Recommendations for Post-Operative Radiotherapy after complete resection of Thymoma - a French DELPHI consensus initiative

BACKGROUND

Thymomas are rare intrathoracic malignancies that can relapse after surgery. Whether or not Post-Operative Radiotherapy (PORT) should be delivered after surgery remains a major issue. RADIORYTHMIC is an ongoing, multicenter, randomized phase 3 trial addressing this question in patients with completely R0 resected Masaoka-Koga stage IIb/III thymoma. Experts in the field met to develop recommendations for PORT.

METHODS

A scientific committee from the RYTHMIC network identified key issues regarding the modalities of PORT in completely resected thymoma. A DELPHI-method was used to question 24 national experts, with 115 questions regarding: 1/ Imaging techniques, 2/ Clinical Target Volume (CTV) and margins, 3/ Dose constraints to Organs At Risk, 4/ Dose and fractionation, 5/ Follow-up and records. Consensus was defined when opinions reached ≥ 80% agreement.

RESULTS

We established the following recommendations: pre-operative contrast-enhanced CT-scan is recommended (94% agreement); optimization of radiation delivery includes either a 4D-CT based planning (82% agreement), a breath-holding inspiration breath-hold-based planning, or daily control CT-imaging (81% agreement); imaging fusion based on cardiovascular structures of pre-operative and planning CT-scan is recommended (82% agreement); right coronary and left anterior descending coronary arteries should be delineated as cardiac substructures (88% agreement); rotational RCMI/VMAT is recommended (88% agreement); total dose is 50Gy (81% agreement) with 1.8-2Gy per fraction (94% agreement); cardiac evaluation, and follow-up for patients with history of cardiovascular disease is recommended (88% agreement) with EKG and evaluation of LVEF at 5 years and 10 years.

CONCLUSION

This is the first consensus for PORT in thymoma. Implementation will help to harmonize practices.

Real-life clinical management patterns in extensive-stage small cell lung cancer across France: a multi-method study

BACKGROUND

We designed this study based on both a physician practice survey and real-world patient data to: (1) evaluate clinical management practices in extensive-stage small cell lung cancer (ES-SCLC) among medical centers located across France; and (2) describe first-line treatment patterns among patients with ES-SCLC following the introduction of immunotherapy into clinical practice.

METHODS

A 50-item questionnaire was completed by physicians from 45 medical centers specialized in SCLC management. Responses were collected from June 2022 to January 2023. The survey questions addressed diagnostic workup of ES-SCLC, chemoimmunotherapy in first-line and second-line settings, and use of prophylactic cranial irradiation (PCI) and radiotherapy. In parallel, using a chart review approach, we retrospectively analyzed aggregated information from 548 adults with confirmed ES-SCLC receiving first-line treatment in the same centers.

RESULTS

In ES-SCLC, treatment planning is based on chest computed tomography (CT) (as declared by 100% of surveyed centers). Mean time between diagnosis and treatment initiation was 2-7 days, as declared by 82% of centers. For detection of brain metastases, the most common imaging test was brain CT (84%). The main exclusion criteria for first-line immunotherapy in the centers were autoimmune disease (87%), corticosteroid therapy (69%), interstitial lung disease (69%), and performance status ≥ 2 (69%). Overall, 53% and 36% of centers considered that patients are chemotherapy-sensitive if they relapse within ≥ 3 months or ≥ 6 months after first-line chemoimmunotherapy, respectively. Among the 548 analyzed patients, 409 (75%) received chemoimmunotherapy as a first-line treatment, 374 (91%) of whom received carboplatin plus etoposide and 35 (9%) cisplatin plus etoposide. Overall, 340/548 patients (62%) received maintenance immunotherapy. Most patients (68%) did not receive radiotherapy or PCI.

CONCLUSIONS

There is an overall alignment of practices reflecting recent clinical guidelines among medical centers managing ES-SCLC across France, and a high prescription rate of immunotherapy in the first-line setting.

The role of radiation therapy for de novo metastatic bladder and renal cancers

Metastatic bladder and renal cancers account respectively for 2.1% and 1.8% of cancer deaths worldwide. The advent of immune checkpoint inhibitors has revolutionized the management of metastatic disease, by demonstrating considerable improvements in overall survival. However, despite initial sensitivity to immune checkpoint inhibitors for most patients, both bladder and renal cancer are associated with short progression-free survival and overall survival, raising the need for further strategies to improve their efficacy. Combining systemic therapies with local approaches is a longstanding concept in urological oncology, in clinical settings including both oligometastatic and polymetastatic disease. Radiation therapy has been increasingly studied with either cytoreductive, consolidative, ablative or immune boosting purposes, but the long-term impact of this strategy remains unclear. This review intends to address the impact of radiation therapy with either curative or palliative intent, for synchronous de novo metastatic bladder and renal cancers.

Radiotherapy in the management of lung oligometastases

In recent years, the development of both medical imaging and new systemic agents (targeted therapy and immunotherapy) have revolutionized the field of oncology, leading to a new entity: oligometastatic disease. Adding local treatment of oligometastases to systemic treatment could lead to prolonged survival with no significant impact on quality of life. Given the high prevalence of lung oligometastases and the new systemic agents coming with increased pulmonary toxicity, this article provides a comprehensive review of the current state-of-art for radiotherapy of lung oligometastases. After reviewing pretreatment workup, the authors define several radiotherapy regimen based on the localization and size of the oligometastases. A comment on the synergistic combination of medical treatment and radiotherapy is also made, projecting on future steps in this specific clinical setting.

Radiotherapy in the management of synchronous metastatic lung cancer

Metastatic lung cancer classically portends a poor prognosis. The management of metastatic lung cancer has dramatically changed with the emergence of immune checkpoint inhibitors, targeted therapy and due to a better understanding of the oligometastatic process. In metastatic lung cancers, radiation therapy which was only used with palliative intent for decades, represents today a promising way to treat primary and oligometastatic sites with a curative intent. Herein we present through a literature review the role of radiotherapy in the management of synchronous metastatic lung cancers.

Randomized phase III trial of metabolic imaging-guided dose escalation of radio-chemotherapy in patients with newly diagnosed glioblastoma (SPECTRO GLIO trial)

BACKGROUND

Glioblastoma (GBM) systematically recurs after a standard 60 Gy radio-chemotherapy regimen. Since magnetic resonance spectroscopic imaging (MRSI) has been shown to predict the site of relapse, we analyzed the effect of MRSI-guided dose escalation on overall survival (OS) of patients with newly diagnosed GBM.

METHODS

In this multicentric prospective phase III trial, patients who had undergone biopsy or surgery for a GBM were randomly assigned to a standard dose (SD) of 60 Gy or a high dose (HD) of 60 Gy with an additional simultaneous integrated boost totaling 72 Gy to MRSI metabolic abnormalities, the tumor bed and residual contrast enhancements. Temozolomide was administered concomitantly and maintained for 6 months thereafter.

RESULTS

One hundred and eighty patients were included in the study between March 2011 and March 2018. After a median follow-up of 43.9 months (95% CI [42.5; 45.5]), median OS was 22.6 months (95% CI [18.9; 25.4]) versus 22.2 months (95% CI [18.3; 27.8]) for HD, and median progression-free survival was 8.6 (95% CI [6.8; 10.8]) versus 7.8 months (95% CI [6.3; 8.6]), in SD versus HD, respectively. No increase in toxicity rate was observed in the study arm. The pseudoprogression rate was similar across the SD (14.4%) and HD (16.7%) groups. For O(6)-methylguanine-DNA methyltransferase (MGMT) methylated patients, the median OS was 38 months (95% CI [23.2; NR]) for HD patients versus 28.5 months (95% CI [21.1; 35.7]) for SD patients.

CONCLUSION

The additional MRSI-guided irradiation dose totaling 72 Gy was well tolerated but did not improve OS in newly diagnosed GBM.

TRIAL REGISTRATION

NCT01507506; registration date: December 20, 2011. https://clinicaltrials.gov/ct2/show/NCT01507506?cond=NCT01507506&rank=1.

