Definitive results of a prospective non-randomized phase 2 study on stereotactic body radiation therapy (sbrt) for medically inoperable lung and liver oligometastases from breast cancer

BACKGROUND AND PURPOSE

To report mature results for local control and survival in oligometastatic (OM) breast cancer patients treated with stereotactic body radiotherapy (SBRT) on lung and/or liver lesions in a phase II trial.

METHODS

This is a prospective non-randomized phase II trial (NCT02581670) which enrolled patients from 2015 to 2021. Eligibility criteria included: age > 18 years, ECOG 0-2, diagnosis of breast cancer, maximum of 4 lung/liver lesions (with a maximum diameter < 5 cm), metastatic disease confined to the lungs and liver or extrapulmonary or extrahepatic disease stable or responding to systemic therapy. The primary end-points were local control (LC) and treatment-related toxicities. The secondary end-points included overall survival (OS), distant metastasis-free survival (DMFS), time to next systemic therapy (TTNS), poly-progression free survival (PPFS).

RESULTS

The study included 64 patients with a total of 90 lesions treated with SBRT. LC at 1 and 2 years was 94.9 %, 91 % at 3 years. Median local control was not reached. Median OS was 16.5 months, OS at 1, 2 and 3 years was 87.5 %, 60.9 % and 51.9 %, respectively. Median DMFS was 8.3 months, DMFS at 1, 2 and 3 years was 38.1 %, 20.6 % and 16 % respectively. At univariate analysis, local response to SBRT was found to be statistically linked with better OS, DMFS and STFS.

CONCLUSION

SBRT is a safe and valid option in oligometastatic breast cancer patients, with very high rates of local control. An optimal selection of patients is likely needed to improve survival outcomes and reduce the rate of distant progression.

Oligometastatic sarcoma treated with Curative intent Ablative Radiotherapy (OSCAR): A multicenter study on behalf of AIRO (Italian association of Radiotherapy and clinical Oncology)

BACKGROUND AND PURPOSE

Stereotactic Ablative Radiotherapy (SABR) is emerging as a valid alternative to surgery in the oligometastatic setting in soft tissue sarcomas (STS), although robust data are lacking. The aim of this study is to evaluate toxicity and efficacy of SABR in oligometastatic STS.

MATERIALS AND METHODS

This is a retrospective multicenter study including adult patients affected by stage IV STS, treated with SABR for a maximum of 5 cranial or extracranial metastases in up to 3 different organs. SABR was delivered with ablative purposes. Study endpoints were overall survival (OS), local control (LC), distant progression free survival (DPFS), time to polymetastatic progression (TTPP), time to new systemic therapy (TTNS) and toxicity.

RESULTS

From 10 Italian RT centers, 138 patients (202 metastases) treated between 2010 and 2022 were enrolled in the study. Treatment was generally well tolerated, no acute or late toxicity ≥ G3 was recorded. Median follow up was 42.5 months. Median OS was 39.7 months. Actuarial OS at 1 and 2 years was 91.5 % and 72.7 %. Actuarial LC at 1 and 2 years was 94.8 % and 88.0 %. Median DPFS was 9.7 months. Actuarial DPFS at 1 and 2 years was 40.8 % and 19.4 %.

CONCLUSION

SABR is a safe and effective approach for the treatment of oligometastatic sarcoma. One out of 5 patients is free of progression at 2-years.

Stereotactic Body Radiotherapy for Spine Oligometastases: A Multicentre Retrospective Study From the Italian Association of Radiotherapy and Clinical Oncology (AIRO)

AIM

To evaluate the efficacy of stereotactic body radiotherapy (SBRT) for spine oligometastases.

MATERIALS AND METHODS

This was a multicentre retrospective study of a series of patients who received SBRT for spine oligometastases. The efficacy of SBRT was evaluated in terms of local control as the primary endpoint. Survival outcomes were also analysed to identify predictive factors for clinical outcomes. Toxicity was assessed according to CTCAE v4.0.

