Introduction
With
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F-FDG PET/CT, tumor uptake intensity and heterogeneity have been associated with outcome in several cancers. This study aimed at investigating whether
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F-FDG uptake intensity, ...volume or heterogeneity could predict the outcome in patients with non-small cell lung cancers (NSCLC) treated by stereotactic body radiation therapy (SBRT).
Methods
Sixty-three patients with NSCLC treated by SBRT underwent a
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F-FDG PET/CT before treatment. Maximum and mean standard uptake value (SUVmax and SUVmean), metabolic tumoral volume (MTV), total lesion glycolysis (TLG), as well as 13 global, local and regional textural features were analysed. The predictive value of these parameters, along with clinical features, was assessed using univariate and multivariate analysis for overall survival (OS), disease-specific survival (DSS) and disease-free survival (DFS). Cutoff values were obtained using logistic regression analysis, and survivals were compared using Kaplan-Meier analysis.
Results
The median follow-up period was 27.1 months for the entire cohort and 32.1 months for the surviving patients. At the end of the study, 25 patients had local and/or distant recurrence including 12 who died because of the cancer progression. None of the clinical variables was predictive of the outcome, except age, which was associated with DFS (HR 1.1,
P
= 0.002). None of the
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F-FDG PET/CT or clinical parameters, except gender, were associated with OS. The univariate analysis showed that only dissimilarity (D) was associated with DSS (HR = 0.822,
P
= 0.037), and that several metabolic measurements were associated with DFS. In multivariate analysis, only dissimilarity was significantly associated with DSS (HR = 0.822,
P
= 0.037) and with DFS (HR = 0.834,
P
< 0.01).
Conclusion
The textural feature dissimilarity measured on the baseline
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F-FDG PET/CT appears to be a strong independent predictor of the outcome in patients with NSCLC treated by SBRT. This may help selecting patients who may benefit from closer monitoring and therapeutic optimization.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, VSZLJ, ZAGLJ
The primary objective of the present study was to identify a subset of radiomic features extracted from primary tumor imaged by computed tomography of early-stage non-small cell lung cancer patients, ...which remain unaffected by variations in segmentation quality and in computed tomography image acquisition protocol. The robustness of these features to segmentation variations was assessed by analyzing the correlation of feature values extracted from lesion volumes delineated by two annotators. The robustness to variations in acquisition protocol was evaluated by examining the correlation of features extracted from high-dose and low-dose computed tomography scans, both of which were acquired for each patient as part of the stereotactic body radiotherapy planning process. Among 106 radiomic features considered, 21 were identified as robust. An analysis including univariate and multivariate assessments was subsequently conducted to estimate the predictive performance of these robust features on the outcome of early-stage non-small cell lung cancer patients treated with stereotactic body radiation therapy. The univariate predictive analysis revealed that robust features demonstrated superior predictive potential compared to non-robust features. The multivariate analysis indicated that linear regression models built with robust features displayed greater generalization capabilities by outperforming other models in predicting the outcomes of an external validation dataset.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Our aim is to report treatment efficacy and toxicity of patients treated by robotic (Cyberknife®) stereotactic body radiotherapy (SBRT) for oligorecurrent lung metastases (ORLM). Additionally we ...wanted to evaluate influence of tumor, patient and treatment related parameters on local control (LC), lung and distant progression free- (lung PFS/Di-PFS) and overall survival (OS).
Consecutive patients with up to 5 ORLM (confirmed by FDG PET/CT) were included in this study. Intended dose was 60Gy in 3 fractions (prescribed to the 80% isodose volume). Patients were followed at regular intervals and tumor control and toxicity was prospectively scored. Tumor, patient and treatment data were analysed using competing risk- and Cox regression.
