Radiothérapie conformationnelle post opératoire à forte dose des cancers pulmonaires non à petites cellules (série rétrospective de 161 patients pris en charge au centre Léon Bérard entre 1994 et 2005)

LYON1-BU Santé (693882101) / SudocSudocFranceF

Stereotactic body radiation therapy in unresectable stage III non-small cell lung cancer: A systematic review

In unresectable stage III non-small cell lung cancer (NSCLC), the standard of care for most fit patients is concurrent chemotherapy with normofractionated radiotherapy (NFRT), followed by durvalumab consolidation. Nevertheless, almost half of patients will present locoregional or metastatic intrathoracic relapse. Improving locoregional control thus remains an important objective. For this purpose, stereotactic body radiotherapy (SBRT) may be a relevant treatment modality. We performed a systematic review of the literature that evaluate the efficacy and safety of SBRT in this situation, either instead of or in addition to NFRT. Among 1788 unique reports, 18 met the inclusion criteria. They included 447 patients and were mainly prospective (n = 10, including 5 phase 2 trials). In none, maintenance durvalumab was administered. Most reported SBRT boost after NFRT (n = 8), or definitive tumor and nodal SBRT (n = 7). Median OS varied from 10 to 52 months, due to the heterogeneity of the included populations and according to treatment regimen. The rate of severe side effects was low, with <5 % grade 5 toxicity, and mainly observed when mediastinal SBRT was performed without dose constraints to the proximal bronchovascular tree. It was suggested that a biologically effective dose higher than 112.3 Gy may increase locoregional control. SBRT for selected stage III NSCLC bears potential to improve loco-regional tumor control, but at present, this should only be done in prospective clinical trials

Harmonization of dose prescription for lung stereotactic radiotherapy

Background and purpose: Pulmonary stereotactic treatments can be performed using dedicated linear accelerators as well as robotic-assisted units, and different strategies can be used for dose prescription. This study aimed to compare the doses received by the tumor with a gross tumor volume (GTV)-based prescription on D98%GTV using a robotic-assisted unit (method A) and planning target volume (PTV)-based prescription on D95%PTV using a dedicated linac (method B). Material &amp; methods: Plans of 32 patients were collected for method A, and a dose of 3 × 18 Gy was prescribed using type A algorithm and recalculated using a Monte-Carlo (MC) algorithm. The plans were normalized to match D98%GTV with the mean D98%GTV¯ of the cohort. The plans of 23 patients were collected for method B, and a dose of 3 × 18 Gy was prescribed to D95%PTV using a MC algorithm. A 4D-sum method was developed to estimate doses for PTV and GTV. For validation, all plans were recalculated using an independent MC double-check software. A dose harmonization on D98% GTV was determined for both methods. Results: For method A, mean doses were D2%GTV = 59.9 ± 2.1 Gy, D50%GTV = 55.6 ± 1.2 Gy, D98%GTV = 49.5 ± 0.0 Gy. For method B, the reported doses were D2%GTV = 64.6 ± 2.1 Gy, D50%GTV = 62.8 ± 1.7 Gy, and D98%GTV = 60.0 ± 1.7 Gy. The dose trade-off of D98%GTV = 55 Gy was obtained for both methods. For method A, it corresponded to a dose prescription of 3 × 20 Gy using type A algorithm, followed by rescaling to obtain D98%GTV = 55 Gy. For method B, it corresponded to a dose prescription of D95%PTV = 3 × 16.5 Gy using the MC algorithm. Conclusions: This study determined similar near-minimum doses D98% GTV of approximately 3 × 18.3 Gy (55 Gy) using a GTV-based prescription on a robotic-assisted unit (method A) and a PTV-based prescription on a dedicated linac (method B)

Mid-p strategy versus ITV strategy in locally advanced lung cancer. A randomized phase II study

