Clinical outcomes after online adaptive MR-guided stereotactic body radiotherapy for pancreatic tumors on a 1.5 T MR-linac

Introduction

Online adaptive magnetic resonance-guided radiotherapy (MRgRT) is a promising treatment modality for pancreatic cancer and is being employed by an increasing number of centers worldwide. However, clinical outcomes have only been reported on a small scale, often from single institutes and in the context of clinical trials, in which strict patient selection might limit generalizability of outcomes. This study presents clinical outcomes of a large, international cohort of patients with (peri)pancreatic tumors treated with online adaptive MRgRT.

Methods

We evaluated clinical outcomes and treatment details of patients with (peri)pancreatic tumors treated on a 1.5 Tesla (T) MR-linac in two large-volume treatment centers participating in the prospective MOMENTUM cohort (NCT04075305). Treatments were evaluated through schematics, dosage, delivery strategies, and success rates. Acute toxicity was assessed until 3 months after MRgRT started, and late toxicity from 3-12 months of follow-up (FU). The EORTC QLQ-C30 questionnaire was used to evaluate the quality of life (QoL) at baseline and 3 months of FU. Furthermore, we used the Kaplan-Meier analysis to calculate the cumulative overall survival.

Results

A total of 80 patients were assessed with a median FU of 8 months (range 1-39 months). There were 34 patients who had an unresectable primary tumor or were medically inoperable, 29 who had an isolated local recurrence, and 17 who had an oligometastasis. A total of 357 of the 358 fractions from all hypofractionated schemes were delivered as planned. Grade 3-4 acute toxicity occurred in 3 of 59 patients (5%) with hypofractionated MRgRT and grade 3-4 late toxicity in 5 of 41 patients (12%). Six patients died within 3 months after MRgRT; in one of these patients, RT attribution could not be ruled out as cause of death. The QLQ-C30 global health status remained stable from baseline to 3 months FU (70.5 at baseline, median change of +2.7 [P = 0.5]). The 1-year cumulative overall survival for the entire cohort was 67%, and that for the primary tumor group was 66%.

Conclusion

Online adaptive MRgRT for (peri)pancreatic tumors on a 1.5 T MR-Linac could be delivered as planned, with low numbers of missed fractions. In addition, treatments were associated with limited grade 3-4 toxicity and a stable QoL at 3 months of FU.

Feasibility of online radial magnetic resonance imaging for adaptive radiotherapy of pancreatic tumors

Background and purpose

Online adaptive magnetic resonance (MR)-guided treatment planning for pancreatic tumors on 1.5T systems typically employs Cartesian 3D T ₂w magnetic resonance imaging (MRI). The main disadvantage of this sequence is that respiratory motion results in substantial blurring in the abdomen, which can hamper delineation accuracy. This study investigated the use of two motion-robust radial MRI sequences as main delineation scan for pancreatic MR-guided radiotherapy.

Materials and methods

Twelve patients with pancreatic tumors were imaged with a 3D T ₂w scan, a Periodically Rotated Overlapping ParallEL Lines with Enhanced Reconstruction (PROPELLER) scan (partially overlapping strips), and a 3D Vane scan (stack-of-stars), on a 1.5T MR-Linac under abdominal compression. The scans were assessed by three radiation oncologists for their suitability for online adaptive delineation. A quantitative comparison was made for gradient entropy and the effect of motion on apparent target position.

Results

The PROPELLER scans were selected as first preference in 56% of the cases, the 3D T ₂w in 42% and the 3D Vane in 3%. PROPELLER scans sometimes contained a large interslice variation which would have compromised delineation. Gradient entropy was significantly higher in 3D T ₂w patient scans. The apparent target position was more sensitive to motion amplitude in the PROPELLER scans, but substantial offsets did not occur under 10 mm peak-to-peak.

Conclusion

PROPELLER MRI may be a superior imaging sequence for pancreatic MRgRT compared to standard Cartesian sequences. The large interslice variation should be mitigated through further sequence optimization before PROPELLER can be adopted for online treatment adaptation.

Patient-Reported Outcomes of Oligometastatic Patients After Conventional or Stereotactic Radiation Therapy to Bone Metastases: An Analysis of the PRESENT Cohort

PURPOSE

Stereotactic body radiation therapy (SBRT) has become a widely adopted treatment for patients with oligometastatic disease, despite limited evidence of superiority. We compared pain response and quality of life (QoL) in patients with oligometastatic disease treated with conventionally fractionated 3-dimensional radiation therapy (3DCRT) or SBRT to bone metastases.