Between May 2010 and March 2016, 104 patients with 132 lesions were irradiated from primary lung carcinoma (47%), gastro-intestinal (34%) and mixed primary histologies (19%). The mean tumor volume was 7.9 cc. After a median follow up of 22 months, the 1, 2 and 3 year LC rate (per lesion) was 89.3, 80.0 and 77.8% respectively. The corresponding (per patient) 1, 2 and 3 years lung PFS were 66.3, 50.0, 42.6%, Di-PFS were 80.5, 64.4, 60.6% and OS rates were 92.2, 80.9 and 72.0% respectively. On univariable analysis, gastro-intestinal (GI) as primary tumor site showed a significant superior local control versus the other primary tumor sites. For OS, significant variables were primary histology and primary tumor site with a superior OS for patients with metastases of primary GI origin. LC was significantly affected by the tumor volume, physical and biologically effective dose coverage. Significant variables in multivariable analysis were BED prescription dose for LC and GI as primary site for OS. The vast majority of patients developed no toxicity or grade 1 acute and late toxicity. Acute and late grade 3 radiation pneumonitis (RP) was observed in 1 and 2 patients respectively. One patient with a centrally located lesion developed grade 4 RP and died due to possible RT-induced pulmonary hemorrhage.
SBRT is a highly effective local therapy for oligorecurrent lung metastases and could achieve long term survival in patients with favourable prognostic features.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To compare dose to organs at risk (OARs) and dose-escalation possibility for 24 stage I non-small cell lung cancer (NSCLC) patients in a ROCOCO (Radiation Oncology Collaborative Comparison) trial.
...For each patient, 3 photon plans Intensity-modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and CyberKnife, a double scattered proton (DSP) and an intensity-modulated carbon-ion (IMIT) therapy plan were created. Dose prescription was 60 Gy (equivalent) in 8 fractions.
The mean dose and dose to 2% of the clinical target volume (CTV) were lower for protons and ions compared with IMRT (p < 0.01). Doses to the lungs, heart, and mediastinal structures were lowest with IMIT (p < 0.01), doses to the spinal cord were lowest with DSP (p < 0.01). VMAT and CyberKnife allowed for reduced doses to most OARs compared with IMRT. Dose escalation was possible for 8 patients. Generally, the mediastinum was the primary dose-limiting organ.
On average, the doses to the OARs were lowest using particles, with more homogenous CTV doses. Given the ability of VMAT and CyberKnife to limit doses to OARs compared with IMRT, the additional benefit of particles may only be clinically relevant in selected patients and thus should be carefully weighed for every individual patient.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
•RO teaching is underrepresented in the curriculum of medical students in Europe.•RO is often taught and examined in modular courses.•E-learning, computer-based examination and OSCE are used in few ...institutions.•Clerkships and policies to enroll students in RO departments should be improved.
To provide an overview of Radiation Oncology (RO) teaching to medical students around Europe.
An electronic survey was sent to European academic teachers of RO. The survey focused on the teaching of RO to medical students throughout their undergraduate education.
A total of 87 academic RO teachers from 29 countries were invited to participate in the electronic survey. Thirty-two surveys were completed by respondents from 19 European countries (response rate: 37%). The median number of hours devoted to RO teaching was 10 h (mean 16 h, range 2–60). The number of hours assigned to RO teaching was equal or inferior compared to medical oncology. In two institutions (6%) RO was delivered as a stand-alone course with an individual knowledge assessment. In 30 institutions (94%), the RO course was taught and/or assessed in a modular curriculum with other disciplines. Radiobiology, breast, lung, gastrointestinal, gynecologic malignancies, RO adverse events and palliative RO were taught in 80% of institutions. Pediatric RO, RO for benign conditions and economic topics were taught in less than 30% of institutions. In most institutions, classical written and oral examinations were used. Computer-based examinations and/or objective structured clinical examinations (OSCE) were seldom used. E-learning methods were available in less than 10% of institutions. A clerkship in RO department was available in 28 out of 32 institutions (87%), less than 5% of medical students were involved in research in RO during their undergraduate education. Strategies to encourage medical students to consider RO as a future career were offered in 53% of institutions.
