Integrating stereotactic radiotherapy and systemic therapies

This paper focuses on stereotactic radiotherapy (SRT ) interactions with targeted therapies and immune system modulating agents because SRT inevitably interacts with them in the treatment of oligometastatic patients.

Radiation oncologists need to be aware of the advantages and risks of these interactions which can, on one hand, enhance the effect of therapy or, on the other, potentiate reciprocal toxicities. To date, few prospective studies have evaluated the interactions of SRT with new-generation drugs and data are mainly based on retrospective experiences, which are often related to small sample sizes.

Definition of the Prognostic Role of MGMT Promoter Methylation Value by Pyrosequencing in Newly Diagnosed IDH Wild-Type Glioblastoma Patients Treated with Radiochemotherapy: A Large Multicenter Study

Background. O6-methylguanine (O6-MeG)-DNA methyltransferase (MGMT) methylation status is a predictive factor for alkylating treatment efficacy in glioblastoma patients, but its prognostic role is still unclear. We performed a large, multicenter study to evaluate the association between MGMT methylation value and survival. Methods. We evaluated glioblastoma patients with an assessment of MGMT methylation status by pyrosequencing from nine Italian centers. The inclusion criteria were histological diagnosis of IDH wild-type glioblastoma, Eastern Cooperative Oncology Group Performance Status (ECOG-PS) ≤2, and radio-chemotherapy treatment with temozolomide. The relationship between OS and MGMT was investigated with a time-dependent Receiver Operating Characteristics (ROC) curve and Cox regression models. Results. In total, 591 newly diagnosed glioblastoma patients were analyzed. The median OS was 16.2 months. The ROC analysis suggested a cut-off of 15% for MGMT methylation. The 2-year Overall Survival (OS) was 18.3% and 51.8% for MGMT methylation <15% and ≥15% (p < 0.0001). In the multivariable analysis, MGMT methylation <15% was associated with impaired survival (p < 0.00001). However, we also found a non-linear association between MGMT methylation and OS (p = 0.002): median OS was 14.8 months for MGMT in 0−4%, 18.9 months for MGMT in 4−40%, and 29.9 months for MGMT in 40−100%. Conclusions. Our findings suggested a non-linear relationship between OS and MGMT promoter methylation, which implies a varying magnitude of prognostic effect across values of MGMT promoter methylation by pyrosequencing in newly diagnosed IDH wild-type glioblastoma patients treated with chemoradiotherapy.

Stereotactic radiotherapy for oligometastases in the lymph nodes

Even though systemic therapy is standard treatment for lymph node metastases, metastasis-directed stereotactic radiotherapy (SRT ) seems to be a valid option in oligometastatic patients with a low disease burden.

Positron emission tomography-computed tomography (PET-CT ) is the gold standard for assessing metastases to the lymph nodes; co-registration of PET-CT images and planning CT images are the basis for gross tumor volume (GTV ) delineation. Appropriate techniques are needed to overcome target motion. SRT schedules depend on the irradiation site, target volume and dose constraints to the organs at risk (OARs) of toxicity. Although several fractionation schemes were reported, total doses of 48–60 Gy in 4–8 fractions were proposed for mediastinal lymph node SRT, with the spinal cord, esophagus, heart and proximal bronchial tree being the dose limiting OAR s. Total doses ranged from 30 to 45 Gy, with daily fractions of 7–12 Gy for abdominal lymph nodes, with dose limiting OARs being the liver, kidneys, bowel and bladder. SRT on lymph node metastases is safe; late side effects, particularly severe, are rare.

Stereotactic radiotherapy for bone oligometastases

About 60–90% of cancer patients are estimated to develop bone metastases, particularly in the spine.

Bone scintigraphy, computed tomography (CT ) and magnetic resonance imaging (MRI ) are currently used to assess metastatic bone disease; positron emission tomography/computed tomography (PET-CT ) has become more widespread in clinical practice because of its high sensitivity and specificity with about 95% diagnostic accuracy. The most common and well-known radiotracer is 18F-fluorodeoxyglucose (¹⁸FDG); several other PET-radiotracers are currently under investigation for different solid tumors, such as ¹¹C or ¹⁸FDG-choline and prostate specific membrane antigen (PSMA)-PET/CT for prostate cancer. In treatment planning, standard and investigational imaging modalities should be registered with the planning CT so as to best define the bone target volume. For target volume delineation of spine metastases, the International Spine Radiosurgery Consortium (ISRC ) of North American experts provided consensus guidelines. Single fraction stereotactic radiotherapy (SRT ) doses ranged from 12 to 24 Gy; fractionated SRT administered 21–27 Gy in 3 fractions or 20–35 Gy in 5 fractions. After spine SRT, less than 5% of patients experienced grade ≥ 3 acute toxicity. Late toxicity included the extremely rare radiation-induced myelopathy and a 14% risk of de novo vertebral compression fractures.