RESULTS

Between March 2018 and July 2022, 183 lesions in 177 patients were analysed. In most patients, SBRT was delivered to a single spine metastasis (82%) for a median total dose of 21 Gy (14-35 Gy) in three fractions (one to five fractions) and a median BED10 = 119 Gy (57.7-152 Gy). Local control rates were 90.3% at 1 year, 84.3% at 2 years and 84.3% at 3 years. Distant progression-free survival rates were 33.1%, 18.5% and 12.4% at 1, 2 and 3 years, with prostate histology (P = 0.023), oligorecurrent disease (P = 0.04) and BED10 > 100 Gy (P = 0.04) found to be predictive on univariate analysis. A further oligometastatic progression was observed in 33 patients (18.6%) treated with a second course of SBRT, reporting at univariate analysis improved overall survival rates (P = 0.01). Polymetastases-free survival rates were 57.8%, 43.4% and 32.4%; concurrent therapy was related to improved outcomes at multivariate analysis (P = 0.009). Overall survival rates were 91.8%, 79.6% and 65.9%, with prostate histology and non-cervical metastases related to better overall survival at multivariate analysis. Pain-flare after SBRT was recorded in 3.3%; five patients underwent surgical decompression after SBRT; there were no grade ≥3 adverse events.

CONCLUSIONS

In our experience of only oligometastatic patients, spine SBRT gave excellent results in terms of safety and efficacy. Prostate histology and oligorecurrent disease were predictive factors for improved clinical outcomes; also, patients who experienced a further oligoprogression after SBRT maintained a survival advantage compared with polymetastatic progression. No severe adverse events were reported.

Oligometastatic Prostate Cancer Treated with Stereotactic Body Radiation Therapy: The Role of Three-Dimensional Tumour Volume in Patient Survival

AIMS

The definition of oligometastatic prostate cancer (OPCa) is currently based solely on the maximum number of detectable metastases, as there are no validated biomarkers available. The aim of this study was to identify novel predictive factors for OPCa patients who underwent metastases-directed therapy.

MATERIALS AND METHODS

This monocentre, retrospective study included consecutive OPCa patients with a maximum of five metastases in up to two organs, detected with choline- or PSMA-positron emission tomography, who were treated with metastases-directed stereotactic body radiation therapy. Endpoints were overall survival and progression-free survival, assessed with Kaplan-Meier analysis. Univariate and multivariable Cox regression was carried out to evaluate the association between clinical factors and survival outcomes.

RESULTS

Between 2009 and 2021, 163 patients and 320 metastases were treated with 226 stereotactic body radiation therapy courses. The median three-dimensional metastatic tumour volume was 4.1 cm3, with a range from 0.01 to 233.4 cm3. In total, 87 (53.4%), 21 (12.9%) and 55 (33.7%) metastases were classified as cN1, cM1a and cM1b, respectively. The median follow-up was 28.5 months. The rates of overall survival at 1, 3 and 5 years were 89.5% (95% confidence interval 83.4-93.4), 74.9% (95% confidence interval 66.1-81.7) and 57.2% (95% confidence interval 45.8-67.1), respectively. Multivariable analysis showed that overall survival reduced with the increase in three-dimensional total tumour volume (hazard ratio 1.93, 95% confidence interval 1.06-3.52; P = 0.030) and confirmed a significant difference between cN1 versus cM1a-b disease (hazard ratio 1.81, 95% confidence interval 1.01-3.25; P = 0.046). The cut-off value of total volume correlated with the highest risk of death was 20 cm3 (hazard ratio 2.37, 95% confidence interval 1.34-4.18; P = 0.003). The median progression-free survival was 17.8 months, with 1-, 3- and 5-year rates of 63.7% (95% confidence interval 55.4-70.9), 31.5% (95% confidence interval 22.8-40.6) and 24.7% (95% confidence interval 16.0-34.3).

CONCLUSIONS

This study identified three-dimensional total tumour volume and the site of oligometastases as significant predictors of survival in OPCa patients treated with metastases-directed therapy. These parameters can potentially be used to personalised treatment and improve patient outcome.

Three Months PSA Response after PSMA-Guided Approach for Biochemical Relapse after Prostatectomy (PSICHE Trial)

PURPOSE/OBJECTIVE(S)

Prostate bed salvage radiotherapy (SRT) is currently the main approach for early biochemical relapse (BR) after radical prostatectomy (RP). Nonetheless, 68Ga-PSMA-11 PET/CT implementation in this scenario prompted significant changes in patients' management. Our trial is aimed to prospectively assess the oncological outcomes after a pre-defined, 68Ga-PSMA-11 PET/CT based treatment strategy. In this analysis, we present early results focusing on three-months biochemical outcomes after treatment.