RO teaching to medical students was not uniform in Europe. RO teaching during undergraduate education in Europe was undervalued, and its knowledge and learning tools could be broadened and updated in the core curricula of medical students
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Impact of dosimetric parameters on efficacy of SBRT in ES-NSCLC, using HyTEC reporting standards.•A large cohort from a single institution to ensure consistent treatment methods.•This study could ...potentially resolve many errors that can occur in pooled studies.•A higher percent of GTV receiving ≥110 % of the prescribed dose and a higher GTV Dmax (BED10) seem to allow a better LC.•This is the first study to report the benefit of the percentage of GTV receiving ≥110 % of the prescribed dose on LC.
To evaluate the impact of dosimetric parameters on efficacy of stereotactic body radiation therapy (SBRT) in early-stage non-small cell lung cancer (ES-NSCLC), using Hypofractionated Treatment Effects in the Clinic (HyTEC) reporting standards.
From April 2010 to December 2020, 497 patients who received SBRT for ES-NSCLC at the University Hospital of Liège were retrospectively enrolled. A total dose of 40 to 60 Gy in 3–5 fractions (72–180 Gy biologically effective dose with an α/β ratio of 10 (BED10)) was prescribed to the 80 % isodose line of the PTV. Potential clinical and dosimetric predictors of recurrence, overall survival (OS) and disease specific survival (DSS) were evaluated using univariate and multivariate analyses.
After a median follow-up of 32 months (range 3–143 months), the local control and disease-free survival (DFS) rates at 3 years were 91 % (95 % CI: 90 %–93 %) and 75 % (95 % CI: 73 %–77 %), respectively. The median OS was 41.6 months and the median DSS was not reached. On multivariate analysis, a higher gross tumor volume (GTV) Dmax (BED10) (cut-off 198 Gy) and a larger percent of the GTV receiving ≥110 % of the prescribed dose were predictive of a better local control, only GTV volume was correlated with DSS and no parameter was correlated with OS and regional or distant recurrences.
Lung SBRT for ES-NSCLC in 3 to 5 fractions resulted in high local control rates. A higher percent of GTV receiving ≥110 % of the prescribed dose and a higher GTV Dmax (BED10) seem to allow a better local control.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We compared the dose conformity of two radiation modalities: high-dose-rate brachytherapy (HDR BT) and intensity-modulated radiation therapy (IMRT) to deliver a boost to the prostate after external ...beam radiotherapy (EBRT).
Ten successive patients with prostate adenocarcinoma treated with a single 10-Gy HDR BT boost after EBRT were investigated. Four theoretical IMRT plans were computed: (a) 32.85 Gy IMRT and (b) 26 Gy IMRT with CTV-PTV expansions, doses corresponding to the equivalent dose in 2-Gy fractions (EQD2) of one 10-Gy fraction calculated with a prostate alpha/beta ratio of respectively 1.5 and 3 Gy; and (c) 32.85 Gy IMRT and (d) 26 Gy IMRT without CTV-PTV expansions. The dose-volume histogram values converted in EQD2 with an alpha/beta ratio of 3 Gy for the organs at risk were compared.
The HDR BT plan delivered higher mean doses to the PTV compared with IMRT plans. In all, 33% of the rectal volume received a mean dose of 5.32 +/- 0.65 Gy and 20% of bladder volume received 4.61 +/- 1.24 Gy with HDR BT. In comparison, doses delivered with IMRT were respectively 13.4 +/- 1.49 Gy and 10.81 +/- 4 Gy, even if only 26 Gy was prescribed to the PTV with no CTV-PTV expansion (p < 0.0001). The hot spots inside the urethra were greater with HDR BT but acceptable.
Use of HDR BT produced a more conformal plan for the boost to the prostate than IMRT even without CTV-PTV expansions.
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GEOZS, IJS, NUK, OILJ, UL, UM, UPUK
The purpose of this study was to evaluate the effect of delay between planning computed tomography (CT) used as a basis for treatment planning and the start of treatment (delay planning treatment ...DPT), on local control (LC) for lung lesions treated by SABR.
We pooled 2 databases from 2 monocentric retrospective analysis previously published and added planning CT and positron emission tomography (PET)–CT dates. We analyzed LC outcomes based on DPT and reviewed all available cofounding factors among demographic data and treatment parameters.