METHODS AND MATERIALS

We included patients with oligometastatic disease (≤5 lesions within ≤3 organs) treated within the prospective PRESENT cohort. Main outcomes were pain response, clinical local control, and QoL 2, 4, and 8 weeks and 3, 6, and 12 months after treatment. Pain response was assessed only in patients who reported pain at baseline and was defined according to international consensus criteria.

RESULTS

Of 131 patients with oligometastatic disease, 66 patients were treated with 3DCRT and 65 patients with SBRT. A pain response was achieved in 81% (3DCRT) versus 84% (SBRT) with a median duration of 23 weeks (range, 1-58) and 24 weeks (range, 0-50), respectively. Reirradiation was needed in 33% versus 5% of the patients, respectively. None of the QoL subscales were significantly different between both groups.

CONCLUSIONS

In patients with oligometastatic disease, SBRT to bone metastases did not improve pain response or QoL compared with 3DCRT. Reirradiation was less often needed in the SBRT group.

Addition of zoledronic acid to neoadjuvant chemotherapy is not beneficial in patients with HER2-negative stage II/III breast cancer: 5-year survival analysis of the NEOZOTAC trial (BOOG 2010-01)

BACKGROUND

Adjuvant bisphosphonates are associated with improved breast cancer survival in postmenopausal patients. Addition of zoledronic acid (ZA) to neoadjuvant chemotherapy did not improve pathological complete response in the phase III NEOZOTAC trial. Here we report the results of the secondary endpoints, disease-free survival, (DFS) and overall survival (OS).

PATIENTS AND METHODS

Patients with HER2-negative, stage II/III breast cancer were randomized to receive the standard 6 cycles of neoadjuvant TAC (docetaxel/doxorubicin/cyclophosphamide) chemotherapy with or without 4 mg intravenous (IV) ZA administered within 24 h of chemotherapy. This was repeated every 21 days for 6 cycles. Cox regression models were used to evaluate the effect of ZA and covariates on DFS and OS. Regression models were used to examine the association between insulin, glucose, insulin growth factor-1 (IGF-1) levels, and IGF-1 receptor (IGF-1R) expression with survival outcomes.

RESULTS

Two hundred forty-six women were eligible for inclusion. After a median follow-up of 6.4 years, OS for all patients was significantly worse for those who received ZA (HR 0.468, 95% CI 0.226-0.967, P = 0.040). DFS was not significantly different between the treatment arms (HR 0.656, 95% CI 0.371-1.160, P = 0.147). In a subgroup analysis of postmenopausal women, no significant difference in DFS or OS was found for those who received ZA compared with the control group (HR 0.464, 95% CI 0.176-1.222, P = 0.120; HR 0.539, 95% CI 0.228-1.273, P = 0.159, respectively). The subgroup analysis of premenopausal patients was not significantly different for DFS and OS ((HR 0.798, 95% CI 0.369-1.725, P = 0.565; HR 0.456, 95% CI 0.156-1.336, P = 0.152, respectively). Baseline IGF-1R expression was not significantly associated with DFS or OS. In a predefined additional study, lower serum levels of insulin were associated with improved DFS (HR 1.025, 95% CI 1.005-1.045, P = 0.014).

CONCLUSIONS

Our results suggest that ZA in combination with neoadjuvant chemotherapy was associated with a worse OS in breast cancer (both pre- and postmenopausal patients). However, in a subgroup analysis of postmenopausal patients, ZA treatment was not associated with DFS or OS. Also, DFS was not significantly different between both groups. IGF-1R expression in tumor tissue before and after neoadjuvant treatment did not predict survival.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01099436 , April 2010.

Insulin-like growth factor 1 receptor expression and IGF1R 3129G > T polymorphism are associated with response to neoadjuvant chemotherapy in breast cancer patients: results from the NEOZOTAC trial (BOOG 2010-01)

Background

The insulin-like growth factor 1 (IGF-1) pathway is involved in cell growth and proliferation and is associated with tumorigenesis and therapy resistance. This study aims to elucidate whether variation in the IGF-1 pathway is predictive for pathologic response in early HER2 negative breast cancer (BC) patients, taking part in the phase III NEOZOTAC trial, randomizing between 6 cycles of neoadjuvant TAC chemotherapy with or without zoledronic acid.