Prospective results for 5-year survival and toxicity of moderately hypofractionated radiotherapy with simultaneous integrated boost (SIB) in (very) high-risk prostate cancer

Purpose

High-risk (HR) prostate cancer patients usually receive high-dose radiotherapy (RT) using a two-phase sequential technique, but data on a simultaneous integrated boost (SIB) technique are lacking. We prospectively evaluated the long-term results of urinary (GU) and digestive (GI) toxicity and survival data for high-dose RT using a SIB technique in HR and very high-risk (VHR) prostate cancer.

Methods

Patients were treated using an SIB technique in 34 fractions, at a dose of 54.4 Gy to the pelvis and seminal vesicles and 74.8 Gy to the prostate, combined with 36 months of androgen-depriving therapy in a prospective multicenter study. Acute and late GU and GI toxicity data were collected. Overall survival (OS), biochemical-relapse-free survival (bRFS), loco-regional-relapse-free survival (LRRFS), metastasis-free-survival (MFS) and disease-free-survival (DFS) were assessed.

Results

We recruited 114 patients. After a median follow-up of 62 months, very few patients experienced acute (M0-M3) (G3-4 GU = 3.7 %; G3-4 GI = 0.9 %) or late (M6-M60) severe toxicity (G3-4 GU = 5.6 %; G3-4 GI = 2.8 %). The occurrence of acute G2 + GU or GI toxicity was significantly related to the consequential late G2 + toxicity (p < 0.01 for both GU and GI). Medians of OS, bRFS, LRRFS, MFS and DFS were not reached. At 60 months, OS, bRFS, LRRFS, MFS and DFS were 88.2 % [82.1; 94.7], 86.0 % [79.4 %;93.2 %], 95.8 % [91.8 %;99.9 %], 87.2 % [80.9 %;94.0 %] and 84.1 % [77.2 %;91.6 %] respectively.

Conclusion

SIB RT at a dose of 54.4 Gy to the pelvis and 74.8 Gy to the prostate is feasible, leading to satisfying tumor control and reasonable toxicity in HR and VHR prostate cancer.

[Stereotactic radiotherapy for operable stage I non-small cell lung cancer]

Standard treatment stage of non-small cell lung cancer is currently surgery. For inoperable patients, stereotactic body radiotherapy is the reference treatment. This non-invasive technique has developed considerably and its excellent results in terms of carcinological control and tolerance raise the question of its indication for operable patients, especially for old patients and/or with comorbidities. This article reviews the available data in the literature of the place of stereotactic body radiotherapy for medically operable patients with stage I non-small cell lung cancer.

[Impact of immunotherapy on the therapeutic strategy for the management of stage I non-small cell lung cancer: The radiation oncologist's point of view]

Surgery is the standard treatment for operable patients with stage I non-small cell lung cancer (NSCLC) (T1-T2aN0M0). Stereotactic body radiotherapy (SBRT) is the treatment of choice for non-operable patients, and its positioning for operable patients remains to be clarified. The pattern of recurrence after management of stage I NSCLC is dominated by the risk of distant recurrence, this constituting the rationale for the adjunction of systemic treatment, and especially check point inhibitor (CPI), in combination with surgery or SBRT for patients with high risk features. While the benefit of postoperative CPI on the micro-metastatic disease is logically considered within the framework of a simply additive effect of both therapeutic modalities, it is reasonable to consider a synergistic effect of both CPI and SBRT. Given the role of tumor draining nodes in the development of an anti-tumor immune response, a "tumor-draining node sparing" strategy enabled by SBRT could therefore be of major interest in combination with CPI. Pending confirmation of the role of CPI in combination with RTS for the management of stage I NSCLC, we thus discuss in this review the theoretical advantages that this therapeutic strategy could have compared to a surgical strategy.

Stereotactic body radiotherapy for extra-cranial oligoprogressive or oligorecurrent small-cell lung cancer

Introduction

The role of local ablative treatments, including stereotactic body radiotherapy (SBRT), is an area of active research in oligometastatic patients. Small cell lung cancer (SCLC) has a poor prognosis, with common diffuse metastatic evolution. We evaluated the outcomes after SBRT in uncommon oligoprogressive/oligorecurrent SCLC presentation.

Methods

Data of SCLC patients who received SBRT for oligoprogressive/oligorecurrent metastatic disease at four centers were retrospectively analyzed. Patients with synchronous oligometastatic disease, SBRT for primary lung tumor and brain radiosurgery were not included. Relapse and survival rates were defined as the time between the date of SBRT and the first event.

Results

Twenty patients (60% with initially limited-disease [LD]) presenting 24 lesions were identified. Oligoprogression and oligorecurrence were observed in 6/20 (30%) and 14/20 (70%) patients, respectively. SBRT was delivered to one (n = 16) to two (n = 4) lesions (median size, 26 mm), mainly to lung [n = 17/24] metastases. At a median follow-up of 2.9 years, no local relapse was observed and 15/20 patients experienced a distant relapse (DR). The median DR and OS were 4.5 months (95 %CI: 2.9-13.7 months) and 17.2 months (95 %CI: 7.5-65.2 months), respectively. The 3-year distant control and OS rates were 25% (95 %CI: 6-44%) and 37% (95 %CI: 15-59%), respectively. Initial LD (vs extensive-disease) was the only prognosis factor associated with a lower risk of post-SBRT DR (HR: 0.3; 95% CI: 0-0.88; p = 0.03). There was no severe observed SBRT-related toxicities.

Conclusion

Prognosis was poor, with DR occurring in most patients. However, local control was excellent and long term response after SBRT may rarely occur in patients with oligoprogressive/oligorecurrent SCLC. Local ablative treatments should be discussed in a multidisciplinary setting on well-selected cases.

Impact of radiation on host immune system in patients treated with chemoradiotherapy and durvalumab consolidation for unresectable locally advanced non-small cell lung cancer

Background

The optimal modalities of radiotherapy when combining concurrent chemoradiation (CCRT) and immunotherapy (IO) for locally advanced non-small cell lung cancer (LA-NSCLC) remain to be determined. The aim of this study was to investigate the impact of radiation on different immune structures and immune cells in patients treated with CCRT followed by durvalumab.

Material and methods

Clinicopathologic data, pre- and post-treatment blood counts, and dosimetric data were collected in patients treated with CCRT and durvalumab consolidation for LA-NSCLC. Patients were divided into two groups according to the inclusion (NILN-R+) or not (NILN-R-) of at least one non-involved tumor-draining lymph node (NITDLN) in the clinical target volume (CTV). Progression-free survival (PFS) and overall survival (OS) were estimated by the Kaplan-Meier method.

Results

Fifty patients were included with a median follow-up of 23.2 months (95% CI 18.3-35.2). Two-year PFS and 2-year OS were 52.2% (95% CI 35.8-66.3) and 66.2% (95% CI 46.5-80.1), respectively. In univariable analysis, NILN-R+ (hazard ratio (HR) 2.60, p = 0.028), estimated dose of radiation to immune cells (EDRIC) >6.3 Gy (HR 3.19, p = 0.049), and lymphopenia ≤ 500/mm³ at IO initiation (HR 2.69, p = 0.021) were correlated with poorer PFS; lymphopenia ≤ 500/mm³ was also associated with poorer OS (HR 3.46, p = 0.024). In multivariable analysis, NILN-R+ was the strongest factor associated with PFS (HR 3.15, p = 0.017).

Conclusion

The inclusion of at least one NITDLN station within the CTV was an independent factor for poorer PFS in the context of CCRT and durvalumab for LA-NSCLC. The optimal sparing of immune structures might help in achieving better synergy between radiotherapy and immunotherapy in this indication.

Outcomes following brachytherapy boost for intermediate- and high-risk prostate cancer: A retrospective bicenter study by the SFRO brachytherapy group

INTRODUCTION

Radiotherapy dose escalation improves biochemical control in intermediate- or high-risk prostate cancer. Brachytherapy boost was shown to further improve biochemical control compared to radiotherapy alone in three randomized trials. The SFRO brachytherapy group sought to evaluate the efficacy and toxicity of BT-boost for intermediate and high-risk prostate cancer in real life, and to determine prognostic factors for efficacy and toxicity.

