy) exhibited significantly better local recurrence-free survival than those treated to lower doses (BED₁₀ ≤ 105.6 Gy) (p = 0.0022). The 1 and 3-year LRFS rates for OLTs treated to a higher dose (BED₁₀ = 132 Gy) were 88.9% and 81.5%, vs 33.3%, and not achieved for lower doses (BED₁₀ ≤ 105.6 Gy).

CONCLUSION

The LRFS of OLTs from CRC after SBRT of 48-60 Gy/4-5 fx was significantly worse than that of primary NSCLC. Lower dose SBRT appeared to have inferior control for OLTs of CRC in this cohort. Further studies with larger sample sizes are needed.

Quality of life changes after stereotactic ablative radiotherapy for liver metastases: A prospective cohort analysis

PURPOSE

To report the changes in quality of life (QoL) after stereotactic ablative radiotherapy (SABR) in patients with liver metastases (LM).

MATERIALS AND METHODS

A prospective cohort study was undertaken to measure the acute changes in QoL after SABR. Patients with 1-3 treated LM were eligible. Doses of 30-60 Gy in 3-5 fractions were delivered. Prospective QoL was measured using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaires, Core 15 for Palliative Care (EORTC QLQ-C15-PAL) and liver metastases (LM21), at baseline, 1st week and last day of treatment, then 1, 6 and 12 weeks after SABR. The functional living index-emesis (FLIE) was collected at baseline, 1st week, last day and 1 week after treatment. Univariable and multivariable linear mixed modeling were performed as appropriate to assess changes in QoL over time.

RESULTS

Sixty patients were included. The most common primary cancer was colorectal (42%). The global health score measured by QLQ-C15-PAL was significantly worse at treatment completion (p = 0.001), 1 week (p = 0.003) and 6 weeks (p = 0.002) after SABR but recovered by 12 weeks (p = 0.124). Nausea and constipation were worse at treatment completion (p < 0.05) but recovered 1 week after while fatigue recovered 6 weeks post-SABR. The majority of patients reported stable QoL at 12 weeks for all domains in the C15-PAL and LM21 questionnaires.

CONCLUSION

SABR offers a non-invasive mean of ablating LM with minimal impact on acute QoL.

The safety and effectiveness of stereotactic body radiotherapy for central versus ultracentral lung tumors

BACKGROUND AND PURPOSE

Recent studies have postulated that patients undergoing lung stereotactic body radiotherapy (SBRT) for ultracentral tumors have higher toxicity and mortality rates than those with central tumors. Our aim was to compare the outcomes after lung SBRT for central versus ultracentral tumors in our own series.

MATERIAL AND METHODS

This was a retrospective review of patients with primary and metastatic lung tumors treated with SBRT from 1 September 2009 to 30 June 2015. Patients were included if they were treated with five-fraction SBRT to central or ultracentral tumors. Central tumors were defined as tumors where the closest point was within 2 cm of (but not abutting) the proximal bronchial tree, or within 2 cm of (whether abutting or not) mediastinal structures. Ultracentral tumors were defined as tumors abutting the proximal bronchial tree. The 2-year overall survival (OS), 2-year local failure (LF), and 2-year grade ≥3 toxicity rates were compared between patients with central and ultracentral tumors.

RESULTS

A total of 107 patients were included in this study. There were no significant differences in 2-year OS between the two groups, with 2-year OS 57.7% for central tumors, and 50.4% for ultracentral tumors (p = 0.10). There were no significant differences in 2-year LF between the two groups, with 2-year LF 3.4% for central tumors and 4.3% for ultracentral tumors (p = 0.92). There were no significant differences in 2-year grade ≥3 toxicity rate for the two groups, with 3.5% with central tumors and 8.7% with ultracentral tumors (p = 0.23).

CONCLUSIONS

There were no significant differences in OS, LF, or grade ≥3 toxicity between patients with central and ultracentral lung tumors. Although these results indicate that SBRT for ultracentral tumors may be safe, caution should be applied in selecting and treating these patients until the completion of large prospective trials.

Stereotactic body radiotherapy for lung oligometastases: Literature review according to PICO criteria

Exhaustive criteria and definitive data to identify the ideal lung oligometastatic patient as a candidate for stereotactic body radiotherapy (SBRT) are lacking. Three distinct cohorts of oligometastatic patients could be distinguished: (1) patients with upfront diagnosis of oligometastases (synchronous or metachronous); (2) patients with oligorecurrent disease in terms of relapsed oligometastatic phase; (3) oligoprogressive patients after cytoreductive treatment. The aim of the present review is to analyze available data concerning the efficacy/safety of SBRT for oligometastatic/oligoprogressive/oligorecurrent lung metastases.

Approach to oligometastatic disease in head and neck cancer, on behalf of the GORTEC

Median survival for recurrent/metastatic head and neck squamous cell cancer (HNSCC) patients is about 10 months after first-line best systemic treatment. We aimed to assess current approaches of oligometastatic HNSCC patients by the analysis of current concept and published data (1995–2017) in this population. Five-year survival rates are over 20% in selected patients who undergo metastasis-directed therapy by either surgery or stereotactic irradiation. Human papillomavirus(+) HNSCC patients have more disseminated metastases but respond more favorably and also benefit from ablative treatments. Treatments of oligometastases are expanding rapidly. Unmet needs include revised imaging follow-up strategies to detect metastases earlier, identification of predictive noninvasive biomarkers for treatment guidance, assessment and corrections of biases in current studies and randomized clinical trials.

Acquired resistance to tyrosine kinase inhibitors may be linked with the decreased sensitivity to X-ray irradiation

Acquired resistance to chemotherapy and radiation therapy is one of the major obstacles decreasing efficiency of treatment of the oncologic diseases. In this study, on the two cell lines (ovarian carcinoma SKOV-3 and neuroblastoma NGP-127), we modeled acquired resistance to five target anticancer drugs. The cells were grown on gradually increasing concentrations of the clinically relevant tyrosine kinase inhibitors (TKIs) Sorafenib, Pazopanib and Sunitinib, and rapalogs Everolimus and Temsirolimus, for 20 weeks. After 20 weeks of culturing, the half-inhibitory concentrations (IC₅₀) increased by 25 – 186% for the particular combinations of the drugs and cell types. We next subjected cells to 10 Gy irradiation, a dose frequently used in clinical radiation therapy. For the SKOV-3, but not NGP-127 cells, for the TKIs Sorafenib, Pazopanib and Sunitinib, we noticed statistically significant increase in capacity to repair radiation-induced DNA double strand breaks compared to naïve control cells not previously treated with TKIs. These peculiarities were linked with the increased activation of ATM DNA repair pathway in the TKI-treated SKOV-3, but not NGP-127 cells. Our results provide a new cell culture model for studying anti-cancer therapy efficiency and evidence that there may be a tissue-specific radioresistance emerging as a side effect of treatment with TKIs.