Primary tumors of the lung: should we consider thermal ablation as a valid therapeutic option?

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer death; percutaneous thermal ablation (TA) has proven feasibility, good local control and good tolerance in stage I tumors for patients with medical comorbidities and who are ineligible for surgery. In this context, stereotactic body radiotherapy (SBRT) has demonstrated high efficacy in treating T1 NSCLC and will need to be compared with percutaneous ablation. TA is also indicated in oligoprogressive disease; and can be proposed as a salvage treatment option for tumor recurrence after radiotherapy. Besides more advanced NSCLC could be also an indication of TA in combination with systemic treatments. A large majority of diagnosed NSCLC do not exhibit specific targetable genetic aberration. Those tumors present poorer prognosis and have been treated with standard chemotherapy regimen until the recent development of immune checkpoint inhibitors (ICIs) based immunotherapy. Combining TA with immunotherapy is promising and still needs to be explored.

Percutaneous lung thermal ablation of non-surgical clinical N0 non-small cell lung cancer: results of eight years' experience in 87 patients from two centers.

PURPOSE: To evaluate the survival outcomes of percutaneous thermal ablation (RFA + microwaves) for patients presenting N0 non-small-cell lung cancer (NSCLC) ineligible for surgery. MATERIALS AND METHODS: Eighty-seven patients from two comprehensive cancer centers were included. Eighty-two patients were treated with RFA electrodes and five with microwave antenna. Overall survival (OS) and disease-free survival (DFS) were estimated and predictive factors of local tumor progression, OS and DFS identified and compared by univariate and multivariate analyses RESULTS: Median follow-up was 30.5 months (interquartile range 16.7-51) and tumor size was 21 mm (range 10-54 mm). Treatment was incomplete for 14 patients with a local tumor progression of 11.5, 18.3, and 21.1 % at 1, 2, and 3 years, respectively. Two patients presented with neurological (grade III or IV) complications, and one died of respiratory and multivisceral failure as a result of the procedure at 29 days. In univariate analysis, increasing tumor size (P = 0.003) was the only predictive factor related to risk of local tumor progression. 5-year OS and DFS were 58.1 and 27.9 %, respectively. Sex (P = 0.044), pathology (P = 0.032), and tumor size >2 cm (P = 0.046) were prognostic factors for DFS. In multivariate analysis, pathology (P = 0.033) and tumor size >2 cm (P = 0.032) were independent prognostic factors for DFS. CONCLUSIONS: Oversized and overlapping ablation of N0 NSCLC was well tolerated, effective, with few local tumor progressions, even over long-term follow-up. Increasing tumor size was the main prognostic factor linked to OS, DFS, and local tumor progression.

Surgical resection and radiotherapy for primary retroperitoneal soft tissue sarcoma.

METHODS AND MATERIALS: Forty-five patients were consecutively treated for primary retroperitoneal soft tissue sarcoma with surgery in combination with radiation therapy in the same institution. The median follow-up time was 53 months (7-108). RESULTS: Seventeen (38%) patients had clear microscopic margins (R0 resection), 26 patients (58%) had gross complete surgical excision (R1 resection) and two patients (4%) had a macroscopic residual disease (R2 resection). External radiotherapy doses ranged from 40.8 to 59.4 Gy (mean and median: 49 Gy). Seventeen patients underwent intraoperative radiation therapy (IORT). Moreover, 11 patients received chemotherapy. The overall 1-, 2-, and 5-year survival for all 45 patients were 93, 85 and 60%, respectively. The 1-, 2-, and 5-year locoregional relapse-free rate for the whole group was 91, 70 and 40%, respectively. In univariate analysis, quality of surgery was the only variable to show a significant effect for overall survival (P=0.0386) and for local control (P=0.0059). Tumor size and tumor grade had no statistically significant effect. For the patients receiving IORT+external beam radiation therapy, no difference was observed for survival or locoregional control. The most frequent acute side effects treatment complications were radiation-induced nausea or vomiting (42%) and moderate enteritis (30%). Significant late morbidity was observed for two patients. CONCLUSIONS: This study confirms the feasibility of external postoperative radiotherapy with an acceptable level of toxicity. However, the high rate of local relapses (especially in field of radiation) does not demonstrate the usefulness of radiotherapy at the level of dose used and further preferably randomized studies should be planned.

Zenithal gliding of the easy axis of a nematic liquid crystal.

We present experimental evidence of zenithal gliding of the nematic easy axis on a polyimide surface. The reorientation dynamics of the easy axis under external torque, and its relaxation, are extremely slow processes which cannot be described by a single exponential time. They show similarities with aging phenomena previously encountered in glassy systems. At last, the adsorption-desorption-readsorption process which empirically justifies the azimuthal easy axis gliding may also explain our observations.

Brain metastases from thyroid carcinoma: a retrospective study of 21 patients.

