A phase I study of the combination of atezolizumab, tiragolumab, and stereotactic body radiation therapy in patients with metastatic multiorgan cancer

BACKGROUND

Immunotherapy targeting the PD-1/PD-L1 pathway is a standard of care in a number of metastatic malignancies, but less than a fifth of patients are expected to respond to ICIs (Immune Checkpoint Inhibitors). In a clinical trial, combining the anti-TIGIT (T cell immunoreceptor with Ig and ITIM domains) Mab (monoclonal antibody) tiragolumab with atezolizumab improved outcomes in non-small cell lung cancer. In preclinical models, SBRT (Stereotactic Body Radiation Therapy) could increase expression levels of the inhibitory co-receptors TIGIT and PD-L1. We aim to assess the combination of tiragolumab with atezolizumab and SBRT in metastatic, previously treated by ICIs, non-small cell lung cancer, head and neck cancer, bladder cancer, and renal cell cancer.

METHODS

This phase I study (ClinicalTrials.gov NCT05259319) will assess the efficacy and safety of the combination of atezolizumab with tiragolumab and stereotactic body radiation therapy in patients with histologically proven metastatic non-small cell lung cancer, renal cell cancer, bladder cancer, and head and neck cancer previously treated. First part: 2 different schedules of SBRT in association with a fixed dose of atezolizumab and tiragolumab will be investigated only with metastatic non-small cell lung cancer patients (cohort 1). The expansion cohorts phase will be a multicentric, open-label study at the recommended scheme of administration and enroll additional patients with metastatic bladder cancer, renal cell cancer, and head and neck cancer (cohort 2, 3 and 4). Patients will be treated until disease progression, unacceptable toxicity, intercurrent conditions that preclude continuation of treatment, or patient refusal in the absence of progression or intolerance. The primary endpoint of the first phase is the safety of the combination in a sequential or concomitant scheme and to determine the expansion cohorts phase recommended scheme of administration. The primary endpoint of phase II is to evaluate the efficacy of tiragolumab + atezolizumab + SBRT in terms of 6-month PFS (Progression-Free Survival). Ancillary analyses will be performed with peripheral and intratumoral immune biomarker assessments.

TRIAL REGISTRATION

This study is registered on ClinicalTrials.gov: NCT05259319, since February 28th, 2022.

Intra Fraction Organs at Risk Movements in Adaptive Radiotherapy of Upper-Abdominal Stereotactic Body Radiotherapy on 0.35 T MR-Linac

PURPOSE/OBJECTIVE(S)

The recent development of magnetic resonance guided radiotherapy (MRgRT) has made possible adaptive radiotherapy (ART) especially for abdominal stereotactic body radiotherapy (SBRT). Online ART process allows to adapt the treatment at each fraction by considering the mobility of the organs at risk (OAR) and the target. These volumes are daily delineated and a new treatment plan is reoptimized. This process is multidisciplinary involving therapists, physicians and physicists. Time is a key element because of the presence of the patient on the treatment couch. In spite of having a well-trained team, the fraction duration is quite long, usually equal or higher than 45 min. Consequently, the elapsed time between the acquisition of the MR images used for the ART process and the end of the treatment delivery can be substantial. In this context, we decided to investigate the intra fraction OAR mobility by analyzing and comparing two images of the MR-Linac: one acquired at the beginning of the fraction and used for the ART process and another one immediately acquired at the end of the treatment delivery. The objectives of this study are to investigate the OAR mobility during the fraction and evaluate the possible impact on the dose distribution.

MATERIALS/METHODS

Twenty patients treated in 5 fractions for upper-abdominal SBRT (liver, adrenal, pancreas, adenopathy) on the 0.35 T MR-Linac of our institution have been prospectively included in this study between May 2021 and August 2021. For each fraction an additional 3D MR image has been acquired immediately at the end of the treatment delivery. The OARs (colon, small bowel and duodenum) included in the ART process have been delineated on the post-fraction images. After having registered both images of each fraction, OAR volumes and their dose distributions have been compared.

RESULTS

A high level of mobility of several OARs has been observed. For instance, a relative mean volume variation (increase or diminution) of 85%, 60% and 24% have been calculated, respectively, for the small bowel, the colon and duodenum. These level of volume variations strongly impacted the OAR dose distributions. For instance, the variation (increase or diminution) of maximum dose for colon, small bowel and duodenum was, respectively, about 4.3 Gy, 3.4 Gy and 2.8 Gy. These modifications led to exceed dose constraints in 2 fractions for colon, 4 fractions for small bowel and 3 fractions for duodenum. Nevertheless, by accumulating all the fractions, the dose constraints were always satisfied.