Impact of recurrence pattern in patients undergoing a second surgery for recurrent glioblastoma

The impact of different patterns of glioblastoma (GBM) recurrence has not yet been fully established in patients suitable for a second surgery. Through the present observational study carried out at Pisa University Hospital, we aimed to investigate how different patterns of GBM failure influence second surgery outcomes. Overall survival (OS) and post-recurrence survival (PRS) were assessed according to clinical characteristics, including pattern of recurrence, in a prospective cohort of recurrent GBM patients. Survival curves were calculated using the Kaplan-Meier method and the log-rank test was applied to evaluate the differences between curves. Patients with local recurrence had better OS than patients with non-local one, 24.1 versus 18.2 months, respectively [P = 0.015, HR = 1.856 (1.130-3.050)]. The second surgery conferred an advantage in OS respect to non-operated patients, however, this advantage was more evident in patients with local recurrence [P = 0.002 with HR 0.212 (95% CI 0.081-0.552) and P = 0.029 with HR = 0.522 (95% CI 0.291-0.936), respectively]. The recurrence pattern can influence the outcome of patients with recurrent GBM suitable for a second surgery.

[18F]FMCH PET/CT biomarkers and similarity analysis to refine the definition of oligometastatic prostate cancer

Background

The role of image-derived biomarkers in recurrent oligometastatic Prostate Cancer (PCa) is unexplored. This paper aimed to evaluate [¹⁸F]FMCH PET/CT radiomic analysis in patients with recurrent PCa after primary radical therapy. Specifically, we tested intra-patient lesions similarity in oligometastatic and plurimetastatic PCa, comparing the two most used definitions of oligometastatic disease.

Methods

PCa patients eligible for [¹⁸F]FMCH PET/CT presenting biochemical failure after first-line curative treatments were invited to participate in this prospective observational trial. PET/CT images of 92 patients were visually and quantitatively analyzed. Each patient was classified as oligometastatic or plurimetastatic according to the total number of detected lesions (up to 3 and up to 5 or > 3 and > 5, respectively). Univariate and intra-patient lesions' similarity analysis were performed.

Results

[¹⁸F]FMCH PET/CT identified 370 lesions, anatomically classified as regional lymph nodes and distant metastases. Thirty-eight and 54 patients were designed oligometastatic and plurimetastatic, respectively, using a 3-lesion threshold. The number of oligometastic scaled up to 60 patients (thus 32 plurimetastatic patients) with a 5-lesion threshold. Similarity analysis showed high lesions' heterogeneity. Grouping patients according to the number of metastases, patients with oligometastatic PCa defined with a 5-lesion threshold presented lesions heterogeneity comparable to plurimetastic patients. Lesions within patients having a limited tumor burden as defined by three lesions were characterized by less heterogeneity.

Conclusions

We found a comparable heterogeneity between patients with up to five lesions and plurimetastic patients, while patients with up to three lesions were less heterogeneous than plurimetastatic patients, featuring different cells phenotypes in the two groups. Our results supported the use of a 3-lesion threshold to define oligometastatic PCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13550-021-00858-8.

A multicenter LArge retrospectIve daTabase on the personalization of Stereotactic ABlative Radiotherapy use in lung metastases from colon-rectal cancer: the LaIT-SABR study

INTRODUCTION

stereotactic ablative radiotherapy (SABR) has been shown to increase survival in oligometastatic disease, but local control of colorectal metastases remains poor. We aimed to identify potential predictive factors of SBRT response through a multicenter large retrospective database and to investigate the progression to the polymetastatic disease (PMD).

MATERIAL AND METHODS

the study involved 23 centers, and was approved by the Ethical Committee (Prot. Negrar 2019-ZT). 1033 lung metastases were reported. Clinical and biological parameters were evaluated as predictive for local progression-free survival (FLP). Secondary end-point was the time to the polymetastatic conversion (tPMC).

