Indication and perspectives of radiation therapy in the setting of de-novo metastatic prostate cancer

Prostate cancer is the most common cancer and the third leading cause of cancer mortality in men. Each year, approximately 10% of prostate cancers are diagnosed metastatic at initial presentation. The standard treatment option for de-novo metastatic prostate cancer is androgen deprivation therapy with novel hormonal agent or with chemotherapy. Recently, PEACE-1 trial highlighted the benefit of triplet therapy resulting in the combination of androgen deprivation therapy combined with docetaxel and abiraterone. Radiotherapy can be proposed in a curative intent or to treat local symptomatic disease. Nowadays, radiotherapy of the primary disease is only recommended for de novo low-burden/low-volume metastatic prostate cancer, as defined in the CHAARTED criteria. However, studies on stereotactic radiotherapy on oligometastases have shown that this therapeutic approach is feasible and well tolerated. Prospective research currently focuses on the benefit of intensification by combining treatment of the metastatic sites and the primary all together. The contribution of metabolic imaging to better define the target volumes and specify the oligometastatic character allows a better selection of patients. This article aims to define indications of radiotherapy and perspectives of this therapeutic option for de-novo metastatic prostate cancer.

Radiation therapy of the primary tumour and/or metastases of digestive metastatic cancers

Metastatic gastrointestinal cancer is not an uncommon situation, especially for pancreatic, gastric, and colorectal cancers. In this setting, few data are available on the impact of the treatment of the primary tumour. Oligometastatic disease is associated with longer survival in comparison with more advanced disease. Metastasis-directed therapy, such as stereotactic body radiotherapy, seems related to better outcomes, but the level of evidence is low. In most tumour locations, prospective data are very scarce and inclusion in ongoing trials is strongly recommended.

Stereotactic body radiation therapy for liver metastases in oligometastatic disease

Oligometastatic cancers designate cancers in which the number of metastases is less than five, corresponding to a particular biological entity whose prognosis is situated between a localized and metastatic disease. The liver is one of the main sites of metastases. When patients are not suitable for surgery, stereotactic body radiotherapy provides high local control rate, although these data come mainly from retrospective studies, with no phase III study results. The need for a high therapeutic dose (biologically effective dose greater than 100Gy) while respecting the constraints on the organs at risk, and the management of respiratory movements require expertise and sufficient technical prerequisites. The emergence of new techniques such as MRI-guided radiotherapy could further increase the effectiveness of stereotactic radiotherapy of liver metastases, and thus improve the prognosis of these oligometastatic cancers.

[Predictive factors assessment of pathological response to neoadjuvant radiotherapy of soft tissue sarcomas]

PURPOSE

Conserving surgery combined with radiotherapy in presence of local recurrence risk factors is standard treatment of soft tissue sarcomas, a group of rare and heterogeneous tumours. Radiotherapy is performed before or after surgery. In neoadjuvant setting, late radiation-induced toxicity is reduced and pathological response to radiotherapy could be achieved. A complete pathological response to radiotherapy has recently been shown to predict better survival. Our study aims at identifying predictive factors of pathological response to neoadjuvant radiotherapy (clinical, radiological or histological) of soft tissue sarcomas.

PATIENTS AND METHODS

Clinical, imaging (MRI: perilesional oedema, necrosis, tumour heterogeneity, vasculonervous relationships) and pathological (pathological subtype, tumour grade, anticipated/obtained resection quality) data were retrospectively collected. Tumour response (imaging and pathological), patient outcome, acute and late radiation-induced toxicity, predictive factors of pathological response to neoadjuvant radiotherapy were studied. The 2-test or exact-Fisher test (qualitative variables) and by Student's t-test or Kruskal-Wallis test (quantitative variables) were used for statistical analysis.

RESULTS

From April 2017 to April 2021, neoadjuvant radiotherapy (50Gy in 25 fractions) followed by surgical excision was performed to 36 consecutive patients with liposarcomas (n=17/36), or undifferentiated sarcomas (n=8/36). MRI response was complete in 1 patient, partial in 9 patients (n=9/36, 25%), stable in 21 patients (n=21/36, 58%) or in progression in 5 patients (n=5/36, 14%). Pathological response was observed in 22 patients (61%). No grade 3-4 acute radiation-induced toxicity was observed. Regarding late toxicity, 28% of patients had grade 1-2 oedema (n=10/36), 39% had a grade 1 fibrosis (n=14/36), and 30% grade 1 pain (n=11/36). No predictive factors of response to radiotherapy was statistically significant.