CONCLUSION

OARs volume modifications during ART process can be significant and lead to important dose variations. At the scale of the treatment, these dose variations respect the dose constraints. In the near future, the correlation of these volumetric variations with the duration of the fraction will be investigated.

[Dose optimization in 3D pulsed dose rate brachytherapy for patients with locally advanced cervical cancer: A French multicenter phase II trial]

PURPOSE

We present the results of the PHRC Tridicol, a prospective French phase II study whose objective was to increase the dose delivered to the target volume during brachytherapy for locally advanced cervical cancers.

MATERIAL AND METHODS

Eight centers included 48 patients, treated with concomitant radiochemotherapy, then uterovaginal brachytherapy.

RESULTS

The median follow-up was 63 months. The dose of brachytherapy delivered in biological equivalent dose (EQD2) to 90% of the High Risk CTV (D90 CTV HR) was 80Gy in median dose. The 5-year local control rate (LC) was 84%, close to the hypothesis of 86.7%. The rate of severe complications (grade 3-4) was 23% at 5 years. The rectal dose was correlated with the risk of severe complications.

CONCLUSION

HR CTV dose was below the target (85Gy) due to low use of parametrial interstitial needles, as the centers did not always have an adequate applicator, or were at the time at the beginning of their learning curve. The 5-year LC rate was improved compared to that of the comparable STIC PDR group (78%) but lower than the retroEMBRACE cohort of GEC ESTRO (89%). The complication rate was higher than in the comparable group of STIC PDR but close to that of retroEMBRACE. Training brachytherapy teams in interstitial implantation or referring patients to referral centers should help improve the therapeutic index of cervical cancer.

Cisplatin-based chemoradiation decreases telomerase-specific CD4 TH1 response but increases immune suppressive cells in peripheral blood

Background

The synergistic effect of chemoradiation (CRT) has been previously demonstrated in several cancer types. Here, we investigated the systemic immune effects of CRT in patients with lung or head and neck cancer.

Materials and methods

Peripheral blood mononuclear cells were collected at baseline and 1 month after treatment from blood samples of 29 patients treated with cisplatin-based chemoradiotherapy for lung or head and neck cancer. Circulating anti-tumor Th1 response was assessed by the ELISpot assay using a mixture of human leucocyte antigen (HLA) class II restricted peptides derived from telomerase (TERT). Phenotyping of circulating immunosuppressive cells (Treg and MDSC) was performed by flow cytometry.

Results

A significant increase of circulating Treg was observed in 60% of patients after CRT The mean rate of Treg was 3.1% versus 4.9% at baseline and after CRT respectively, p = 0.0015). However, there was a no significant increase of MDSC rate after CRT. In contrast, a decrease of tumor-specific Th1 response was documented in 7 out of 10 evaluated patients. We found high frequency of pre-existing tumor-specific Th1 response among patients with objective response after CRT compared to non-responders.

Conclusion

Cisplatin-based CRT promotes expansion of Treg and decrease of circulating anti-tumor Th1 response in peripheral blood. The balance towards a sustained specific anti-tumor T-cell response appears to be associated with response to CRT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00429-5.

Phase II study of concomitant radiotherapy with atezolizumab in oligometastatic soft tissue sarcomas: STEREOSARC trial protocol

INTRODUCTION

Up to 50% of soft tissue sarcoma (STS) patients develop metastases in the course of their disease. Cytotoxic therapy is a standard treatment in this setting but yields average tumour response rates of 25% at first line and ≤10% at later lines. In oligometastatic stage, stereotactic body radiation therapy (SBRT) allows reaching high control rates at treated sites (≥80%) and is potentially equally effective to surgery in term of overall survival. In order to shift the balance towards antitumour immunity by multisite irradiation, radiation could be combined with inhibitors of the immunosuppressive pathways.

METHODS AND ANALYSIS

STEREOSARC is a prospective, multicentric, randomised phase II, designed to evaluate the efficacy of SBRT associated with immunotherapy versus SBRT only. Randomisation is performed with a 2:1 ratio within two arms. The primary objective is to evaluate the efficacy, in term of progression-free survival (PFS) rate at 6 months, of immunomodulated stereotactic multisite irradiation in oligometastatic sarcoma patients. The secondary objectives include PFS by immune response criteria, overall survival, quality-of-life evaluation and developing mathematical models of tumour growth and dissemination predictive of oligometastatic versus polymetastatic evolution. Patients will be randomised in two groups: SBRT with atezolizumab and SBRT alone. The total number of included patients should be 103.

TRIAL REGISTRATION

The trial is registered on ClinicalTrials.gov (ID: NCT03548428).