MATERIALS/METHODS

Inclusion criteria were BR after RP (PSA ≥0.2 ng/ml; < 1 ng/ml) +/- postoperative SRT. All patients with PSA persistence after RP (PSA >0.2 ng/ml within 16 weeks from surgery) were excluded from the trial. After centralized 68Ga-PSMA PET/CT, a pre-defined treatment approach was proposed, consisting in Observation and re-staging at further PSA progression in case of negative 68Ga-PSMA PET/CT and previous postoperative RT, prostate bed SRT in case of negative imaging or positive imaging within prostate bed, Stereotactic body radiotherapy (SBRT) to all sites of disease in patients with pelvic nodal recurrence or oligometastatic disease (defined as (< 3 non-visceral metastatic lesions) or Androgen deprivation therapy +/- other systemic treatment indicated for hormone sensitive prostate cancer for widespread metastatic disease. PSA ≤0.2 ng/ml or ≤ 50% of baseline were defined as Complete or partial biochemical response (CBR or PBR), respectively.

RESULTS

At present, 135 patients were enrolled within the protocol. Current analysis is focused on a cohort of patients with at least three months of follow up and excludes all patients who underwent only observation after re-staging due to previous prostate bed SRT (n = 42). In this subgroup, PBR or CBR were detected in 28 (66.7%) and 25 (59.5%) patients, respectively. PSA reduction if compared to baseline was detected in 34 patients, for an overall biochemical response rate of 80.9%. Biochemical progression after treatment was reported in 3 patients, who underwent a second 68Ga-PSMA PET/CT re-staging with detection of distant metastases.

CONCLUSION

Promising results after a 68Ga-PSMA PET/CT targeted salvage treatment strategy were reported in terms of early biochemical response. This approach may allow to defer systemic treatment in this setting. Biochemical relapse free and progression free survival will be the objects of further analysis after longer follow-up.

Long term results of a phase II trial of hypofractionated adjuvant radiotherapy for early-stage breast cancer with volumetric modulated arc therapy and simultaneous integrated boost

PURPOSE

to report toxicity and cosmetic outcome with a median follow-up of 6 years of a phase II trial of hypofractionated radiotherapy with volumetric modulated arc therapy (VMAT) and simultaneous integrated boost (SIB) for early-stage breast cancer after conservative surgery.

MATERIALS AND METHODS

From August 2010 to September 2014, patients requiring adjuvant radiotherapy for early-stage breast cancer were treated according to a phase I-II protocol with SIB to 40.5 and 48 Gy to the breast and the boost region, respectively, with VMAT technique. The primary endpoint evaluated the treatment feasibility regarding adherence to required dose constraints for target, heart and lungs. Acute and late toxicity, local and distant control were secondary endpoints.

RESULTS

450 patients were included in the trial and analysed after a median follow-up of 6 years. Acute toxicity was already presented in a previous paper. Regarding late toxicity, 93% of patients had no skin alteration at five years, while 5.3% and 1.3% did record G1 and G2 residual toxicity, respectively. Cosmetic outcome was scored good or excellent in almost all cases (97.2%), fair only in 2.3% of patients. Residual tenderness in the irradiated breast was reported by 10% of patients. Cosmesis and breast pain improved during follow-up. Two cases of G2 pneumonitis and two cases of ischemic cardiopathy were registered during follow-up. Five cases presented local recurrence in the homolateral breast, four patients had a new primary cancer in the contralateral breast, while distant metastasis developed in 7 patients.

CONCLUSION

After more than six years, hypofractionated VMAT with SIB for adjuvant radiotherapy in early-stage breast cancer patients remains a safe and effective approach. Mature data on skin toxicity and cosmetic outcome are encouraging. However, longer follow-up is required to evaluate local control, cardiac toxicity and secondary carcinogenesis.