CONCLUSIONS

Neoadjuvant radiotherapy is well-tolerated. No clinical, radiological or pathological predictive factors was identified for radiotherapy tumour response.

[Stereotactic Body Radiation Therapy for less than 3cm (stage I) and 5cm (stage II) inoperable lung tumors: 10 years experience of Montpellier Cancer Institute]

PURPOSE

Search for predictive factors on survival and local control for less than 3 centimeters (cm) (stage I) and 5cm (stage II) inoperable lung tumors treated by Stereotactic Body Radiation Therapy (SBRT) in a retrospective monocentric study from Montpellier Cancer Institute (ICM) PATIENTS AND METHOD: Every patients treated at ICM for a stage I or II inoperable lung tumors from 2009 to 2019 were analyzed.

RESULTS

One hundred and seventy nine lesions were treated in 176 patients, with a major part (82,7%) in operated due to chronic obstructive pulmonary disease. Median overall survival for all patients was 71,7 months with a 35 months follow-up and the 2 years loco-regional free survival was 94,0 months. Better associated outcomes were stage I (median overall survival 71,7 versus 29,0 months P=0,004 ; HR=2,37 P=0,005), BED≥150Gy (median time-to-progression not reached versus 76,7 months P=0,025), small size of Planning Target Volume (PTV) (HR=0,42 P=0,032 when PTV<15,6 cc). 7,3% of all patients developed radiation pneumonitis.

CONCLUSION

SBRT is associated with an excellent overall survival and a high rate of local control for less than 3cm (stage I) and 5cm (stage II) lung tumors but a low rate of toxicities. For these patients with many comorbidities, BED over 150Gy seems to be associated with a better loco-regional free survival, while cause of death is often other than lung cancer.

Acceptance, commissioning and quality assurance of the MRIdian®: Site experience and three years follow-up

PURPOSE

This study presents the methodology and results of the acceptance and periodical quality controls on the MRIdian®.

MATERIALS AND METHODS

The impact of the magnetic field on other machines was investigated by controlling nearby linacs dose profiles. The image quality of the 0.345T MR scanner was evaluated, also assessing the integrated linear accelerator influence. The photon beams lateral and depth dose profiles were measured in motorized water tanks, along dose rate and output factors, and compared to Monte Carlo (MC) calculations. The isocenter position, gantry angles and multi-leaf collimator (MLC) position were controlled using film dosimetry. Gating latency and dosimetric accuracy were controlled with a dynamic phantom.

RESULTS

The magnetic field had no significant impact on other nearby linacs. Image quality was within tolerances and did not vary over time. Dose profiles measured showed good agreement with MC data, with maximum differences of 1.3% in-field. Output factors were within 0.8% of calculated values. Imaging and radiative isocenter matched within 0.9±0.4mm over all monthly controls. Gantry rotation was precise within -0.1±0.2°, with an isocenter variation of 1.4±0.3mm diameter. The average MLC position was within 0.4±0.1mm of theoretical value. Finally, the gating latency was 0.14±0.07sec and the gated dose within 0.3% of base value.

CONCLUSION

All results are within the tolerances fixed by ViewRay® and show low variations over 2 years, comforting the use of small margins and gating for high-dose adaptive treatments.