A total of 210 patients with 257 lung lesions treated with SABR were evaluated. The median DPT was 14 days. Initial analysis revealed a discrepancy in LC as a function of DPT and a cutoff delay of 24 days (21 days for PET-CT almost systematically done 3 days after planning CT) was determined according to the Youden method. Cox model was applied to several predictors of local recurrence–free survival (LRFS). Univariate analysis showed LRFS decreasing significantly related to DPT ≥24 days (P = .0063), gross tumor volume, and clinical target volume (P = .0001 and P = .0022), but also with the presence of >1 lesion treated with the same planning CT (P = .024). LRFS increased significantly with higher biological effective dose (P < .0001). On multivariate analysis, LRFS remained significantly lower for lesions with DPT ≥24 days (hazard ratio, 2.113; 95% confidence interval, 1.097-4.795; P = .027).
DPT to SABR treatment delivery for lung lesions appears to reduce local control. Timing from imaging acquisition to treatment delivery should be systematically reported and tested in future studies. Our experience suggests that the time from planning imaging to treatment should be <21 days.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Authors report clinical outcomes of patients treated with robotic stereotactic body radiotherapy (SBRT) for primary, recurrent and metastatic lung lesions.
130 patients with 160 lesions were treated ...with Cyberknife SBRT, including T1-3 primary lung cancers (54%), recurrent tumors (22%) and pulmonary metastases (24%). The mean biologically equivalent dose (BED
was 151 Gy (72-180 Gy). Median prescribed dose for peripheral and central lesions was 3×20 Gy and 3×15 Gy, respectively. Local control (LC), overall survival (OS), and cause-specific survival (CSS) rates, early and late toxicities are reported. Statistical analysis was performed to identify factors influencing local tumor control.
Median follow-up time was 21 months. In univariate analysis, higher dose was associated with better LC and a cut-off value was detected at BED
≤ 112.5 Gy, resulting in 1-, 2-, and 3-year actuarial LC rates of 93%, vs 73%, 80% vs 61%, and 63% vs 54%, for the high and low dose groups, respectively (p = 0.0061, HR = 0.384). In multivariate analysis, metastatic origin, histological confirmation and larger Planning Target Volume (PTV) were associated with higher risk of local failure. Actuarial OS and CSS rates at 1, 2, and 3 years were 85%, 74% and 62%, and 93%, 89% and 80%, respectively. Acute and late toxicities ≥ Gr 3 were observed in 3 (2%) and 6 patients (5%), respectively.
Our favorable LC and survival rates after robotic SBRT, with low rates of severe toxicities, are coherent with the literature data in this mixed, non-selected study population.
Purpose or Objective :
Report our experience of fractionated stereotactic radiotherapy Cyberknife (CK) for vestibular schwannoma (VS) in order to asses the posttreatment clinical symptoms, tumor ...control and post treatment auditory function.
Materials and Methods :
Retrospective analysis of 45 VS patients treated by CK from 2010 to 2016, classified in location and size according to Portman-Bebear and Koos (PBK) and according to 2 audiometric scales: the International Bureau of Audiophonology (BIAP) and the Gardner Robertson scale (GR). Data including CK treatment parameters, pre and post CK clinical signs, pre and post CK tumor volumes and auditory parameters were collected and examinated.
Results : 80% of the pre CK clinical symptoms of our 45 patients improve in post-CK and 20% increase slightly. 77.3% of patients, with a mean post CK magnetic resonance imaging (MRI) follow-up of 31.5 months, had an excellent tumor control. Excluding 2 patients who died in post CK and 8 pre CK cophosis patients, 21 (60%) of the remaining 35 BIAP patients, with a mean audiometric post CK follow-up of 33.65 months, maintained a good pre CK comparable audiometric stabilization. The other fourteen BIAP patients (40%) experienced variable hearing impairment (33.3% had slight increased hearing thresholds from 10 to 24dB in pure tone audiometry) which is not related to a pre CK high tumor volume (tV).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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