Effect of internal port on dose distribution in post-mastectomy radiotherapy for breast cancer patients after expander breast reconstruction.

Background: In patients with expander-based reconstruction a few dosimetric analyses detected radiation therapy dose perturbation due to the internal port of an expander, potentially leading to toxicity or loss of local control. This study aimed at adding data on this field. Materials and methods: A dosimetric analysis was conducted in 30 chest wall treatment planning without and with correction for port artifact. In plans with artifact correction density was overwritten as 1 g/cm3. Medium, minimum and maximum chest wall doses were compared in the two plans. Both plans, with and without correction, were compared on an anthropomorphic phantom with a tissue expander on the chest covered by a bolus simulating the skin. Ex vivo dosimetry was carried out on the phantom and in vivo dosimetry in three patients by using film strips during one treatment fraction. Estimated doses and measured film doses were compared. Results: No significant differences emerged in the minimum, medium and maximum doses in the two plans, without and with correction for port artifacts. Ex vivo and in vivo analyses showed a good correspondence between detected and calculated doses without and with correction. Conclusions: The port did not significantly affect dose distribution in patients who will receive post-mastectomy radiation therapy.

FDG-PET/CT in the Radiotherapy Treatment Planning of Locally Advanced Anal Cancer: A Monoinstitutional Experience.

AIMS: Radiotherapy with concurrent 5-fluorouracil/mitomycin-C based chemotherapy has been established as definitive standard therapy approach for anal cancer. Intensity Modulated Radiotherapy (IMRT) leads to a precise treatment of the tumor, allowing dose escalation on Gross Tumor Volume (GTV), with a surrounding healthy tissues sparing. Our study assessed the impact of 18-Fluorodeoxyglucose positron emission tomography (18FDG-PET/CT) on the radiotherapy contouring process and its contribution to lymphatic spread detection, resulting to a personalization of Clinical Target Volume (CTV) and dose prescription. METHODS: Thirty-seven patients, with histologically proven squamous cell carcinoma of the anal canal (SCCAC) were analyzed. All patients were evaluated with history and physical examination, trans-anal endoscopic ultrasound, pelvis magnetic resonance imaging (MRI), computed tomography (CT) scans of the chest, abdomen and pelvis and planning 18FDG-PET/CT. The GTV and CTV were drawn on CT, MRI and 18FDG-PET/CT fused images. RESULTS: Thirty-four (91%) out of 37 patients presented lymph nodes involvement, in one or more areas, detected on 18FDG-PET/CT and/or MRI. The 18FDG-PET/CT showed positive lymph nodes not detected on MRI imaging (PET+, MRI-) in 14/37 patients (38%). In 14 cases, 18FDG-PET/CT allowed to a dose escalation in the involved nodes. The 18FDG-PET/CT fused images led to change the stage in 5/37(14%) cases: four cases from N0 to N1 (inguinal lymph nodes) and in one case from M0 to M1 (common iliac lymph nodes). CONCLUSIONS: The 18FDG-PET/CT has a potentially relevant impact in staging and target volume delineation/definition in patients affected by anal cancer. In our experience, clinical stage variation occurred in 14% of cases. More investigations are needed to define the role of 18FDG-PET/CT in the target volume delineation of anal cancer.

Advanced head and neck cancer in older adults: Results of a short course accelerated radiotherapy trial.

OBJECTIVES: To assess the feasibility and safety of a repeated SHort course Accelerated RadiatiON therapy (SHARON) regimen in the palliative setting of Head and Neck (H&N) cancer in older adults. MATERIAL AND METHODS: Patients with histological confirmed H&N cancers, age ≥ 80 years, expected survival >3 months, and Eastern Cooperative Oncology Group (ECOG) performance status of ≤3 were enrolled. Patients were treated in cohorts of six patients: a total dose of 20 Gy was delivered in 2 consecutive days with a twice-daily fractionation (5 Gy per fraction) and at least 8-h interval. If no Grade 3 toxicity was registered, a second enrollment started with another cohort of six patients to whom were administered two cycles (total dose of 40 Gy). The primary endpoint was to evaluate the feasibility of the two cycles of treatment. Secondary endpoints were evaluation of symptoms control rate, symptoms-free survival (SFS), and Quality of Life (QoL) scores. RESULTS: Seventeen consecutive patients (median age: 85 years) were treated. Nine patients were treated with one cycle and 8 patients with two cycles. No G3 toxicity was reported in either cohort. With a median follow-up time of 4 months, 3-month SFS in the first and second cohorts was 83.3%, and 87.5%, respectively. The overall palliative response rate was 88%. Among 13 patients reporting pain, 8 (61.5%) showed an improvement or resolution of their pain. CONCLUSION: Repeated short course accelerated radiotherapy in a palliative setting of H&N cancers is safe and well-tolerated in older adults.