News in magnetic resonance imaging use for radiation oncology

The purpose of this article is to give a summary of the progress of magnetic resonance imaging (MRI) in radiotherapy. MRI is an important imaging modality for treatment planning in radiotherapy. However, the registration step with the simulation scanner can be a source of errors, motivating the implementation of all-MRI simulation methods and new accelerators coupled with on-board MRI. First, practical MRI imaging for radiotherapy is detailed, but also the importance of a coherent imaging workflow incorporating all imaging modalities. Second, future evolutions and research domains such as quantitative imaging biomarkers, MRI-only pseudo computed tomography and radiomics are discussed. Finally, the application of MRI during radiotherapy treatment is reviewed: the use of MR-linear accelerators. MRI is increasingly integrated into radiotherapy. Advances in diagnostic imaging can thus benefit radiotherapy, but specific radiotherapy constraints lead to additional challenges and require close collaboration between radiologists, radiation oncologists, technologists and physicists. The integration of quantitative imaging biomarkers in the radiotherapy process will result in mutual benefit for diagnostic imaging and radiotherapy. MRI-guided radiotherapy has already been used for several years in clinical routine. Abdominopelvic neoplasias (pancreas, liver, prostate) are the preferred locations for treatment because of their favourable contrast in MRI, their movement during irradiation and their proximity to organs at risk of radiation exposure, making the tracking and daily adaptation of the plan essential. MRI has emerged as an increasingly necessary imaging modality for radiotherapy planning. Inclusion of patients in clinical trials evaluating new MRI-guided radiotherapy techniques and associated quantitative imaging biomarkers will be necessary to assess the benefits.

Role of radiotherapy in the management of bladder cancer: Recommendations of the French society for radiation oncology

We present the recommendations of the French society of oncological radiotherapy on the indications and techniques for external beam radiotherapy for bladder cancer.

Tumour and normal tissue radiosensitivity

The place of personalized treatments is highly increasing in medical and radiation oncology. During the last decades, a huge number of assays have been developed to predict responses of normal tissues and tumours. These tests have not yet been included into daily clinical practice but the recent developments of radiation oncology are paving the way of personalized strategies including the risk of tumour recurrence and normal tissue reactions. Concerning tumor radiosensitivity prediction, no test are currently used, even if the radiosensitivity index and the genome-based model for adjusting radiotherapy dose assays seem the most promising with level II of evidence. Commercial developments are under progress. Concerning normal tissue radiosensitivity prediction, single nucleotide polymorphims of prostate cancer patients and radiation-induced CD8 T-lymphocyte apoptosis breast and prostate assays are of level I of evidence. They can be proposed before the beginning of radiotherapy in order to propose personalized treatments according to both risks of tumour and normal tissue radiosensitivity. Commercial developments are also under way.

[Stereotactic body radiotherapy for liver tumors: State of the art]

Thanks to the improvement in radiotherapy physics, biology, computing and imaging, patients presenting with liver tumors can be efficiently treated by radiation. Radiotherapy has been included in liver tumors treatment guidelines at all disease stages. Liver stereotactic radiotherapy has to be preferred to standard fractionated radiotherapy whenever possible, as potentially more efficient because of higher biological equivalent dose. Liver stereotactic radiotherapy planning and delivery require extensive experience and optimal treatment quality at every step, thus limiting its availability to specialized centres. Multicentre studies are difficult to develop due to a large technical heterogeneity. Respiratory management, image guidance and immobilization are considerations as important as machine type. The use of multimodal planning imaging is compulsory to achieve expected contouring quality. Treatment efficacy is difficult to assess following liver stereotactic radiotherapy, but local control is high and toxicity unusual. As a consequence, liver stereotactic radiotherapy is part of multimodal and multidisciplinary management of liver tumors.

Abstract P3-12-18: Radiation-induced CD8 T-lymphocyte apoptosis as a predictor of late toxicity after radiotherapy: Results of the prospective multicenter French trial

Purpose/Objective(s): We and others showed in retrospective and monocentric studies that radiation-induced CD8-lymphocyte apoptosis (RILA) can significantly predict differences in late toxicity between individuals and can be used as a rapid screening for potential hyper-reactive patients to radiation therapy (RT). We present here the clinical results of the prospective multicenter French trial (NCT00893035) evaluating the predictive role of RILA as a predictor of late effects after RT.

Materials/Methods: A total of 502 consenting breast-cancer patients (pts) treated by conservative surgery and adjuvant RT were included by 10 French centers. Lymphocytes apoptosis was assessed before RT by associated condensation of DNA. The incidence of late toxicities was obtained using CTCAEv3.0 grading scale. Complication-free survival (CFS) and complication-relapse-free survival (CRFS) curves were estimated by the Kaplan-Meier method. The log-rank test was used to identify significant categorical variables for each of the survival curves. Cox model was used for multivariate analysis.