RESULTS

Two-year FLP was 75.4%. Two-year FLP for lesions treated with a BED <100 Gy, 100-124 Gy, and ≥125 Gy was 76.1%, 70.6%, and 94% (p=0.000). Two-year FLP for lesion measuring ≤10 mm, 10-20 mm, and >20 mm was 79.7%, 77.1%, and 66.6% (p=0.027). At the multivariate analysis a BED ≥125 Gy significantly reduced the risk of local progression (HR 0.24, 95%CI 0.11-0.51; p=0.000). Median tPMC was 26.8 months. Lesions treated with BED ≥125 Gy reported a significantly longer tPMC as compared to lower BED. The median tPMC for patients treated to 1, 2-3 or 4-5 simultaneous oligometastases was 28.5, 25.4, and 9.8 months (p=0.035).

CONCLUSION

The present is the largest series of lung colorectal metastases treated with SABR. The results support the use of SBRT in lung oligometastatic colorectal cancer patients as it might delay the transition to PMD or offer relatively long disease-free period in selected cases. Predictive factors were identified for treatment personalization.

Adjuvant Radiotherapy in Patients With Pancreatic Adenocarcinoma. Is It Still Appealing in Clinical Trials? A Meta-analysis and Review of the Literature

AIM

Pancreatic adenocarcinoma is a life-threatening disease with a rising frequency and the fourth leading cause of cancer death. This review aimed to assess the impact of postoperative radiotherapy through a meta-analysis of prospective randomized studies.

MATERIALS AND METHODS

Six studies met the inclusion criteria and were analyzed to calculate the cumulative risk of death (hazard ratio) in patients affected by pancreatic cancer treated with or without radiotherapy. Higgins' index was used to determine heterogeneity in between-study variability and, subsequently, the random-effects model was applied according to DerSimonian and Laird.

RESULTS

Eight hundred and thirty-seven patients were analyzed (418 in the control arm and 419 in the treatment one), the hazard ratio for death after randomization was 0.92 (p=0.560, 95% confidence interval=0.70-1.22). When scrutinizing these studies, only one out of six showed a statistically significant benefit due to the addition of radiotherapy in the postoperative setting.

CONCLUSION

We conclude that the use of adjuvant radiotherapy is not beneficial in treating all patients affected by pancreatic cancer but only for a subset of cases with potential residual local disease.

Surgical outcome and molecular pattern characterization of recurrent glioblastoma multiforme: A single-center retrospective series

OBJECTIVE

Despite recent advances in diagnosis and treatment of the disease, the prognosis of patients with glioblastoma multiforme (GBM) remains poor. While the value of molecular pattern profiles at first diagnosis has been demonstrated, only few studies have examined these biomarkers at the time of recurrence. The aim of this study was to explore the impact of extent of resection at repeated craniotomy on overall survival (OS) of patients with recurrent GBM. In addition, we investigated the molecular pattern profiles at first and second surgery to evaluate possible temporal evolution of these patterns and to assess the effect of these modifications on OS.

METHODS

We conducted a retrospective cohort study of 63 patients (mean age 59.2 years) surgically treated at least two times for recurrent GBM between 2006 and 2020.

RESULTS

Median OS and progression-free survival (PFS) were 22 months (range 2-168 months) and 10 months (range 1-96 months), respectively. The OS following gross-total resection (GTR) at recurrence for patients with initial GTR (GTR/GTR) was significantly increased (42.6 months) compared with sub-total resection (STR) at reoperation after initial GTR (GTR/STR) (19 months) and with GTR at reoperation after initial STR (STR/GTR) (17 months) (p = 0.0004). Overall surgical morbidity resulted 12.7% and 11.1% at first and at second surgery, respectively. Changes in genetic profiles between first and second surgery of 1p/19q co-deletion, MGMT promoter methylation and p53 mutations occurred in 5.6%, 1.9% and 9.3% of cases, respectively. MGMT promoter methylation appeared to affect OS in univariate analysis at first (p = 0.038) and second surgery (p = 0.107), whereas p53 mutation appeared to affect OS only at second surgery (p = 0.01). In a multivariate analysis female sex (HR = 0.322, 95% CI 0.147-0.705; p = 0.005), PFS (HR = 0.959, 95% CI 0.934-0.986; p = 0.003), GTR at first and second surgery (HR = 0.195, 95% CI 0.091-0.419; p < 0.0001) and adjuvant chemotherapy at recurrence (HR = 0.407, 95% CI 0.206-0.809; p = 0.01) were associated with longer OS.