ETHICS AND DISSEMINATION

This study has been approved by Comité de Protection des Personnes du sud-ouest et outre-mer 4 on 18 October 2019 (Reference CPP2019-09-076-PP) and from National Agency for Medical and Health products Safety (Reference: MEDAECNAT-2019-08-00004_2017-004239-35) on 18 September 2019.The results will be disseminated to patients upon individual request or through media release from scientific meetings. The results will be communicated through scientific meetings and publications.

Evaluation of the quality of the information received during head and neck cancer announcement: Prospective two-center study

BACKGROUND

Providing patient with cancer with appropriate information following the disclosure of a cancer diagnosis has multiple benefits. The objective was to evaluate the quality of the information received during an announcement for head and neck cancer and to determine predictive factors.

METHODS

We conducted a prospective two-center study using self-questionnaires to assess the patient's perception of the quality of the announcement.

RESULTS

Satisfaction scores on the information provided about the overall disease were 7.7/10. The main positive predictors of quality were a satisfactory consultation setting (P = .004), assessment of pain by a physician (P = .04), physician availability (P = .003), accurate information about tumor stage, quality of information regarding the type (P < .0001) and purpose (P = .001) of treatment and its side effects (P = .006), and the interview with the oncology nurse coordinator (P < .05).

CONCLUSIONS

Patients who received the announcement of head and neck cancer perceived the information received during the pretherapeutic period as satisfactory.

P14.78 Hypofractionated stereotactic radiotherapy as a salvage therapy for recurrent high-grade gliomas: Single-center experience

BACKGROUND

The standard of care for patients with recurrent glioblastoma or grade III glioma has not yet been clearly defined and many approaches are available for salvage strategies. These include surgery, re-irradiation or systemic agents. For the treatment of High-Grade (HGG) recurrence by radiation therapy, Hypofractionated Stereotactic Radiotherapy (HFSRT) is an interesting approach because it is minimally invasive, ambulatory, short-lasting and well tolerated. The aim of this study was to evaluate the efficacy of and safety to HFSRT as alvage treatment for patients suffering from HGG relapse in our cancer center and to compare these results with the literature.

MATERIAL AND METHODS

Between March 2012 and March 2017, 32 consecutive patients (12 women, 20 men) treated in a single-center were retrospectively included included in this study.Grade III gliomas were diagnosed in 14 patients and grade IV in 18 patients. Thirty-four lesions were treated with HFSRT on LINAC. HFSRT delivered a dose of 30 Gy in six fractions of 5Gy (27 Gy in three fractions for one patient) with two or three fractions per week. The treatment plans were normalized to 100% at the isocenter, and prescribed to the 80 % isodose line. Clinical outcomes and prognostic factors were analyzed.

RESULTS

HFSRT characteristics: The median tumor volume was of 6.1 (0.1–42.2) cm3 and the median PTV was 15 (0.6–67.5) cm3. The median maximum dose, median minimum dose and median mean dose were 38.7 (32.7–42.0) Gy, 29.1 (14.0–32.4) Gy and 35.1 (31.5–37.5) Gy, respectively. Median follow-up was 20.9 months.

Median overall survival (OS) following HFSRT was 15.6 months (Median OS for patients patients with GBM and grade III glioma were 8.2 and 19.5 months, respectively; p=0.0496).

Progression-free survival (PFS) was 3.7 months (Median PFS for patients with GBM and grade III glioma were 3.6 and 4.5months, respectively; p=0.2424).

In multivariate analysis, tumor grade III (p=0.0027), an ECOG status &lt;2 at the time of reirradiation (p=0.0023) and a mean dose &gt;35 Gy (p=0.0055) significantly improved OS. A maximum reirradiation dose above 38 Gy (p=0.0179) was significantly associated with longer PFS.

Treatment was well tolerated, no acute toxicity &gt; grade 2 was observed.

During the follow-up, ten patients (31.25%) had suspected radionecrosis. In six patients, this suspicion corresponded to tumor progression. For the other patients, radionecrosis was suggested on multi-modal MRI.

CONCLUSION

HFSRT appears to be a feasible and effective salvage treatment option for recurrent high-grade gliomas, with OS of 15.6 months. Prognostic factors associated with longer OS were a good general state of health and grade III glioma. Dosimetric data suggested that the dose gradient had an impact on tumor control and indicate that a study with dose-escalation is warranted. These results need to be confirmed in a prospective study with a greater number of patients.

Hypofractionated Stereotactic Radiotherapy as a Salvage Therapy for Recurrent High-Grade Gliomas: Single-Center Experience

Background and Purpose:

The aim of this study was to investigate the survival outcomes and safety of hypofractioned stereotactic radiotherapy as a salvage treatment for recurrent high-grade glioma.