Postoperative radiotherapy after upfront radical prostatectomy: debated issues at a turning point-a survey exploring management trends on behalf of AIRO (Italian Association of Radiotherapy and Clinical Oncology)

OBJECTIVES

Postoperative prostate cancer patients are a heterogeneous population, and many prognostic factors (e.g., local staging, PSA kinetics, margin status, histopathological features) may influence their clinical management. In this complex scenario, univocal recommendations are often lacking. For these reasons, the present survey was developed by the Italian Association of Radiotherapy and Clinical Oncology (AIRO) to collect the opinion of Italian radiation oncologists and delineate a representation of current clinical practice in our country.

METHODS

A questionnaire was administered online to AIRO (Italian Association of Radiotherapy and Clinical Oncology) members registered in 2020 with a clinical interest in uro-oncological disease.

RESULTS

Sixty-one per cent of AIRO members answered the proposed survey. Explored topics included career and expertise, indications to adjuvant RT, additional imaging in biochemical recurrence setting, use of salvage radiotherapy (SRT), management of clinically evident locoregional recurrence and future considerations.

CONCLUSIONS

Overall, good level of agreement was found between participants for most of the topics. Most debated issues regarded, as expected, implementation of new imaging methods in this setting. Notably, trend in favour of early SRT vs. immediate adjuvant RT was underlined, and preference for global evaluation rather than isolated risk factors for RT indications was noticed.

Elective neck irradiation in the management of esthesioneuroblastoma: a systematic review and meta-analysis

BACKGROUND

There is no consensus about the optimal management of the neck in clinically node negative esthesioneuroblastoma (ENB). The aim of this study is to assess the impact of elective neck irradiation (ENI) in terms of regional disease control and survival.

METHODS

The study was performed according to the PRISMA guidelines searching on Scopus, PubMed/MEDLINE, and Google Scholar databases. The primary outcome was the regional recurrence rate (RRR), that was reported as odds ratio (OR) and 95% confidence interval (CI). Secondary outcomes were the overall survival (OS), and the distant-metastases free survival (DMFS), that were reported as logarithm of the hazard ratios (logHRs) and 95% confidence intervals (CIs).

RESULTS

A total of 489 clinically node negative patients were included from 9 retrospective studies. ENI significantly reduced the risk of regional recurrence compared to no treatment. No difference was measured between ENI and observation, according to both OS and DMFS. No stratified analysis could be performed based on Kadish stage and Hyams grade.

CONCLUSIONS

ENI should be recommended to improve the regional disease control. No advantage was measured in terms of survival or distant metastases with a low quality of evidence. Further prospective studies should be designed to understand if ENI could be avoided in early stage and low-grade tumors.

Palliative radiotherapy in older adults with head and neck squamous cell carcinoma: A systematic review

Locally advanced Head and neck squamous cell carcinoma (SCCHN) represents a common oncologic pathology in older adults (OA). While radiotherapy represents a cornerstone in this context, it is unclear what is the optimal radiation regimen for SCCHN in the palliative setting, especially for OA. This article addresses issues related to palliative radiotherapy (PRT) in this setting with a focus on treatment modalities and toxicity. We also explore the use of quality of life and geriatric assessment in this setting. Medline, Scopus and Embase databases were queried for articles in this setting. We included studies published from January 1, 2000 through June 1, 2020, that were independently evaluated by two authors. Analyzed endpoints were progression free survival (PFS), overall survival (OS) and PRT toxicities. The meta-analysis was performed using Stata v.14. A total of 33 studies were included in this meta-analysis. The pooled median OS is 7.7 months, 2-years OS was worse for higher radiation dose (p = 0.02). The pooled median PFS was 5.4 months, PFS was influenced by EQD2 (p = 0.01), with patients receiving an EQD2 < 40 Gy that presented a poorer outcome. Regarding acute toxicities, most common pooled G3 toxicities were mucositis (7%) and dysphagia (15%). Among late toxicity, most common G3 toxicity was dysphagia in 7% of patients. Radiotherapy should be the most effective palliative treatment in symptomatic SCCHN OA. A tailored approach, guided by geriatric tools, would be indicated to choose the right therapy.

Stereotactic Body Radiation Therapy in the Management of Oligometastatic and Oligoprogressive Bladder Cancer and Other Urothelial Malignancies

AIMS

Bladder cancer represents the most common type of urothelial carcinoma, with a median overall survival of 12.5-15 months in the case of metastatic disease. We evaluated the role of stereotactic body radiation therapy (SBRT) in the management oligometastatic urothelial cancer.