Methods

Formalin-fixed paraffin-embedded tissue samples of pre-chemotherapy biopsies and operation specimens were collected for analysis of IGF-1 receptor (IGF-1R) expression (n = 216) and for analysis of 8 candidate single nucleotide polymorphisms (SNPs) in genes of the IGF-1 pathway (n = 184) using OpenArray® RealTime PCR. Associations with patient and tumor characteristics and chemotherapy response according to Miller and Payne pathologic response were performed using chi-square and regression analysis.

Results

During chemotherapy, a significant number of tumors (47.2 %) showed a decrease in IGF-1R expression, while in a small number of tumors an upregulation was seen (15.1 %). IGF-1R expression before treatment was not associated with pathological response, however, absence of IGF-1R expression after treatment was associated with a better response in multivariate analysis (P = 0.006) and patients with a decrease in expression during treatment showed a better response to chemotherapy as well (P = 0.020). Moreover, the variant T allele of 3129G > T in IGF1R (rs2016347) was associated with a better pathological response in multivariate analysis (P = 0.032).

Conclusions

Absent or diminished expression of IGF-1R after neoadjuvant chemotherapy was associated with a better pathological response. Additionally, we found a SNP (rs2016347) in IGF1R as a potential predictive marker for chemotherapy efficacy in BC patients treated with TAC.

Trial registration

ClinicalTrials.gov NCT01099436. Registered April 6, 2010.

Improved Circulating Tumor Cell Detection by a Combined EpCAM and MCAM CellSearch Enrichment Approach in Patients with Breast Cancer Undergoing Neoadjuvant Chemotherapy

Circulating tumor cells (CTC) are detected by the CellSearch System in 20% to 25% of patients with primary breast cancer (pBC). To improve CTC detection, we investigated melanoma cell adhesion molecule (MCAM) as enrichment marker next to epithelial cell adhesion molecule (EpCAM) and tested the clinical relevance of MCAM-positive CTCs in patients with HER2-negative stage II/III pBC starting neoadjuvant chemotherapy (NAC) in the NEOZOTAC trial. Using the CellSearch System, EpCAM-positive and MCAM-positive CTCs were separately enriched from 7.5 mL blood, at baseline and after the first NAC cycle. Circulating endothelial cells (CEC) were measured using flow cytometry. Primary objective was to improve the CTC detection rate to ≥ 40% combining EpCAM/MCAM. Correlations of CTC and CEC counts and pathologic complete response (pCR) were also explored. At baseline, we detected EpCAM-positive and MCAM-positive CTCs in 12 of 68 (18%) and 8 of 68 (12%) patients, respectively. After one cycle, this was 7 of 44 (16%) and 7 of 44 (16%) patients, respectively. The detection rate improved from 18% at baseline and 16% after one cycle with EpCAM to 25% (P = 0.08) and 30% (P = 0.02), respectively, with EpCAM/MCAM. No patients with MCAM-positive CTCs versus 23% of patients without MCAM-positive CTCs at baseline achieved pCR (P = 0.13). EpCAM-positive CTCs and CEC counts were not correlated to pCR. Combined EpCAM/MCAM CellSearch enrichment thus increased the CTC detection rate in stage II/III pBC. We found no associations of CTC and CEC counts with pCR to NAC. The clinical relevance of MCAM-positive CTCs deserves further study.

A combined EpCAM and MCAM circulating tumor cell (CTC) CellSearch enrichment to improve CTC capture rate in stage II/III breast cancer: A Dutch Breast Cancer Trialists' Group (BOOG) side study