MATERIAL AND METHOD

A retrospective study was conducted, including all patients with intermediate- or high-risk prostate cancer treated with a combination of external beam radiotherapy (EBRT) and high dose-rate brachytherapy boost (HDR-BB), from 2006 until December 2019 at two centers. Patient characteristics, initial disease, treatment and follow-up were collected.

RESULTS

709 patients from two centers were analyzed given a short follow-up in the other centers. Out of those, 277 were intermediate risk (170 favorable and 107 unfavorable) and 432 were high risk. The median EBRT and HDR-BB doses were 46 Gy (35-50) and 14 Gy (10-20). After a median follow-up of 62 months, biochemical control at 5 years was 87.5 % for the overall population, 91 % and 85 % for intermediate- and high-risk cancers, respectively. At 5 years, biochemical and clinical relapse-free survival, metastasis-free survival and local control rates were 83 %, 90 % and 97 % respectively. 5-years overall survival was 94 %. Late grade 2 or higher GU or GI toxicity was found in 36 patients (5 %) and 9 patients (1.3 %).

CONCLUSION

This bicenter analysis shows the efficacy and tolerability of HDR-BB as a complement to external radiotherapy. Further improvements such as combination with new hormonal agents or new brachytherapy-radiotherapy fractionation regimens are warranted to improve further the outcomes and therapeutic ratio.

Consolidative Radiotherapy for Metastatic Urothelial Bladder Cancer Patients with No Progression and with No More than Five Residual Metastatic Lesions Following First-Line Systemic Therapy: A Retrospective Analysis

Local consolidative radiotherapy in the treatment of metastatic malignancies has shown promising results in several types of tumors. The objective of this study was to assess consolidative radiotherapy to the bladder and to residual metastases in metastatic urothelial bladder cancer with no progression following first-line systemic therapy.

MATERIALS/METHODS

Patients who received first-line therapy for the treatment of metastatic urothelial bladder cancer (mUBC) and who were progression-free following treatment with no more than five residual metastases were retrospectively identified through the database of four Comprehensive Cancer Centers, between January 2005 and December 2018. Among them, patients who received subsequent definitive radiotherapy (of EQD2Gy > 45Gy) to the bladder and residual metastases were included in the consolidative group (irradiated (IR) group), and the other patients were included in the observation group (NIR group). Progression-free survival (PFS) and overall survival (OS) were determined from the start of the first-line chemotherapy using the Kaplan-Meier method. To prevent immortal time bias, a Cox model with time-dependent covariates and 6-month landmark analyses were performed to examine OS and PFS.

RESULTS

A total of 91 patients with at least stable disease following first-line therapy and with no more than five residual metastases were analyzed: 51 in the IR group and 40 in the NIR group. Metachronous metastatic disease was more frequent in the NIR group (19% vs. 5%, p = 0.02); the median number of metastases in the IR group vs. in the NIR group was 2 (1-9) vs. 3 (1-5) (p = 0.04) at metastatic presentation, and 1 (0-5) vs. 2 (0-5) (p = 0.18) after completion of chemotherapy (residual lesions), respectively. Two grade 3 toxicities (3.9%) and no grade 4 toxicity were reported in the IR group related to radiotherapy. With a median follow up of 85.9 months (95% IC (36.7; 101.6)), median OS and PFS were 21.7 months (95% IC (17.1; 29.7)) and 11.1 months (95% IC (9.9; 14.1)) for the whole cohort, respectively. In multivariable analysis, consolidative radiotherapy conferred a benefit in both PFS (HR = 0.49, p = 0.007) and OS (HR = 0.47, p = 0.015) in the whole population; in the landmark analysis at 6 months, radiotherapy was associated with improved OS (HR = 0.48, p = 0.026), with a trend for PFS (HR = 0.57, p = 0.082).

CONCLUSION

Consolidative radiotherapy for mUBC patients who have not progressed after first-line therapy and with limited residual disease seems to confer both OS and PFS benefits. The role of consolidative radiotherapy in the context of avelumab maintenance should be addressed prospectively.

Recommendations for stereotactic body radiation therapy for spine and non-spine bone metastases. A GETUG (French society of urological radiation oncolgists) consensus using a national two-round modified Delphi survey

Background and purpose

The relevance of metastasis-directed stereotactic body radiation therapy (SBRT) remains to be demonstrated through phase III trials. Multiple SBRT procedures have been published potentially resulting in a disparity of practices. Therefore, the french society of urological radiation oncolgists (GETUG) recognized the need for joint expert consensus guidelines for metastasis-directed SBRT in order to standardize practice in trials carried out by the group.

Materials and methods

After a comprehensive literature review, 97 recommendation statements were created regarding planning and delivery of spine bone (SBM) and non-spine bone metastases (NSBM) SBRT. These statements were then submitted to a national online two-round modified Delphi survey among main GETUG investigators. Consensus was achieved if a statement received ≥ 75 % agreements, a trend to consensus being defined as 65-74 % agreements. Any statement without consensus at round one was re-submitted in round two.

Results

Twenty-one out of 29 (72.4%) surveyed experts responded to both rounds. Seventy-five statements achieved consensus at round one leaving 22 statements needing a revote of which 16 achieved consensus and 5 a trend to consensus. The final rate of consensus was 91/97 (93.8%). Statements with no consensus concerned patient selection (3/19), dose and fractionation (1/11), prescription and dose objectives (1/9) and organs at risk delineation (1/15). The voting resulted in the writing of step-by-step consensus guidelines.

Conclusion

Consensus guidelines for SBM and NSBM SBRT were agreed upon using a validated modified Delphi approach. These guidelines will be used as per-protocole recommendations in ongoing and further GETUG clinical trials.

[Bladder-sparing trimodal therapy for muscle invasive bladder cancer]

Organ-sparing strategies in the management of local or locally advanced cancers meet a dual objective: tumor control and preservation of the function of the involved organ. Given the morbidity and mortality of cystectomy and its impact on quality of life and bladder function, bladder-sparing strategies have emerged for the management of urothelial muscle invasive bladder cancer, mostly through trimodal treatment, which consists in maximal trans-urethral resection of bladder tumor, followed by chemo-radiotherapy. This review presents the modalities of trimodal treatment, before exposing the advantages and limitations of this strategy compared to cystectomy among operable patients. Despite the absence of comparative data from randomized trials, the two approaches seem to provide similar oncological results among appropriately selected patients. In modern series, the rate of salvage cystectomy is approximately 15% at 5 years; this delayed cystectomy does not seem to be associated with greater morbidity and mortality as compared to upfront cystectomy. Emphasis is placed in the review on quality of life data of these two approaches. In order to optimize the selection of patients eligible to trimodal therapy, the classical predictive factors of response to radio(chemo)therapy are critically analyzed, with the perspective of innovative molecular biomarkers. Finally, a close multidisciplinary collaboration is needed for the choice and the execution of the therapeutic strategy, and the patient should be fully involved in the decision-making process.

Impact of radiotherapy on survival in resected or unresectable anaplastic thyroid carcinomas, a Rare Cancer Network study

PURPOSE

Anaplastic thyroid carcinomas (ATC) are a heterogenous group of tumors of overall dismal prognosis. We designed models to identify relevant prognostic factors of survival of irradiated ATC patients including radiotherapy modalities (field size, dose).

MATERIAL AND METHODS

Between 2000 and 2017, 166 ATC patients' treatments were divided into surgery and postoperative radiotherapy (poRT) or definitive radiotherapy (RT). Multiple imputation approach was used for missing data. Prognostic factors were identified using Lasso-penalized Cox modelling and predicted risk scores were built.