Results: Four hundred and fifty-four pts (90.4%) were included in the final analysis (clinical, biological and dosimetric data available). One hundred and eight pts (24%) received both whole breast (WB) and nodal irradiation (NI). A boost dose of 10-16 Gy was given in 448 pts (99%). Adjuvant hormonotherapy (tamoxifen or aromatase inhibitor) was delivered to 346 pts (76%). Three categories of absolute change in the percent CD8 cells in apoptosis before and after exposure to 8-Gy in vitro RT were constructed around the 33 percent quantiles, &lt;12%, 12-20%, and &gt;20%. In a median follow-up period of 38.5 months, grade 2 and 3 late fibrosis was observed in 54 (12%) and 3 (0.7%) pts, respectively. A decreased percentage of grade 2 or more late toxicity was observed for increasing values of CD8 apoptosis (p=0.001). No grade 3 late toxicity was observed for patients with RILA ≥12%. The 3-year CFS rates were significantly lower for patients with low levels of CD8 radiation-induced apoptosis, 79% (95% confidence interval [CI]: 72–85%), 90% (95% CI: 84–94%), and 93% (95% CI: 87–96%) for CD8 &lt;12%, 12–20%, and &gt;20%, respectively (p=0.001). Similar results were observed for the CRFS rates (p&lt;0.001). In multivariate analyses, prognostic factors for CFS were RILA&lt;12% (p=0.001), smoking history (p&lt;0.001), and adjuvant hormonal treatment (p=0.008). Negative predictive value for grade 2 or more toxicity was equal to 83% for CD8 &gt;20% and positive predictive value was equal to 22% for CD8 &lt;12% where the overall prevalence of grade 2 or more late side effects was estimated at 14%.

Conclusion: RILA significantly predicts differences in radiation-induced late toxicity between individuals. This study validates the use of RILA as a rapid screening for potential hyper-reactive pts to radiotherapy.

Citation Format: Hennequin C, Azria D, Riou O, Castan F, Coelho M, Nguyen TD, Peignaux K, Lemanski C, Lagrange J-L, Kirova Y, Lartigau E, Belkacemi Y, Bourgier C, Noel G, Clippe S, Mornex F, Kramar A, Pèlegrin A, Ozsahin M. Radiation-induced CD8 T-lymphocyte apoptosis as a predictor of late toxicity after radiotherapy: Results of the prospective multicenter French trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-12-18.

[Radiosensitivity settings in breast cancer]

Breast cancers are highly radiosensitive since the risk of recurrences and of mortality after adjuvant radiotherapy following breast-conserving surgery is decreased by 15.7% and 3.8%, respectively at 10 years. The total dose if irradiation also significantly increases local control: a boost of 16 Gy to the tumour bed after breast-conserving surgery reduces the absolute risk of recurrence by 4% at 10 years. Breast cancers are sensitive to the dose per fraction, as shown by the results from four randomized trials which compared standard irradiation (50 Gy/25 fractions) with a hypofractionated scheme: no statistical difference was observed in locoregional recurrence and overall survival at 10 years. The α/β ratio, which reflects the dose per fraction and is theoretically over 10 Gy for tumour tissues, has been estimated between 2.2 and 4.4 Gy for breast cancers. Molecular abnormalities, such as overexpression of HER1 (especially in triple negative breast cancer) and HER2, induce a higher radioresistance. In vitro studies showed that targeted therapies, which block these receptors, increase breast cancer radiosensitivity. Tumour stem cells have been identified in breast cancers and are characterized by a higher radioresistance. This radioresistance could be related to a better repair of radiation-induced DNA damages and a decrease of reactive oxygen species (ROS), which are involved in their occurrence. In the future, a better understanding of genetics tumour abnormalities will allow to identify new radiosensitivity settings in breast cancers.

[Stereotactic body radiation therapy and oligometastases]

In stage IV cancers, locoregional management of primitive tumours as surgery and/or radiotherapy improved both progression-free survival and overall survival. Among metastatic cancer patients, some of them are considered as oligometastatic stage as they present few metastatic sites associated with low tumor aggressiveness. For those patients, metastatic local control, and therefore prolonged time to progression should be reached through local treatments as surgery and/or radiofrequency ablation and/or stereotactic radiotherapy. Here we propose a review of oligometastatic stage and results from extracranial stereotactic radiotherapy in terms of efficacy and tolerance.