MATERIALS AND METHODS

Data on patients with a maximum of five metastases were collected from three institutions. Concomitant systemic therapy was allowed. End points were the local control of treated metastases, distant progression-free survival (PFS), overall PFS and overall survival.

RESULTS

Data for 82 lesions and 61 patients were included. The primary tumour was located in the bladder in 82% of patients, followed by kidney pelvis (11.5%). The most common treated site was lung (40.2%). Twenty-nine (47.5%) and 14 (23%) patients received systemic therapy before and during SBRT, respectively. The median BED10 value was 78.7 Gy. The median follow-up was 17.2 months. Rates of local control at 1 and 2 years were 92% and 88.9%, respectively, with correlation with systemic therapy before SBRT (hazard ratio 2.62, P = 0.034). Overall PFS at 1 and 2 years was 47.9% and 38.1%, respectively. The number of metastases was a predictive factor (hazard ratio 2.65, P = 0.008). The median overall survival was 25.6 months. Total dose (hazard ratio 0.93, P = 0.003) and BED10 (hazard ratio 0.97, P = 0.006) were correlated with overall survival. No grade ≥2 adverse events were reported.

CONCLUSIONS

SBRT represents an effective and safe treatment in metastatic urothelial carcinoma. Prospective randomised trials are necessary to better evaluate the benefit on delaying the onset of new systemic therapies.

The use of radiation therapy for oligoprogressive/oligopersistent oncogene-driven non small cell lung cancer: State of the art

Oncogene-driven non small cell lung cancer (NSCLC) is a distinct entity in thoracic oncology. The availability of effective target therapies, like EGFR inhibitors or ALK inhibitors, have revolutionized the prognosis of these patients. However, despite an initial response in the majority of patients, drug resistance ultimately occurs. In some cases, this resistance develops in few clonal cells (oligoprogression), so that a local ablation of these resistant deposits could allow to maintain the same systemic therapy and possibly to prolong patients' survival. For these purposes, stereotactic body radiation therapy (SBRT) is an ideal local ablative treatment, because it is effective, non invasive and with limited side effects. In this review, we aim to analyze available clinical data to verify whether SBRT can allow these patients to continue with existing target therapy longer, delay the switch to other systemic therapies and improve their outcome modifying the natural history of the disease.

RapidPlan knowledge based planning: iterative learning process and model ability to steer planning strategies

Purpose

To determine if the performance of a knowledge based RapidPlan (RP) planning model could be improved with an iterative learning process, i.e. if plans generated by an RP model could be used as new input to re-train the model and achieve better performance.

Methods

Clinical VMAT plans from 83 patients presenting with head and neck cancer were selected to train an RP model, CL-1. With this model, new plans on the same patients were generated, and subsequently used as input to train a novel model, CL-2. Both models were validated on a cohort of 20 patients and dosimetric results compared. Another set of 83 plans was realised on the same patients with different planning criteria, by using a simple template with no attempt to manually improve the plan quality. Those plans were employed to train another model, TP-1. The differences between the plans generated by CL-1 and TP-1 for the validation cohort of patients were compared with respect to the differences between the original plans used to build the two models.

Results

The CL-2 model presented an improvement relative to CL-1, with higher R² values and better regression plots. The mean doses to parallel organs decreased with CL-2, while D_1% to serial organs increased (but not significantly). The different models CL-1 and TP-1 were able to yield plans according to each original strategy.

Conclusion

A refined RP model allowed the generation of plans with improved quality, mostly for parallel organs at risk and, possibly, also the intrinsic model quality.

The Potential Role of Intensity-modulated Proton Therapy in the Regional Nodal Irradiation of Breast Cancer: A Treatment Planning Study

AIMS

To investigate the role of intensity-modulated proton therapy (IMPT) for regional nodal irradiation in patients with breast carcinoma in comparison with volumetric-modulated arc therapy (VMAT).

MATERIALS AND METHODS

A cohort of 20 patients (10 in the breast-conserving surgery group and 10 post-mastectomy patients with tissue expander implants) was investigated. Proton plans were also computed using robust optimisation methods. Plan quality was assessed by means of dose-volume histograms and scored with conventional metrics. Estimates of the risk of secondary cancer induction (excess absolute risk, EAR) were carried out, taking into account fractionation, repopulation and repair.