RESULTS

Patients undergoing RT (n=70) had more adverse patient and disease characteristics than those undergoing poRT (n=96). Corresponding median survival rates were 5.4 and 12.1 months, respectively. PoRT patients undergoing poRT more likely received extended-field radiotherapy with prophylactic nodal irradiation, but rather received platinum- vs. adriamycin-based chemoradiotherapy. Radiotherapy was conventionally fractionated, delivered >60Gy in 51.9% and 61.7% and used extended fields in 88.5% and 71.2% of patients with poRT or RT. Radiotherapy interruption rates for toxicity were similar in the two groups. The best poRT-group model identified age>45yo, PS≥1, pathologic tumor stage≥pT4b,>N1 and R2 resection as poor prognostic factors. The best RT-group model (C-index of 0.72) identified PS≥3,>N1 and extended-field radiotherapy with prophylactic nodal irradiation (as opposed to tumour-bed irradiation only) as poor prognostic factors.

CONCLUSION

In patients undergoing poRT, radiotherapy parameters had little influence over their survival irrespective of patient, disease characteristics, and quality of resection. In patients undergoing RT, extended-field radiotherapy improved survival in addition to PS and nodal stage.

Multimodality planning of stereotactic radio-ablation for ventricular tachycardia. Results from the international MUSIC consortium

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Research Council

Background

Optimal SBRT planning methods for VT ablation are yet to be defined.

Purpose

To evaluate a multimodal approach for SBRT planning.

Methods

30 pts (age 70±10, 90% men, LVEF 26±9%, 67% ICM, 47% NICM or mixed, 1.7±1.2 prior catheter ablations) with drug-refractory VT underwent imaging prior to SBRT. The inHEART technology was used to create image-based 3D models of substrate, cardiac anatomy, and organs at risk (coronaries, phrenic nerve, GI tract, AV node). In MUSIC software (IHU Liryc-Inria), 3D models were fused with prior EP maps, and SBRT targets were interactively drawn in 3D by the referring EP cardiologist. Transmural target volumes and organs at risk were fused with a 4D planning CT and used to plan SBRT in Eclipse (Varian).

Results

SBRT was delivered on median PTVs of 96[63-149] mL (total dose 25 Gy) with either Truebeam or Edge systems (Varian). Over a median FU of 4[2-8] months, death occurred in 11(37%) pts, due to arrhythmia recurrence in 4(13%). FU at 6 months was available in 14 pts. In these, the median numbers of VT episodes and ICD shocks over the 6 months preceding SBRT were 20[9-27] and 8[5-15], respectively. In the 6 months following SBRT, these decreased to 0[0-30] and 0[0-0], respectively (P&lt;0.001 for both). 8/14(57%) pts were free from any VT recurrence, and 11/14(79%) were free from any ICD shock. In the total cohort, complications attributed to SBRT were observed in 2/30 (7%), none of which were fatal (heart failure and pneumonitis, both managed with steroids).

Conclusion

In patients with severe drug- and catheter ablation-refractory VT, SBRT planning based on 3D image-based models fused with prior EP maps is feasible, and associated with favorable efficacy and safety profiles.

Cost and Toxicity Comparisons of Two IMRT Techniques for Prostate Cancer: A Micro-Costing Study and Weighted Propensity Score Analysis Based on a Prospective Study

BACKGROUND

Intensity modulated radiation therapy (IMRT) combined with androgen deprivation therapy (ADT) has become the standard treatment for patients with high-risk prostate cancer. Two techniques of rotational IMRT are commonly used in this indication: Volumetric Modulated Arc Therapy (VMAT) and helical tomotherapy (HT). To the best of our knowledge, no study has compared their related costs and clinical effectiveness and/or toxicity in prostate cancer. We aimed to assess differences in costs and toxicity between VMAT and HT in patients with high-risk prostate cancer with pelvic irradiation.

MATERIAL AND METHODS

We used data from the "RCMI pelvis" prospective multicenter study (NCT01325961) including 155 patients. We used a micro-costing methodology to identify cost differences between VMAT and HT. To assess the effects of the two techniques on total actual costs per patient and on toxicity we used stabilized inverse probability of treatment weighting.

RESULTS

The mean total cost for HT, €2019 3,069 (95% CI, 2,885-3,285) was significantly higher than the mean cost for VMAT €2019 2,544 (95% CI, 2,443-2,651) (p <.0001). The mean ± SD labor and accelerator cost for HT was €2880 (± 583) and €1978 (± 475) for VMAT, with 81 and 76% for accelerator, respectively. Acute GI and GU toxicity were more frequent in VMAT than in HT (p = .021 and p = .042, respectively). Late toxicity no longer differed between the two groups up to 24 months after completion of treatment.

CONCLUSION

Use of VMAT was associated with lower costs for IMRT planning and treatment than HT. Similar stabilized long-term toxicity was reported in both groups after higher acute GI and GU toxicity in VMAT. The estimates provided can benefit future modeling work like cost-effectiveness analysis.

Radiotherapy for primary lung cancer

Herein are presented the recommendations from the Société française de radiothérapie oncologique regarding indications and modalities of lung cancer radiotherapy. The recommendations for delineation of the target volumes and organs at risk are detailed.

Dose-Response Effect and Dose-Toxicity in Stereotactic Radiotherapy for Brain Metastases: A Review

Simple Summary

Brain metastases are one of the most frequent complications for cancer patients. Stereotactic radiosurgery is considered a cornerstone treatment for patients with limited brain metastases and the ideal dose and fractionation schedule still remain unknown. The aim of this literature review is to discuss the dose-effect relation in brain metastases treated by stereotactic radiosurgery, accounting for fractionation and technical considerations.

Abstract

For more than two decades, stereotactic radiosurgery has been considered a cornerstone treatment for patients with limited brain metastases. Historically, radiosurgery in a single fraction has been the standard of care but recent technical advances have also enabled the delivery of hypofractionated stereotactic radiotherapy for dedicated situations. Only few studies have investigated the efficacy and toxicity profile of different hypofractionated schedules but, to date, the ideal dose and fractionation schedule still remains unknown. Moreover, the linear-quadratic model is being debated regarding high dose per fraction. Recent studies shown the radiation schedule is a critical factor in the immunomodulatory responses. The aim of this literature review was to discuss the dose–effect relation in brain metastases treated by stereotactic radiosurgery accounting for fractionation and technical considerations. Efficacy and toxicity data were analyzed in the light of recent published data. Only retrospective and heterogeneous data were available. We attempted to present the relevant data with caution. A BED10 of 40 to 50 Gy seems associated with a 12-month local control rate >70%. A BED10 of 50 to 60 Gy seems to achieve a 12-month local control rate at least of 80% at 12 months. In the brain metastases radiosurgery series, for single-fraction schedule, a V12 Gy < 5 to 10 cc was associated to 7.1–22.5% radionecrosis rate. For three-fractions schedule, V18 Gy < 26–30 cc, V21 Gy < 21 cc and V23 Gy < 5–7 cc were associated with about 0–14% radionecrosis rate. For five-fractions schedule, V30 Gy < 10–30 cc, V 28.8 Gy < 3–7 cc and V25 Gy < 16 cc were associated with about 2–14% symptomatic radionecrosis rate. There are still no prospective trials comparing radiosurgery to fractionated stereotactic irradiation.

Recommendations for planning and delivery of radical radiotherapy for localized urothelial carcinoma of the bladder

PURPOSE

Curative radio-chemotherapy is recognized as a standard treatment option for muscle-invasive bladder cancer (MIBC). Nevertheless, the technical aspects for MIBC radiotherapy are heterogeneous with a lack of practical recommendations.

METHODS AND MATERIALS

In 2018, a workshop identified the need for two cooperative groups to develop consistent, evidence-based guidelines for irradiation technique in the delivery of curative radiotherapy. Two radiation oncologists performed a review of the literature addressing several topics relative to radical bladder radiotherapy: planning computed tomography acquisition, target volume delineation, radiation schedules (total dose and fractionation) and dose delivery (including radiotherapy techniques, image-guided radiotherapy (IGRT) and adaptive treatment modalities). Searches for original and review articles in the PubMed and Google Scholar databases were conducted from January 1990 until March 2020. During a meeting conducted in October 2020, results on 32 topics were presented and discussed with a working group involving 15 radiation oncologists, 3 urologists and one medical oncologist. We applied the American Urological Association guideline development's method to define a consensus strategy.