Retroperitoneal sarcomas: patterns of care in advanced stages, prognostic factors and focus on main histological subtypes: a multicenter analysis of the French Sarcoma Group

BACKGROUND

Retroperitoneal sarcomas (RPS) are heterogeneous. Advanced stages include unresectable locoregional (LR) disease, abdominal sarcomatosis and distant metastasis. There is no available report assessing palliative chemotherapy in advanced RPS. This study analyzes management and outcome in a large cohort of patients with advanced RPS, considering main histological subtypes separately.

PATIENTS AND METHODS

We conducted a retrospective analysis of adult patients diagnosed with a RPS between 1 January 1988 and 31 December 2008 across 12 centers of the French Sarcoma Group. All cases were centrally reviewed by an expert pathologist.

RESULTS

Five-hundred eighty-six patients were included, 299 patients received palliative chemotherapy, with a median of two lines (range 0-8). Fifty patients underwent palliative surgery. Two hundred fifty-five patients (85%) were assessable for response after first line of chemotherapy. Among them, 69 patients (27%) had progressive disease, 145 (57%) had stable disease, 37 (14.5%) had partial response and 4 (1.5%) complete response. Median time from first line of palliative chemotherapy to progression was 5.9 months [4.9-7.3] and median overall survival (OS), 15.8 months [13-18]. In multivariate analysis, prognosis factors independently associated with poor OS were male gender, performance status (PS) >1 and grade >1. There was no difference according to stage of disease. Palliative surgery did not appear to add any survival benefit.

CONCLUSION

These results emphasize the scarcity of available options for RPS in the advanced setting and the urgent need to develop new strategies. Patients with good PS should be included in clinical trials and best supportive care should be considered in those with poor PS.

Retroperitoneal sarcomas: patterns of care at diagnosis, prognostic factors and focus on main histological subtypes: a multicenter analysis of the French Sarcoma Group

BACKGROUND

Retroperitoneal sarcomas (RPS) are heterogeneous. No previous study has investigated the impact of specialized surgery, evaluated locoregional relapse (LRR), abdominal sarcomatosis and distant metastatic relapse as separate events, or considered histological subtypes separately. This study addresses these specific points in a homogeneous cohort of patients with completely resected primary RPS.

PATIENTS AND METHODS

We conducted a retrospective analysis of adult patients diagnosed with a RPS between 1 January 1988 and 31 December 2008 and eventually referred to one of 12 centers of the French Sarcoma Group. All cases were centrally reviewed by an expert pathologist.

RESULTS

Five hundred eighty-six patients were included. Median follow-up was 6.5 years [95% confidence interval (CI) 5.9-7.1]. Five hundred thirty-seven patients had localized disease and 389 patients (76%) had macroscopically complete resection of the tumor. In this latter group, the 5-year LRR-free survival rate was 46% [41-52] and the 5-year overall survival (OS) rate was 66% [61-71]. In multivariate analysis, gender, adjacent organ involvement, specialization of the surgeon, piecemeal resection and perioperative radiotherapy were independently associated with LRR. Specialization of the surgeon and piecemeal resection were independently associated with abdominal sarcomatosis whereas histology and adjacent organ involvement were independently associated with distant metastasis. Age, gender, grade, adjacent organ involvement and piecemeal resection were significantly associated with OS. Prognostic factors for LRR and OS were analyzed in well-differentiated and dedifferentiated liposarcomas and leiomyosarcomas. Grade 3 was an independent prognostic factor for OS of dedifferentiated liposarcomas.

CONCLUSION

This study underlines the crucial role of pretherapeutic assessment and meticulous histological examination of RPS as well as the need to consider histological subtypes separately. Surgery in a specialized center and avoidance of piecemeal resection stand out as the two most important prognostic factors for RPS and highlight the importance of treating these patients in specialized centers.

[Hypofractionated radiotherapy, a standard in breast cancer?]

In the era of high-tech radiotherapy, hypofractionated schema is more and more widely used regardless of tumour sites. In this article, we expose the role, techniques and indications of hypofractionated radiotherapy in adjuvant breast radiotherapy.