Patients and Methods:

Between March 2012 and March 2017, 32 consecutive patients (12 women, 20 men) treated in a single center were retrospectively included in this study. Grade III gliomas were diagnosed in 14 patients and grade IV in 18 patients. Thirty-four lesions were treated with hypofractionated stereotactic radiotherapy on a linear accelerator. Hypofractionated stereotactic radiotherapy delivered a median dose of 30 Gy (27-30) in 6 fractions (3-6) of 5 Gy (5-9). The treatment plans were normalized to 100% at the isocenter and prescribed to the 80% isodose line. Clinical outcomes and prognostic factors were analyzed.

Results:

Median follow-up was 20.9 months. Median overall survival following hypofractionated stereotactic radiotherapy was 15.6 months (median overall survival for patients with glioblastoma and grade III glioma was 8.2 and 19.5 months, respectively; P = .0496) and progression-free survival was 3.7 months (median progression-free survival for patients with glioblastoma and grade III glioma was 3.6 and 4.5 months, respectively; P = .2424). In multivariate analysis, tumor grade III (P = .0027), an Eastern Cooperative Oncology Group status <2 at the time of reirradiation (P = .0023), and a mean dose >35 Gy (P = .0055) significantly improved overall survival. A maximum reirradiation dose above 38 Gy (P = .0179) was significantly associated with longer progression-free survival.

Conclusion:

Hypofractionated stereotactic radiotherapy is well tolerated and offers an effective salvage option for the treatment of recurrent high-grade gliomas with encouraging overall survival. Our results suggest that the dose distribution had an impact on survival.

Limbs and trunk soft tissue sarcoma systematic local and remote monitoring by MRI and thoraco-abdomino-pelvic scanner: A single-centre retrospective study

INTRODUCTION

Soft tissue sarcomas (STS) are rare malignant tumors that require management by an expert center. Monitoring modalities are not consensual. The objective of our study is to report systematic radiological monitoring data obtained by local MRI and by thoracic-abdominal-pelvic computed tomography (TAP CT).

MATERIAL AND METHODS

113 consecutive patients managed at "Centre Georges François Leclerc, Dijon", between 2008 and 2016, for an initially localized STS were included. Patient follow-up consisted of a local MRI and a TAP CT. Follow-up exams schedule was initially every 4 months during 2 years, followed by every 6 months during 3 years and finally every year during 5 years.

RESULTS

Median follow-up time was 37.2 months [min = 2.4 - max = 111.6]. After 5 years of surveillance, local recurrence (LR) rate was 8.8% and diagnosed by imaging in 60% of cases. No deep LR was clinically found. Median LR diagnosis time was 23.9 months [min = 2.0 - max = 52.4]. 50% of patients locally treated for their LR were alive without recurrence. Metastatic recurrence (MR) rate was 31%. 42.8% had extra-pulmonary involvement and 17.1% had exclusive extrathoracic metastases. The median time to diagnosis of MR was 17.4 months [min = 2.7- max = 77.2]. High-grade tumors relapsed more (20.4%) and earlier (all before the 5th year) than low grade.

CONCLUSION

Local MRI seems particularly suitable for monitoring deep tumors. In addition, the systematic monitoring by TAP CT highlighted a limited number of cases of exclusive extrathoracic metastases. The schedule of local and remote monitoring should primarily be adjusted to tumor grade.

Clinical and dosimetric study of radiotherapy for glioblastoma: three-dimensional conformal radiotherapy versus intensity-modulated radiotherapy

BACKGROUND AND PURPOSE

We aimed to compare three-dimensional conformal radiotherapy (3D-CRT) with intensity-modulated radiotherapy (IMRT) for the treatment of glioblastoma.

MATERIALS AND METHODS

Retrospective study of 220 patients with glioblastoma, treated with 3D-CRT or IMRT, with or without surgery. Dosimetric parameters as well as clinical and survival data for the two techniques were analyzed and compared.

RESULTS

The median conformity index was 1.53 (range 0-2.69) for 3D-CRT and 1.25 (range 0.97-2.01) for IMRT, p < 10^-4. The median homogeneity index was 0.10 (range 0.03-0.32) for 3D-CRT and 0.07 (range 0.03-0.18) for IMRT, p < 10^-4. There were significantly fewer acute grade 1 and 2 neurological toxicities in the IMRT group especially for edema (1.3 versus 12.4%, p = 0.017), concentration disorders (6.6 versus 19.9%, p = 0.003) and consciousness disorders (2.6 versus 13.2%, p = 0.002) although IMRT patients had a significantly worse pre-treatment neurological status than 3D-CRT patients. Median survival was 16.0 months (range 11.9-17.8) for IMRT and 13.4 months (range 11.7-15.7) for 3D-CRT patients (p = 0.542).

CONCLUSION

IMRT improved target conformity and reduced neurological toxicities for patients with glioblastomas.