RESULTS

A consensus was obtained for all 34 except 4 items. The group did not obtain an agreement on CT enhancement added value for planning, PTV margins definition for empty bladder and full bladder protocols, and for pelvic lymph-nodes irradiation. High quality evidence was shown in 6 items; 8 items were considered as low quality of evidence.

CONCLUSION

The current recommendations propose a homogenized modality of treatment both for routine clinical practice and for future clinical trials, following the best evidence to date, analyzed with a robust methodology. The XXX group formulates practical guidelines for the implementation of innovative techniques such as adaptive radiotherapy.

Consolidative radiotherapy for metastatic urothelial bladder cancer patients without progression and with no more than three residual metastatic lesions following first line systemic therapy: A prospective randomized comparative phase II trial (BLAD RAD01/GETUG-AFU V07)

TPS4588

Background: Consolidative local treatment of the primary tumor in the treatment of metastatic malignancies has shown promising results in several types of tumors, mostly relying on the seed-and-soil theory. Furthermore, the local treatment of the residual metastases following systemic treatment is a promising approach, in part due to the high incidence of progression at prior sites of disease in patients who had initially responded to chemotherapy. To date, no prospective data exists on such consolidative approach in metastatic urothelial bladder cancer (mUBC). The phase II trial BLAD-RAD01 GETUG-AFU V07 was designed to investigate the role of local consolidative radiotherapy in patients with limited mUBC and without progression following the initial phase of first-line systemic therapy. Methods: This is a phase II, multicenter, randomized open-label and comparative study. Patients with mUBC (excluding brain and liver metastases), without progression following standard first-line systemic therapy according to RECIST v1.1, and with no more than 3 residual metastatic lesions on 18FDG-PET scanner and/or contrast-enhanced CT-scanner are eligible for the study. After the completion of systemic treatment, an estimated 130 patients will be randomized in a 1:1 ratio between consolidative local treatment (pelvic radiotherapy +/- previous transurethal resection of bladder tumor, associated with stereotactic body radiotherapy (SBRT) to the residual metastases) plus standard of care (arm B) and standard of care only (arm A). Stratification is performed based upon: the center, the ECOG performance status, the administration of immunotherapy or not, the number of residual metastatic lesions and the imaging modality for assessment of the number of residual lesions. To date, standard of care for this population is maintenance treatment with avelumab. Radiotherapy regimens consist in conventionally fractionated (64Gy in 32 fractions) or hypofractionated (55Gy in 20 fractions) irradiation of the bladder, optional pelvic nodes irradiation, and 3 to 5 fractions of 6 to 18 Gy in SBRT for metastases, depending on the location. The main objective is to detect an increase in 20-month overall survival rate following chemotherapy from 50% (based upon the JAVELIN 100 trial) to 66%; this corresponds to a hazard ratio of 0.6. A total of 83 events are necessary for 85% power to detect this difference if it is true using a one-sided logrank test at the 10% of significance. Target difference, type I and II error rates are relaxed and compatibles with recommendations for comparative phase II trials. Key secondary endpoints are progression free survival, safety and quality of life. To date, one patient has been enrolled and eight centers are open for accrual. Clinical trial information: NCT04428554.

Radiotherapy in the Era of Immunotherapy With a Focus on Non-Small-Cell Lung Cancer: Time to Revisit Ancient Dogmas?

Radiation-induced immune effects have been extensively deciphered over the last few years, leading to the concept of the dual immune effect of radiotherapy with both immunostimulatory and immunosuppressive effects. This explains why radiotherapy alone is not able to drive a strong anti-tumor immune response in most cases, hence underlining the rationale for combining both radiotherapy and immunotherapy. This association has generated considerable interest and hundreds of trials are currently ongoing to assess such an association in oncology. However, while some trials have provided unprecedented results or shown much promise, many hopes have been dashed. Questions remain, therefore, as to how to optimize the combination of these treatment modalities. This narrative review aims at revisiting the old, well-established concepts of radiotherapy relating to dose, fractionation, target volumes and organs at risk in the era of immunotherapy. We then propose potential innovative approaches to be further assessed when considering a radio-immunotherapy association, especially in the field of non-small-cell lung cancer (NSCLC). We finally propose a framework to optimize the association, with pragmatic approaches depending on the stage of the disease.

Role of consolidative radiotherapy for metastatic urothelial bladder cancer patients without progression and with no more than five residual metastatic lesions following first line systemic therapy: A retrospective analysis

454

Background: Consolidative local treatment of the primary tumor and metastases in the treatment of metastatic malignancies has shown promising results in several types of primary tumors. The aim of this study is to assess consolidative radiotherapy to the bladder and to residual metastases among metastatic urothelial bladder cancer with no progression following first line systemic therapy, hypothesizing an increase in overall survival and in progression free survival. Methods: Between January 2005 and December 2018, patients who received standard first-line chemotherapy for the treatment of metastatic urothelial bladder cancer (mUBC) were retrospectively identified through the database of four Comprehensive Cancer Centers in France. Among them, patients with no disease progression following chemotherapy and with no more than 5 residual metastases were analyzed: patients who received subsequent radiotherapy (of EQD2Gy > 50Gy) to the bladder and residual metastases were included in the consolidative group (RT group), and the other patients were included in the observation group (OBS group). PFS and OS were determined from the start of the first-line chemotherapy using the Kaplan-Meier method. To account for the delay from chemotherapy initiation to consolidative radiotherapy, a Cox model with time-dependant covariates, and a 6-month landmark analyses were performed to examine OS and PFS. Results: A total of 91 patients with at least stable disease following chemotherapy and with no more than 5 residual metastases were analyzed: 51 in the RT group and 40 in the OBS group. Metachronous metastatic disease (following definitive treatment of localized UBC) was more frequent in the OBS group (19% vs 5%, p = 0.02); the median number of metastases in the RT group vs in the OBS group was: 2 (1-9) vs 3 (1-5) (p = 0.04) at metastatic presentation, and 1 (0-5) vs 2 (0-5) (p = 0.18) after completion of chemotherapy (residual lesions), respectively. Two grade 3 toxicities (3.9%) and no grade 4 toxicity were reported in the RT group. With a median follow up of 85.9 months (95% IC [36.7; 101.6]), median OS and PFS were 21.7 months (95% IC [17.1; 29.7]) and 11.1 months (95% IC [9.9; 14.1]) for the whole cohort, respectively. In multivariable analysis: consolidative RT in comparison with observation was associated with improved OS in both the standard analysis (HR = 0.47, p = 0.015) and in the 6-month landmark analysis (HR = 0.48, p = 0.026); and with improved PFS only in the standard analysis (HR = 0.49, p = 0.007). Conclusions: Consolidative radiotherapy for mUBC patients who have not progressed after chemotherapy and with limited residual disease seems to confer both OS and PFS advantage. Prospective data in that field with addition of avelumab are needed.

RADIORYTHMIC: Phase III, Opened, Randomized Study of Postoperative Radiotherapy Versus Surveillance in Stage IIb/III of Masaoka Koga Thymoma after Complete Surgical Resection

INTRODUCTION

Thymomas are rare intrathoracic malignancies that may be aggressive and difficult to treat. Knowledge and level of evidence for treatment strategies are mainly based on retrospective studies or expert opinion. Currently there is no strong evidence that postoperative radiotherapy after complete resection of localized thymoma is associated with survival benefit in patients. RADIORYTHMIC is a phase III, randomized trial aiming at comparing postoperative radiotherapy versus surveillance after complete resection of Masaoka-Koga stage IIb/III thymoma. Systematic central pathologic review will be performed before patient enrollment as per the RYTHMIC network pathway.