International audiencePurpose/Objective The overall survival (OS) of patients (pts) with non-resectable locally advanced non-small cell lung carcinoma (LA-NSCLC) is poor, in part due to insufficient local control (LC) using conformal irradiation techniques (RT). The personalization of the RT margins may impact the LC and the outcome. Internal Target Volume strategy (ITV) versus "Mid-position" strategy (Mid-p), was compared in a prospective non-comparative randomized monocentric phase II trial in NSCLC patients treated by definitive radiotherapy. Planning Target volumes and mean lung dose were previously reported as significantly reduced using the Mid-p strategy (DOI: 10.1259/bjr.20190692). We report here the clinical results. Material and Methods Eligible patients were randomized (2:1) to be treated with Mid-p or ITV strategies. Patients with proven LA-NSCLC, non-resected, non-metastatic treated by definitive RT could be included. The main objective was to evaluate the 1-year progression-free-survival (PFS) rate in the two arms. 36 pts were planned in the Mid-p arm, Fleming single-stage design (1-sided =0.1, 80% power, P0=30%, P1=50%). Secondary objectives were to evaluate 1-y and 2-y LC, OS and acute/middle term toxicity (NCI-CTCAE v4).Results 54 pts were randomized from 09/12 to 05/18. 3 patients finally did not receive radiotherapy and were excluded from the analysis. Median age was 65.2 y, 2/3 of the patients were male and had IIIA NSCLC stages, 31% received concomitant chemotherapy. 34 pts and 17 pts were included in the analysis in the Mid-p arm and ITV arm respectively. Median RT dose was 66 Gy in the Mid-p arm and 62 Gy in the ITV arm. Median PFS were 9.3 months and 10.3 months in the Mid-p arm and ITV arms respectively. 1-year PFS rate were 38% (1-sided CI95% = 25-) and 47% (CI95% = [27;[) in the Mid-p/ITV arm respectively. Efficacy in Mid-p arm is below that expected (starting hypothesis p0=30%, p1=50%). 2-year PFS rates were 15% (Mid-p) and 12% (ITV). 2-years LC rates were 65% (CI95% [48;81]) and 76% (CI95% [53;94]) in the Mid-p/ITV arms respectively. The analysis of the type of local failures (in field versus border of fields) is under analysis and will be available for the congress.No grade 4 or toxic deaths related to RT were reported. Grade 3 acute lung toxicity were reported in 12% and 23% in Mid-p and in ITV arms respectively. Grade 2 and Grade 3 late radiation fibrosis were reported in 29% and 15% respectively in the Mid-p arm, versus 23% and 29% using ITV strategy. Conclusion Two-year LC and PFS in LA-NSCLC seems similar in this non comparative Phase II randomized study using Mid-p or ITV strategies. The details of local relapses regarding RT fields and margins are under analysis and will be presented during the congress.Conflict of interest: this study was granted by Elekta

Feasibility of Stereotactic Body Radiation Therapy on Unresectable Stage III NSCLC with Peripheral Primary Tumor: A Prospective Study (GFPC 01-14)

International audienceConcomitant radiochemotherapy (RTCT) is the standard treatment for unresectable stage III non-small cell lung cancer (NSCLC). However, in patients with a peripheral primary tumor, the irradiated volume may include a large portion of normal lung and RT-CT is not possible. This multicenter phase II trial in unresectable stage III NSCLC with peripheral primary tumor evaluated the feasibility of stereotactic body radiation therapy (SBRT) in peripheral tumor after concomitant radio-chemotherapy (RT-CT). Nineteen patients were included and analyzed (median age, 60.9 years; male, 78%; adenocarcinoma, 74%; median size of peripheral primary tumor, 19 mm). At 6 months, the disease control rate was 79% (15/19). SBRT toxicity was generally mild with one (5%) patient having grade 3 lung toxicity. Recruitment for this study was stopped prior to completion, firstly due to the approval of adjuvant durvalumab after RT-CT, which was not anticipated in the design, and secondly due to the small number of stage III NSCLC patients with a peripheral tumor that was accessible to SBRT. Nevertheless, the combination of RT-CT and SBRT appeared to be feasible and safe

“Mid-P strategy” versus “internal target volume strategy in locally advanced non small cell lung cancer: Clinical results from the randomized non-comparative phase II study Mid-P

International audienc