BACKGROUND: Brain metastases (BM) from differentiated thyroid carcinoma (DTC) are uncommon, and many questions about their management remain unsolved. The objective of this retrospective study was to analyze the characteristics, treatments, and outcomes of patients with BM from DTC. METHODS: Among the 1523 patients with a DTC prospectively recorded in institutional databases between 1989 and 2012, 21 patients (1.4%) with BM were retrospectively retrieved. Patient characteristics, histological findings on initial thyroidectomy specimen, treatments, and time to death were reviewed. Overall survival (OS) was calculated using the Kaplan-Meier method. Survival curves for various subgroups of patients according to baseline characteristics and treatment received were compared. RESULTS: The mean age at initial and BM diagnosis was, respectively, 52.7 and 63.2 years. World Health Organization performance status (PS) at BM diagnosis was good (<2) for 12 patients and poor (≥2) for 9. The initial carcinoma was papillary for 12 patients, follicular for 5, and poorly differentiated for 4. Eighteen patients had other previous and/or synchronous distant metastases: lung (11), bone (10), and others (2 peritoneum, 1 liver, 1 adrenal gland, and 1 uterine cervix). The average interval between the first metastasis and the BM was 3 years (range 0-35.6 years). The mean number and the mean size of BM were, respectively, 2.8 (range 1-10) and 22.5 mm (range 3-44 mm). Surgery was performed for 10 patients and radiotherapy (RT) for 18, with 2 stereotactic radiosurgery (SRS), 2 conformal RT limited to the metastasis, and 15 whole-brain RT. The median OS after BM was 7.1 months. OS at 1 and 2 years were 41.6% and 35.6%. PS and realization of surgery or SRS had an impact on survival, with OS of 27 months when PS <2 versus 3 months when PS ≥2 (p=0.0009), and OS of 11.9 months after surgery or SRS versus 3.6 months in their absence (p=0.04). CONCLUSIONS: BM from thyroid cancer may have an indolent evolution with survival of one to two years or longer for specific groups of patients. Therefore, aggressive treatment options such as neurosurgery and RT should be strongly considered in patients with good PS.

Use of FDG-PET to guide dose prescription heterogeneity in stereotactic body radiation therapy for lung cancers with volumetric modulated arc therapy: a feasibility study.

BACKGROUND: The aim of this study was to assess if FDG-PET could guide dose prescription heterogeneity and decrease arbitrary location of hotspots in SBRT. METHODS: For three patients with stage I lung cancer, a CT-simulation and a FDG-PET were registered to define respectively the PTVCT and the biological target volume (BTV). Two plans involving volumetric modulated arc therapy (VMAT) and simultaneous integrated boost (SIB) were calculated. The first plan delivered 4 × 12 Gy within the PTV(CT) and the second plan, with SIB, 4 × 12 Gy and 13.8 Gy (115% of the prescribed dose) within the PTV(CT) and the BTV respectively. The Dmax-PTV(CT) had to be inferior to 60 Gy (125% of the prescribed dose). Plans were evaluated through the D95%, D99% and Dmax-PTV(CT), the D2 cm, the R50% and R100% and the dice similarity coefficient (DSC) between the isodose 115% and BTV. DSC allows verifying the location of the 115% isodose (ideal value = 1). RESULTS: The mean PTV(CT) and BTV were 36.7 (±12.5) and 6.5 (±2.2) cm3 respectively. Both plans led to similar target coverage, same doses to the OARs and equivalent fall-off of the dose outside the PTV(CT). On the other hand, the location of hotspots, evaluated through the DSC, was improved for the SIB plans with a mean DSC of 0.31 and 0.45 for the first and the second plans respectively. CONCLUSIONS: Use of PET to decrease arbitrary location of hotspots is feasible with VMAT and SIB for lung cancer.

Comparison between CT- and FDG-PET-defined target volumes for radiotherapy planning in head-and-neck cancers.

Nine patients with head-and-neck cancer underwent computerized tomography (CT) simulation and [(18)F]-fluorodeoxyglucose positron emission tomography (FDG-PET) to compare the radiotherapy target volumes. The PET volumes were delineated with an automatic segmentation based on the source-to-background ratio. The volume comparison showed a reduction and qualitative discrepancies between the PET- and CT-volumes.

[The cost of intensity modulated radiation therapy in head and neck cancers: results of the 2002 STIC study]. / Le coût de la radiothérapie conformationnelle avec modulation d'intensité dans les cancers ORL: l'étude STIC 2002.

An economic evaluation of intensity modulated radiotherapy (IMRT) in head and neck cancer was carried out to assess the cost of treatment and compare it to reimbursement paid to hospitals in the French Prospective Payment System. Planning required in average 20 hours of work for the physician and 6 hours for the radiation oncologist. Radiation consisted of 33 fractions in average and required 29 hours of work for the radiotherapy technician, 8 hours for the physician and 3 hours for the radiation oncologist. Mean cost of IMRT treatment was estimated at euro 10,916 (euro 2,773 for planning and euro 8,143 for radiation). The variability of costs was important and was in a large extent attributable to learning effects. As more patients were treated, unit cost of treatment was decreasing. In the French Prospective Payment System, mean reimbursement of IMRT was euro 6,987. For 70 % of the patients, reimbursement did not offset the cost of treatment. A financial support for hospitals implementing the technique is essential during the whole learning period.