PATIENTS AND METHODS

Three hundred fourteen patients will be included; randomization 1:1 will attribute either postoperative radiotherapy (50-54 Gy to the mediastinum using intensity-modulated radiation therapy or proton beam therapy) or surveillance. Stratification criteria include histologic grading (thymoma type A, AB, B1 vs B2, B3), stage, and delivery of preoperative chemotherapy. Patient recruitment will be mainly made through the French RYTHMIC network of 15 expert centers participating in a nationwide multidisciplinary tumor board. Follow-up will last 7 years. The primary endpoint is recurrence-free survival. Secondary objectives include overall survival, assessment of acute and late toxicities, and analysis of prognostic and predictive biomarkers.

RESULTS

The first patient will be enrolled in January 2021, with results expected in 2028.

Focus on stereotactic radiotherapy: A new way to treat severe ventricular arrhythmias?

Ventricular tachycardia has a significant recurrence rate after ablation for several reasons, including inaccessible substrate. A non-invasive technique to ablate any defined areas of myocardium involved in arrhythmogenesis would be a potentially important therapeutic improvement if shown to be safe and effective. Early feasibility studies of single-fraction stereotactic body radiotherapy have demonstrated encouraging results, but rigorous evaluation and follow-up are required. In this document, the basic concepts of stereotactic body radiotherapy are summarized, before focusing on stereotactic arrhythmia radioablation. We describe the effect of radioablation on cardiac tissue and its interaction with intracardiac devices, depending on the dose. The different clinical studies on ventricular tachycardia radioablation are analysed, with a focus on target identification, which is the key feature of this approach. Our document ends with the indications and requirements for practicing this type of procedure in 2020. Finally, because of the limited number of patients treated so far, we encourage multicentre registries with long-term follow-up.

Brachytherapy boost (BT-boost) or stereotactic body radiation therapy boost (SBRT-boost) for high-risk prostate cancer (HR-PCa)

Systematic review for the treatment of high-risk prostate cancer (HR-PCa, D'Amico classification risk system) with external body radiation therapy (EBRT)+brachytherapy-boost (BT-boost) or with EBRT+stereotactic body RT-boost (SBRT-boost). In March 2020, 391 English citations on PubMed matched with search terms "high risk prostate cancer boost". Respectively 9 and 48 prospective and retrospective studies were on BT-boost and 7 retrospective studies were on SBRT-boost. Two SBRT-boost trials were prospective. Only one study (ASCENDE-RT) directly compared the gold standard treatment [dose-escalation (DE)-EBRT+androgen deprivation treatment (ADT)] versus EBRT+ADT+BT-boost. Biochemical control rates at 9 years were 83% in the experimental arm versus 63% in the standard arm. Cumulative incidence of late grade 3 urinary toxicity in the experimental arm and in the standard arm was respectively 18% and 5%. Two recent studies with HR-PCa (National Cancer Database) demonstrated better overall survival with BT-boost (low dose rate LDR or high dose rate HDR) compared with DE-EBRT. These recent findings demonstrate the superiority of EBRT+BT-boost+ADT versus DE-EBRT+ADT for HR-PCa. It seems that EBRT+BT-boost+ADT could now be considered as a gold standard treatment for HR-PCa. HDR or LDR are options. SBRT-boost represents an attractive alternative, but the absence of randomised trials does not allow us to conclude for HR-PCa. Prospective randomised international phase III trials or meta-analyses could improve the level of evidence of SBRT-boost for HR-PCa.

[A review of adaptive radiotherapy for bladder cancer]

PURPOSE

Radiation therapy (RT) for muscle invasive bladder cancer (MIBC) is challenging, with observed variations in bladder shape and size resulting in inappropriate coverage of the target volumes (CTV). Large margins were historically applied around the CTV, increasing the dose delivered to organs at risk (OAR). With repositioning imaging and visualization of soft tissues during image guided RT, an opportunity to consider these movements and deformations appeared possible with an adaptive RT approach (ART).

MATERIALS AND METHODS

A bibliographic search on the PubMed database has been done in January 2019. Studies focusing on patients with MIBC, treating on ART, with the objectives of feasibility, clinical and/or dosimetric evaluation and comparison with a standard irradiation technique were eligible. The purpose of this review was to define the different ART techniques used in clinical practice, to discuss their advantages compared to conventional RT in terms of target volume's coverage and OAR dose and to describe their feasibility in clinical practice.

RESULTS

A total of 30 studies were selected. The strategies known as "composite offline", "plan of the day" not individualized or individualized, and "re-optimization" have been identified. All the studies have shown a significant benefit of ART in target coverage and dose of OAR, especially the rectum and small bowel. All ART plans produced are not used during RT sessions. Inter-observer variability for the selection of these plans can be observed. The practical implementation within a department required staff education and training, and increases the duration of treatment preparation. The "A-POLO" approach seems to be the most suitable for practice.

CONCLUSION

ART is the technique of choice for bladder cancer RT. The "plan of the day" approach, individualized according to the A-POLO methodology, seems to be the most effective. The emergence of daily re-optimization, especially using MRI-Linac, is promising. The correlation between dosimetric benefits and clinical efficacy and safety results should be demonstrated into future trials.

Laparoscopic closure of the pouch of Douglas by a peritoneal running suture. A minimally invasive and prosthetic-free technique to prevent excessive dose delivery to the small bowel during pelvic irradiation for prostate cancer

•

The radiation tolerance of the small bowel is limited.

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Chronic radiation-induced enteritis affects patients quality of life.

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Ectopic small bowel loops trapped in the pelvis may challenge prostate radiotherapy.

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A laparoscopic prosthetic-free technique to cordon off bowel loops from the pelvis.

Background and purpose

Prostate radiotherapy relies on the delivery of high doses that can be obstructed when a small bowel loop descends in the pelvis. We present a laparoscopic minimally invasive prosthetic-free technique closing the Douglas’ pouch with a peritoneal running suture to cordon off the bowel from the pelvis and hence allow optimal irradiation.

Materials and methods

Prostate cancer patients referred for radiotherapy and whose planning-CT revealed a bowel loop trapped in the pelvis were proposed the procedure, followed by a new planning-CT. This proof-of-concept study reports postoperative follow-up and dosimetric benefits.

Results

The procedure was performed in ten patients (2016–2020) as a same-day surgery for nine. Median operative time was 34 min (range 22–50) and no relevant intraoperative complication occurred. The third patient of the series presented a small bowel hernia through the peritoneal suture at the 15th postoperative day requiring a laparotomic desincarceration without major consequences. Regarding the small bowel, median D1cc (dose to 1 cc) was 65.5 Gy and 55.5 Gy (p = 0.005) before and after procedure. Median V60 (volume receiving ≥60 Gy) was 10.2 cc and 0.0 cc (p = 0.005). In the immediate vicinity of the small bowel (5 mm), median D1cc was 68.3 Gy and 57.7 Gy (p = 0.005). Radiotherapy was safely delivered to all patients.

Conclusion

Laparoscopic closure of the Douglas’ pouch by a peritoneal suture is an efficient technique to cordon off inconvenient ectopic small bowel loops. It prevents excessive bowel irradiation and hence facilitates curative prostate radiotherapy. The technique could be applied to other pelvic malignancies.

Novel Methodology to Investigate the Effect of Radiation Dose to Heart Substructures on Overall Survival

PURPOSE

For patients with lung cancer treated with radiation therapy, a dose to the heart is associated with excess mortality; however, it is often not feasible to spare the whole heart. Our aim is to define cardiac substructures and dose thresholds that optimally reduce early mortality.

METHODS AND MATERIALS

Fourteen cardiac substructures were delineated on 5 template patients with representative anatomies. One thousand one hundred sixty-one patients with non-small cell lung cancer were registered nonrigidly to these 5 template anatomies, and their radiation therapy doses were mapped. Mean and maximum dose to each substructure were extracted, and the means were evaluated as input to prediction models. The cohort was bootstrapped into 2 variable reduction techniques: elastic net least absolute shrinkage and selection operator and the random survival forest model. Each method was optimized to extract variables contributing most to overall survival, and model coefficients were evaluated to select these substructures. The most important variables common to both models were selected and evaluated in multivariable Cox-proportional hazard models. A threshold dose was defined, and Kaplan-Meier survival curves plotted.