RESULTS

Concerning target coverage, the data proved a substantial equivalence of VMAT and IMPT: for example, coverage for the 50 Gy target, expressed in terms of V_98%, was 47.8 ± 0.4, 47.6 ± 0.4, 47.3 ± 0.8, consistent with the objective of 47.5 Gy, for post-mastectomy patients for the three groups of patients. Also, the conformality of the dose distributions was similar for the two techniques, about 1.1, without statistically significant differences. Organ at risk planning aims were achieved for all structures for both techniques. The mean dose to the ipsilateral lung was 10.8 ± 1.1, 6.2 ± 0.8, 7.2 ± 1.0; for the contralateral lung was 3.2 ± 0.7, 0.3 ± 0.2, 0.4 ± 0.2; for the contralateral breast was: 3.1 ± 0.7, 0.3 ± 0.3 and 0.3 ± 0.3, whereas it was 3.9 ± 0.9, 0.4 ± 0.3 and 0.5 ± 0.5, respectively, for the heart for VMAT, IMPT and robust IMPT plans over the whole group of patients. Robust optimisation affected the near-to-maximum dose values for contralateral lung and breast, the mean dose for the heart and ipsilateral lung, with a deterioration ranging from 20 to 40% of the nominal value of IMPT plans (e.g. from 8.1 ± 6.4 to 11.4 ± 8.8 for the heart compared with 16.2 ± 5.2 for the VMAT plans). The numerical values of EAR per 10 000 patient-years were about one order of magnitude higher for VMAT than for IMPT for contralateral structures: 11.66 ± 2.01, 0.89 ± 0.80, 0.98 ± 0.77 for the contralateral breast and the three groups of plans, respectively; 14.31 ± 2.75, 1.42 ± 0.80, 1.78 ± 0.87 for the contralateral lung; and 34.86 ± 2.64, 18.85 ± 2.15, 20.98 ± 2.35 for the ipsilateral lung.

CONCLUSION

IMPT with or without robust optimisation seems to be a potentially promising approach for the radiation treatment of breast cancer when nodal volumes should be irradiated. This was measured in terms of dosimetric advantage and predicted clinical benefit. In fact, the significant reduction in estimated EAR could add further clinical value to the dosimetric sparing of the organs at risk achievable with IMPT.

What is the prognostic impact of FDG PET in locally advanced head and neck squamous cell carcinoma treated with concomitant chemo-radiotherapy? A systematic review and meta-analysis

PURPOSE

Evidence is conflicting on the prognostic value of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) in head and neck squamous cell carcinoma. The aim of our study was to determine the impact of semiquantitative and qualitative metabolic parameters on the outcome in patients managed with standard treatment for locally advanced disease.

METHODS

A systematic review of the literature was conducted. A meta-analysis was performed of studies providing estimates of relative risk (RR) for the association between semiquantitative metabolic parameters and efficacy outcome measures.

RESULTS

The analysis included 25 studies, for a total of 2,223 subjects. The most frequent primary tumour site was the oropharynx (1,150/2,223 patients, 51.7%). According to the available data, the majority of patients had stage III/IV disease (1,709/1,799, 94.9%; no information available in four studies) and were treated with standard concurrent chemoradiotherapy (1,562/2,009 patients, 77.7%; only one study without available information). A total of 11, 8 and 4 independent studies provided RR estimates for the association between baseline FDG PET metrics and overall survival (OS), progression-free survival (PFS) and locoregional control (LRC), respectively. High pretreatment metabolic tumour volume (MTV) was significantly associated with a worse OS (summary RR 1.86, 95% CI 1.08-3.21), PFS (summary RR 1.81, 95% CI 1.14-2.89) and LRC (summary RR 3.49, 95% CI 1.65-7.35). Given the large heterogeneity (I2 > 50%) affecting the summary measures, no cumulative threshold for an unfavourable prognosis could be defined. No statistically significant association was found between SUVmax and any of the outcome measures.

CONCLUSION

FDG PET has prognostic relevance in the context of locally advanced head and neck squamous cell carcinoma. Pretreatment MTV is the only metabolic variable with a significant impact on patient outcome. Because of the heterogeneity and the lack of standardized methodology, no definitive conclusions on optimal cut-off values can be drawn.