CONCLUSIONS

This study confirmed the role of extent of resection (EOR) at first and at recurrence as a significant predictor of outcome in patients with recurrent GBM. In addition, this study highlighted the concept of a dynamic evolution of GBM genome after initial surgical resection, supporting the need of further studies to investigate the clinical and therapeutic implications of the changes in genetic profiles after initial surgery.

Sustained Tumor Control With MAPK Inhibition in BRAF V600-Mutant Adult Glial and Glioneuronal Tumors

OBJECTIVE

To assess whether RAF and MEK inhibitors (RAFi/MEKi) can provide long-term clinical benefit in adult patients with BRAF V600-mutant glial and glioneuronal tumors (GGNTs), we analyzed tumor response and long-term outcome in a retrospective cohort.

METHODS

We performed a retrospective search in the institutional databases of 6 neuro-oncology departments for adult patients with recurrent or disseminated BRAF V600-mutant GGNTs treated with RAFi/MEKi.

RESULTS

Twenty-eight adults with recurrent or disseminated BRAF V600-mutant gangliogliomas (n = 9), pleomorphic xanthoastrocytomas (n = 9), and diffuse gliomas (n = 10) were included in the study. At the time that treatment with RAFi/MEKi was started, all tumors displayed radiologic features of high-grade neoplasms. Thirteen patients received RAFi as single agents (vemurafenib [n = 11], dabrafenib [n = 2]), and 15 received combinations of RAFi/MEKi (vemurafenib + cobimetinib [n = 5], dabrafenib + trametinib [n = 10]). Eleven patients achieved a partial or complete response (11 of 28, 39%), with a median reduction of -78% in their tumor burden. Responders experienced a median increase of 10 points in their Karnofsky Performance Status (KPS) score and a median progression-free survival of 18 months, which was longer than achieved with first-line treatment (i.e., 7 months, p = 0.047). Responders had better KPS score (p = 0.018) and tended to be younger (p = 0.061) and to be treated earlier (p = 0.099) compared to nonresponders. Five patients were rechallenged with RAFi/MEKi at progression, with novel tumor responses in 2. On univariate and multivariate analyses, response to RAFi/MEKi was an independent predictor of overall survival.

CONCLUSIONS

Our study highlights the long-term clinical benefits of RAFi/MEKi in adult patients with BRAF V600-mutant GGNTs and encourages rechallenge in responders.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that, for adult patients with BRAF V600-mutant GGNT, RAFi/MEKi can reduce tumor burden and provide clinical benefit.

Immunotherapy in association with stereotactic radiotherapy for Non-Small Cell Lung Cancer brain metastases: results from a multicentric retrospective study on behalf of AIRO

BACKGROUND

To define efficacy and toxicity of Immunotherapy (IT) with stereotactic radiotherapy (SRT) including radiosurgery (RS) or hypofractionated SRT (HFSRT) for brain metastases (BM) from Non-Small Cell Lung Cancer (NSCLC) in a multicentric retrospective study from AIRO (Italian Association of Radiotherapy and Clinical Oncology).

METHODS

NSCLC patients with BM receiving SRT+IT and treated in 19 Italian centers were analysed and compared with a control group of patients treated with exclusive SRT.

RESULTS

One hundred patients treated with SRT+IT and 50 patients treated with SRT-alone were included. Patients receiving SRT+IT had a longer intracranial Local Progression Free Survival (iLPFS) (propensity score-adjusted p=0.007). Among patients who, at the diagnosis of BM, received IT and had also extracranial progression (n=24), IT administration after SRT was shown to be related to a better overall survival (OS) (p=0.037). At multivariate analysis, non-adenocarcinoma histology, KPS =70 and use of HFSRT were associated with a significantly worse survival (p=0.019, p=0.017 and p=0.007 respectively). Time interval between SRT and IT ≤7 days (n=90) was shown to be related to a longer OS if compared to SRT-IT interval >7 days (n=10) (propensity score-adjusted p=0.008). The combined treatment was well tolerated. No significant difference in terms of radionecrosis between SRT+IT patients and SRT-alone patients was observed. Time interval between SRT and IT had no impact on toxicity rate.

CONCLUSIONS

Combined SRT+IT was a safe approach, associated with a better iLPFS if compared to exclusive SRT.