RESULTS

Nine hundred seventy-eight patients remained after visual quality assurance of the registration. Ranking the model coefficients across the bootstraps selected the maximum dose to the right atrium, right coronary artery, and ascending aorta as the most important factors associated with survival. The maximum dose to the combined cardiac region showed significance in the multivariable model, a hazard ratio of 1.01/Gy, and P = .03 after accounting for tumor volume (P < .001), N stage (P < .01), and performance status (P = .01). The optimal threshold for the maximum dose, equivalent dose in 2-Gy fractions, was 23 Gy. Kaplan-Meier survival curves showed a significant split (log-rank P = .008).

CONCLUSIONS

The maximum dose to the combined cardiac region encompassing the right atrium, right coronary artery, and ascending aorta was found to have the greatest effect on patient survival. A maximum equivalent dose in 2-Gy fractions of 23 Gy was identified for consideration as a dose limit in future studies.

Brain metastases from germ cell tumor: time to reconsider radiotherapy?

The presence of brain metastases (BMs) from germ cell tumor (GCT) remains a rare situation. BMs predominantly occur among patients with testis primary tumor site, and are almost exclusively associated with non-seminomatous (NS) histologies. Two situations must be distinguished, which differ in terms of clinical presentation, overall prognostic and management. At diagnosis, BMs are almost systematically associated with extra-cerebral metastases and the cornerstone of treatment is chemotherapy, while the role of local treatment remains controversial. In the metachronous setting, BMs more frequently constitute an isolated site of relapse, the outcome is poorer, and the role of local treatment is more consensual. However, all these data widely come from old reports, with outdated radiation techniques. The recent advances in radiation oncology, especially the rising use of stereotactic radiotherapy, could lead to the reconsideration of ancient dogmas regarding the "radiosensitivity" of (NS)GCT and the role of radiotherapy among patients with BMs.

Effect of orbital radiotherapy on the outcome of surgical orbital decompression for thyroid-associated orbitopathy (TAO): a retrospective study in 136 patients

PURPOSE

In patients with moderate to severe thyroid-associated orbitopathy (TAO), orbital radiation therapy (ORT) can prevent disease progression. In the sequelae stage, orbital decompression surgery can be useful in case of functional discomfort. The aim of this study was to evaluate the effect of orbital ORT on the outcomes of decompression surgery.

METHODS

In this retrospective study, we included 136 patients who had had bilateral orbital decompression between 1995 and 2016. Before surgery, 38 patients received Radiation Therapy (RT+) while 98 did not (RT-). All RT+ patients and 20 RT- patients had systemic corticosteroid treatment. In both groups surgical outcome was evaluated by exophthalmos reduction (mm), palpebral fissure (mm), distance between the lid margin and the corneo-scleral limbus (mm), existence of conjunctival hyperemia and diplopia.

RESULTS

In both RT+ and RT- groups, surgery improved the proptosis, significantly greater in RT+(3.66 ± 1.79 mm) than in RT- group (2.85 ± 1.80 mm) (p < 0.019). No significant differences were noted in the palpebral fissure, the distance from the lid margin to the corneo-scleral limbus. After surgery, only one patient (5%) in the RT+ group presented with new-onset diplopia, whereas in the RT- group there were 14 (36%) patients (p < 0.007). After orbital decompression, the number of conjunctival hyperemia decreased by 6 (21%) in the RT+ group versus 21 (60%) in the RT- group (p < 0.006).

CONCLUSION

Orbital radiotherapy during the inflammatory phase enhances the outcomes after orbital decompression in TAO. After surgery we observed a greater improvement in proptosis and in diplopia for RT+ versus RT- patients.

Inter-observer variability in target delineation increases during adaptive treatment of head-and-neck and lung cancer

Introduction: Inter-observer variability (IOV) in target volume delineation is a well-documented source of geometric uncertainty in radiotherapy. Such variability has not yet been explored in the context of adaptive re-delineation based on imaging data acquired during treatment. We compared IOV in the pre- and mid-treatment setting using expert primary gross tumour volume (GTV) and clinical target volume (CTV) delineations in locoregionally advanced head-and-neck squamous cell carcinoma (HNSCC) and (non-)small cell lung cancer [(N)SCLC]. Material and methods: Five and six observers participated in the HNSCC and (N)SCLC arm, respectively, and provided delineations for five cases each. Imaging data consisted of CT studies partly complemented by FDG-PET and was provided in two separate phases for pre- and mid-treatment. Global delineation compatibility was assessed with a volume overlap metric (the Generalised Conformity Index), while local extremes of IOV were identified through the standard deviation of surface distances from observer delineations to a median consensus delineation. Details of delineation procedures, in particular, GTV to CTV expansion and adaptation strategies, were collected through a questionnaire. Results: Volume overlap analysis revealed a worsening of IOV in all but one case per disease site, which failed to reach significance in this small sample (p-value range .063-.125). Changes in agreement were propagated from GTV to CTV delineations, but correlation could not be formally demonstrated. Surface distance based analysis identified longitudinal target extent as a pervasive source of disagreement for HNSCC. High variability in (N)SCLC was often associated with tumours abutting consolidated lung tissue or potentially invading the mediastinum. Adaptation practices were variable between observers with fewer than half stating that they consistently adapted pre-treatment delineations during treatment. Conclusion: IOV in target volume delineation increases during treatment, where a disparity in institutional adaptation practices adds to the conventional causes of IOV. Consensus guidelines are urgently needed.

Gene therapy and cell therapy for the management of radiation damages to healthy tissues: Rationale and early results

Nowadays, ionizing radiations have numerous applications, especially in medicine for diagnosis and therapy. Pharmacological radioprotection aims at increasing detoxification of free radicals. Radiomitigation aims at improving survival and proliferation of damaged cells. Both strategies are essential research area, as non-contained radiation can lead to harmful effects. Some advances allowing the comprehension of normal tissue injury mechanisms, and the discovery of related predictive biomarkers, have led to developing several highly promising radioprotector or radiomitigator drugs. Next to these drugs, a growing interest does exist for biotherapy in this field, including gene therapy and cell therapy through mesenchymal stem cells. In this review article, we provide an overview of the management of radiation damages to healthy tissues via gene or cell therapy in the context of radiotherapy. The early management aims at preventing the occurrence of these damages before exposure or just after exposure. The late management offers promises in the reversion of constituted late damages following irradiation.

10-Year Locoregional Control with Postoperative External Beam Radiotherapy in Patients with Locally Advanced High-Risk Non-Anaplastic Thyroid Carcinoma De Novo or at Relapse, a Propensity Score Analysis

(1) Background: To assess the role of postoperative external beam radiotherapy (pEBRT) on locoregional failure (LRF) for patients with locally advanced high-risk non-anaplastic thyroid carcinoma (naTC) at primary event or relapse. (2) Methods: Between 1995 and 2015, postoperative naTC patients with a theoretical indication for EBRT were included based on criteria that were common to American-British-French current guidelines, i.e., pT3-4, pN+, gross or microscopic residual disease. Inverse probability of treatment weighting (IPTW) after multiple imputation was used to reduce selection biases. (3) Results: Of 254 naTC patients, 216 patients underwent pEBRT (106 de novo, 110 at relapse, median dose 60 Gy) and 38 underwent surgery only. pEBRT patients had more gross residual disease, a major prognostic factor (p = 0.027) but less perineural invasion (p = 0.008) or lymphovascular emboli (p = 0.009). pEBRT patients more frequently underwent radioiodine therapy (p = 0.026). The 10-year cumulative incidence of LRF was 56% (95% CI, 32–74%) in operated patients, and 23% (95% CI, 17–30%) in pEBRT patients. After IPTW method, pEBRT reduced the risk of LRF (hazard ratio 0.30; 95% CI [0.18–0.49], p < 0.001), but had no impact on OS. In the pEBRT group, non-Intensity Modulated RadioTherapy (IMRT) plans and interruption of the radiotherapy were associated with poorer survival, while extended versus limited field strategy and dose were not. (4) Conclusions: In naTC patients who have pT3-4, pN+ disease or R1-2 resection, pEBRT improved LRF. Limited-field IMRT is preferred.