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Background: Using the CellSearch System (Veridex, USA), ≥1 CTC/7.5 mL of peripheral blood is found in ~20% of primary breast cancer (BC) patients. However, epithelial cell adhesion molecule (EpCAM)-negative CTCs may be missed. We previously showed that a subset of BC cell lines lacks EpCAM, but does express melanoma cell adhesion molecule (MCAM) and that MCAM-positive CTCs (M-CTCs) do occur in metastatic breast cancer patients. In a side-study of the NEOZOTAC trial, a randomized study comparing neoadjuvant chemotherapy (NAC) with or without zoledronic acid in stage II/III BC, we investigated whether combined enrichment with EpCAM and MCAM increases the CTC detection rate. Besides, we hypothesized that CTC counts would correlate with pathological complete response (pCR) to NAC. Additionally, as exploratory study, circulated endothelial cells (CECs) were measured. Methods: At baseline and after the 1st chemotherapy cycle, blood was drawn from all patients in the NEOZOTAC trial who gave additional informed consent. The CellSearch System was used to count EpCAM-positive CTCs (E-CTCs) and M-CTCs. For the latter, the anti-EpCAM-ferrofluid was replaced by an anti-MCAM-ferrofluid (both Veridex). CECs were measured using flow cytometry. Results: At baseline, blood was received from 73 patients; ≥1 E-CTCs and M-CTCs were detected in 14/73 (19%, median 1) and 8/68 (12%, median 1), respectively. Combining both counts, ≥1 CTCs were detected in 17/68 (25%) of patients (p=0.01). After 1 chemotherapy cycle, E-CTCs, M-CTCs and overall CTCs were detected in 9/47 (19%), 7/45 (16%), and 13/44 (30%; p<0.01) patients. Median CEC count was 43 at baseline and 142 after cycle 1 (p<0.001). No differences in CTC and CEC count were found between the treatment arms. Baseline CTC counts, nor changes in counts, were associated with pCR. Conclusions: Combined enrichment of CTCs with EpCAM and MCAM significantly increased CTC detection rates in stage II/III BC with about 10%. CTC counts were not associated with pCR to NAC. Associations with disease free survival will follow when available.

NEOZOTAC: Efficacy results from a phase III randomized trial with neoadjuvant chemotherapy (TAC) with or without zoledronic acid for patients with HER2-negative large resectable or stage II or III breast cancer (BC)—A Dutch Breast Cancer Trialists’ Group (BOOG) study

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Background: The role of bisphosphonates when added to the neoadjuvant treatment of BC in enhancing the efficacy of therapy is still unknown. Methods: NEOZOTAC is a national, multicenter, randomized study comparing the efficacy of TAC (docetaxel, Adriamycin and cyclophosphamide i.v.) CT followed by G-CSF on day 2 with or without ZA 4 mg i.v. ,q 3 weeks in patients (pts) with stage II/III, measurable, HER2-negative BC and absence of prior bisphosphonate usage. The primary endpoint is the pathologic complete response (pCR) rate in the resection specimen and positive lymph nodes. 228 pts are needed to show an improvement of the pCR rates from 17% to 34% in the experimental arm using a 5% significance level based on the two-sided Fisher’s exact test with a power of 80%. Randomization was done by using the Pocock’s minimisation technique stratified by cT, cN and estrogen receptor status. pCR rate was analyzed using the Cochran-Mantel-Haenszel test, adjusting for the stratification factors. Analysis was based on intent-to-treat. An unplanned subgroup analysis of postmenopausal women (PMW; FSH >20 and estradiol <110) and baseline vitamin D levels was performed. Results: From July 2010 to April 2012, 250 patients from 25 participating sites were randomized. Pathologic response data of 228 patients are currently available. pCR rate did not differ between the two study arms (17% vs 16%, p = 0.81). However, a trend in benefit in favor of ZA was observed in PMW (18% vs 11%, OR 1.90, 95% C.I. 0.52 – 6.88). Patients with severe vitamin D insufficiency (<25 nmol/L) seemed to respond worse to CT numerically (6% vs. 18%). At ASCO pCR and clinical response data of all patients will be reported. Conclusions: Previously, we have shown that adding ZA to neoadjuvant CT is safe with good compliance.In this study, treatment with ZA did not result in a pCR benefit in the total study population. However our findings suggest that addition of ZA to neoadjuvant CT might be effective for enhancing response in PMW with BC. Clinical trial information: NCT01099436.

[Antitumour effects of bisphosphonates in breast cancer]

Pre-clinical and clinical studies increasingly suggest that the most potent nitrogen-containing bisphosphonates have antitumour effects. Bisphosphonates inhibit osteoclast-mediated bone resorption, and can thus delay the spread of skeletal metastases. Bisphosphonates might also inhibit tumour growth outside the skeleton by inducing apoptosis and inhibiting proliferation, adhesion, invasion, and angiogenesis of tumour cells. Recent trials suggest a possible synergistic antitumour effect between bisphosphonates and chemotherapy. A mechanism of action for bisphosphonates that could explain their possible antitumour effect and their synergy with chemotherapy is speculative and demands further investigation. The role of bisphosphonates in primary neoadjuvant treatment of breast cancer is promising, but must be further investigated.