Association of XRCC3 rs1799794 polymorphism with survival of glioblastoma multiforme patients treated with combined radio-chemotherapy

This study reports the results of a monocentric prospective analysis conducted with the aim of evaluating the impact of XRCC1 rs25487, XRCC3 rs861539, XRCC3 rs1799794, RAD51 rs1801320 and GSTP-1 rs1695 single nucleotide polymorphisms (SNP) on patients with high-grade glioma treated with concomitant radio-chemotherapy. From October 2010 to August 2019, a total of 75 patients aged ≥18 years, with histological diagnosis of high-grade glioma, isocitrate dehydrogenase (IDH) 1/2 wild type and treated with radio-chemotherapy and sequential chemotherapy with temozolomide (TMZ) were prospectively recruited. The local ethic committee approved this study (Comitato Etico di Area Vasta Nord Ovest [CEAVNO]; protocol 3304/2011). After a median follow up of 25 months (range: 7-98 months), median progression-free survival (PFS) and overall survival (OS) were 11 months (CI95%: 8-14 months) and 18 months (CI95%: 15-21 months), respectively. In univariate and multivariate Cox regression analysis, a statistically significant association with PFS and OS was found with XRCC3 rs1799794 SNP. The study suggests that XRCC3 rs1799794 SNP can be associated with different PFS and OS in glioblastoma patients treated with radio-chemotherapy.

Brain metastases from primary colorectal cancer: is radiosurgery an effective treatment approach? Results of a multicenter study of the radiation and clinical oncology Italian association (AIRO)

OBJECTIVES

The prognosis of brain metastatic colorectal cancer patients (BMCRC) is poor. Several local treatments have been used, but the optimal treatment choice remains an unresolved issue. We evaluated the clinical outcomes of a large series of BMCRC patients treated in several Italian centers using stereotactic radiosurgery (SRS).

METHODS

185 BMCRC patients for a total of 262 lesions treated were evaluated. Treatments included surgery followed by post-operative SRS to the resection cavity, and SRS, either single-fraction, then hypofractionated SRS (HSRS). Outcomes was measured in terms of local control (LC), toxicities, brain distant failure (BDF), and overall survival (OS). Prognostic factors influencing survival were assed too.

RESULTS

The median follow-up time was 33 months (range 3-183 months). Surgery plus SRS have been performed in 28 (10.7%) cases, SRS in 141 (53.8%), and HSRS in 93 (35.5%). 77 (41.6%) patients received systemic therapy. The main total dose and fractionation used were 24 Gy in single fraction or 24 Gy in three daily fractions. Local recurrence occurred in 32 (17.3%) patients. Median, 6 months,1-year-LC were 86 months (95%CI 36-86), 87.2% ± 2.8, 77.8% ± 4.1. Median,6 months,1-year-BDF were 23 months (95%CI 9-44), 66.4% ± 3.9, 55.3% ± 4.5. Median,6 months,1-year-OS were 7 months (95% CI 6-9), 52.7% ± 3.6, 33% ± 3.5. No severe neurological toxicity occurred. Stage at diagnosis, Karnofsky Performance Status (KPS), presence and number of extracranial metastases, and disease-specific-graded-prognostic-assessment (DS-GPA) score were observed as conditioning survival.

CONCLUSION

SRS/HSRS have proven to be an effective local treatment for BMCRC. A careful evaluation of prognostic factors as well as a multidisciplinary evaluation is a valid aid to manage the optimal therapeutic strategy for CTC patients with BMs.

ADVANCES IN KNOWLEDGE

The prognosis of BMCRC is poor. Several local treatments was used, but optimal treatment choice remains undefined. Radiosurgery has proven to be an effective local treatment for BMCRC. A careful evaluation of prognostic factors and a multidisciplinary evaluation needed.

Clinical Management of Diffuse Low-Grade Gliomas

Diffuse low-grade gliomas (LGG) represent a heterogeneous group of primary brain tumors arising from supporting glial cells and usually affecting young adults. Advances in the knowledge of molecular profile of these tumors, including mutations in the isocitrate dehydrogenase genes, or 1p/19q codeletion, and in neuroradiological techniques have contributed to the diagnosis, prognostic stratification, and follow-up of these tumors. Optimal post-operative management of LGG is still controversial, though radiation therapy and chemotherapy remain the optimal treatments after surgical resection in selected patients. In this review, we report the most important and recent research on clinical and molecular features, new neuroradiological techniques, the different therapeutic modalities, and new opportunities for personalized targeted therapy and supportive care.