Prostate image-guided transperineal elastic-registration biopsy, a new diagnostic tool to refine the risk-stratification of prostate cancer and improve therapeutic decisions

e16595

Background: To evaluate image-guided Transperineal Elastic-Registration biopsy (TPER-B) in the risk-stratification of low-to-intermediate risk prostate cancer detected by Transrectal-ultrasound biopsy (TRUS-B) when estimates of cancer grade and volume discorded with multiparametric Magnetic Resonance Imaging (MRI). Methods: All patients referred for active surveillance or organ-conservative management were collegially reviewed for consistency between TRUS-B results and MRI. Image-guided TPER-B of the index target (IT) defined as the largest Prostate Imaging-Reporting Data System-v2 ≥3 abnormality were organized for discordant cases. Pathology reported Gleason grade, maximum cancer core length (MCCL) and total CCL (TCCL). Results: Of 237 prostate cancer patients (1-7/2018), 42 required TPER-B for risk-stratification. Eight cores were obtained [Median&IQR: 8 (6-10)] including five (IQR: 4-6) in the IT. TPER-B of the IT yielded longer MCCL [Mean&(95%CI): 5.4(3.9-6.9) vs. 2.5mm(1.9-3.1), p = 0.002] and TCCL [16.7(10.6-22.8) vs. 3.9mm(3.1-4.8), p = 0.0001] than TRUS-B of the gland. On TPER-B cores, longer TCCL [Mean&(95%CI): 28.9mm(19.1-38.7) vs. 12.3mm(4.8-19.7), p = 0.02] were measured in Gleason score-7 than score-6 cancers (no cancers detected on IT TPER-B in 11 patients, all but one score 6 < 4mm on TRUS-B). TPER-B cores of the IT upgraded 16/42(38.1%) patients. 21/42(50.0%) met University College London-definition 1 (Gleason score≥4+3 and/or MCL≥6mm) and 27/42(64.3%) definition 2 (Gleason score≥3+4 and/or MCL≥4mm), which correlate to clinically significant cancers > 0.5mL and > 0.2mL, respectively. Allocation to higher risk groups than anticipated from TRUS-B spurred adaptation of treatment protocols (active surveillance n = 15, prostatectomy n = 11, ionizing radiation n = 13, pending n = 3). Conclusions: Image-guided TPER-B of the index target provided more cancer material for pathology. Subsequent re-evaluation of cancer volume and grade switched a majority of patients towards higher risk groups and treatments with curative intent.

Unilateral or bilateral irradiation in cervical lymph node metastases of unknown primary? A retrospective cohort study

INTRODUCTION

Patients with cervical lymphadenopathy of unknown primary carcinoma (CUP) usually undergo neck dissection and irradiation. There is an ongoing controversy regarding the extent of nodal and mucosal volumes to be irradiated. We assessed outcomes after bilateral or unilateral nodal irradiation.

METHODS

This retrospective multicentre study included patients with CUP and squamous cellular carcinoma who underwent radiotherapy (RT) between 2000 and 2015.

RESULTS

Of 350 patients, 74.5% had unilateral disease and 25.5% had bilateral disease. Of 297 patients with available data on disease and irradiation sides, 61 (20.5%) patients had unilateral disease and unilateral irradiation, 155 (52.2%), unilateral disease and bilateral irradiation and 81 (27.3%), bilateral disease and bilateral irradiation. Thirty-four (9.7%) and 217 (62.0%) patients received neoadjuvant and/or concomitant chemotherapy, respectively. Median follow-up was 37 months. Three-year local, regional, locoregional failure rates and CUP-specific survival were 5.6%, 11.7%, 15.0% and 84.7%, respectively. In patients with unilateral disease, the 3-year cumulative incidence of regional/local relapse was 7.7%/4.3% after bilateral irradiation versus 16.9%/11.1% after unilateral irradiation (hazard ratio = 0.56/0.61, p = 0.17/0.32). The cumulative incidence of CUP-specific deaths was 9.2% after bilateral irradiation and 15.5% after unilateral irradiation (p = 0.92). In multivariate analysis, mucosal irradiation was associated with better local control, whereas no neck dissection, ≥N2b and interruption of RT for more than 4 days were associated with poorer regional control. Toxicity was higher after bilateral irradiation (p < 0.05). No positron-emission tomography-computed tomography, largest node diameter, ≥N2b, neoadjuvant chemotherapy and interruption of RT were associated with poorer cause-specific survival.

CONCLUSION

Bilateral nodal irradiation yielded non-significant better nodal and mucosal control rates but was associated with higher rates of severe toxicity.

Dose-painting multicenter phase III trial in newly diagnosed glioblastoma: the SPECTRO-GLIO trial comparing arm A standard radiochemotherapy to arm B radiochemotherapy with simultaneous integrated boost guided by MR spectroscopic imaging

Background

Glioblastoma, a high-grade glial infiltrating tumor, is the most frequent malignant brain tumor in adults and carries a dismal prognosis. External beam radiotherapy (EBRT) increases overall survival but this is still low due to local relapses, mostly occurring in the irradiation field. As the ratio of spectra of choline/N acetyl aspartate> 2 (CNR2) on MR spectroscopic imaging has been described as predictive for the site of local relapse, we hypothesized that dose escalation on these regions would increase local control and hence global survival.

Methods/design

In this multicenter prospective phase III trial for newly diagnosed glioblastoma, 220 patients having undergone biopsy or surgery are planned for randomization to two arms. Arm A is the Stupp protocol (EBRT 60 Gy on contrast enhancement + 2 cm margin with concomitant temozolomide (TMZ) and 6 months of TMZ maintenance); Arm B is the same treatment with an additional simultaneous integrated boost of intensity-modulated radiotherapy (IMRT) of 72Gy/2.4Gy delivered on the MR spectroscopic imaging metabolic volumes of CHO/NAA > 2 and contrast-enhancing lesions or resection cavity. Stratification is performed on surgical and MGMT status.

Discussion

This is a dose-painting trial, i.e. delivery of heterogeneous dose guided by metabolic imaging. The principal endpoint is overall survival. An online prospective quality control of volumes and dose is performed in the experimental arm. The study will yield a large amount of longitudinal multimodal MR imaging data including planning CT, radiotherapy dosimetry, MR spectroscopic, diffusion and perfusion imaging.

Trial registration

NCT01507506, registration date December 20, 2011.

Molecular PET imaging in adaptive radiotherapy: brain

INTRODUCTION

Owing to their heterogeneity and radioresistance, the prognosis of primitive brain tumors, which are mainly glial tumors, remains poor. Dose escalation in radioresistant areas is a potential issue for improving local control and overall survival. This review focuses on advances in biological and metabolic imaging of brain tumors that are proving to be essential for defining tumor target volumes in radiation therapy (RT) and for increasing the use of DPRT (dose painting RT) and ART (adaptative RT), to optimize dose in radio-resistant areas.

EVIDENCE ACQUISITION

Various biological imaging modalities such as PET (hypoxia, glucidic metabolism, protidic metabolism, cellular proliferation, inflammation, cellular membrane synthesis) and MRI (spectroscopy) may be used to identify these areas of radioresistance. The integration of these biological imaging modalities improves the diagnosis, prognosis and treatment of brain tumors.

EVIDENCE SYNTHESIS

Technological improvements (PET and MRI), the development of research, and intensive cooperation between different departments are necessary before using daily metabolic imaging (PET and MRI) to treat patients with brain tumors.

CONCLUSIONS

The adaptation of treatment volumes during RT (ART) seems promising, but its development requires improvements in several areas and an interdisciplinary approach involving radiology, nuclear medicine and radiotherapy. We review the literature on biological imaging to outline the perspectives for using DPRT and ART in brain tumors.