Efficacy and safety of 3D-conformal half body irradiation in patients with multiple bone metastases.

Half-body irradiation (HBI) represented a standard treatment for multiple painful bone metastases (BMs). However, its use has progressively reduced due to the associated toxicity rates. The aim of this paper was to evaluate HBI delivered by conformal radiotherapy (RT) technique in a large patients population with widespread BMs. HBI was delivered in 3 Gy fractions, bid, ≥ 6 h apart, on 2 consecutive days (total dose: 12 Gy) using 3-dimensional conformal RT (3D-CRT) box technique. The target included pelvic bones, lumbar-sacral vertebrae and upper third of femurs. Acute and late toxicity was scored based on RTOG and EORTC-RTOG scales, respectively. Pain was evaluated using the Pain-Drug scores and the Visual Analog Scale (VAS). One hundred and eighty patients were eligible for inclusion in this retrospective analysis. Grade 3 and 4 acute toxicity rates were 1.1% and 0.0%, respectively. Mean VAS before and after HBI was 5.3 versus 2.7, respectively (p: 0.0001). Based on VAS, 37.5% of patients showed complete pain relief (VAS: 0) while 38.1% had partial response (≥ 2-point VAS reduction). Overall, Pain and Drug Score reduction was observed in 76.3% and 50.4% of patients, respectively. 1-, 2-, and 3-year pain progression free survival was 77.0%, 63.4%, and 52.7%, respectively. Thirty patients (16.7%) underwent RT retreatment on the same site with median 15.9 months interval (range 2-126 months). HBI delivered with 3D-CRT technique is safe and effective. It provides long lasting pain control in patients with multiple BMs with negligible rates of relevant toxicity.

Statins Protect Against Acute RT-related Rectal Toxicity in Patients with Prostate Cancer: An Observational Prospective Study.

AIM: To analyze risk factors for acute rectal toxicity during hypofractionated intensity-modulated radiotherapy (IMRT) for prostate cancer. PATIENTS AND METHODS: A total of 195 patients received 74.25 Gy in 33 fractions to the prostate and, if involved, to the seminal vescicles (SV). When the risk of SV involvement was >15% according to the Roach's formula, they received 62 Gy in 33 fractions. Overall, 107/195 patients (54.87%) received hormonal therapy (luteinizing hormone-releasing hormone analogue, anti-androgen, or both). Common Terminology Criteria for Adverse Events version 3.0 was used to classify rectal toxicity. RESULTS: Acute rectal toxicity occurred in 79 (40.51%) patients (grade 1 in 44). In univariate analysis, use of calcium channel blockers significantly reduced the acute rectal toxicity rate and 3-hydroxy-methylglutaryl CoA reductase inhibitors (statins) significantly reduced the rectal toxicity rate and grade. In multivariate analysis, only statin use was an independent protective factor. CONCLUSION: In patients with prostate cancer treated with a moderate hypofractionated IMRT schedule, use of statins lowered the incidence and grade of acute rectal toxicity.

Motor-Skill Learning in an Insect Inspired Neuro-Computational Control System.

In nature, insects show impressive adaptation and learning capabilities. The proposed computational model takes inspiration from specific structures of the insect brain: after proposing key hypotheses on the direct involvement of the mushroom bodies (MBs) and on their neural organization, we developed a new architecture for motor learning to be applied in insect-like walking robots. The proposed model is a nonlinear control system based on spiking neurons. MBs are modeled as a nonlinear recurrent spiking neural network (SNN) with novel characteristics, able to memorize time evolutions of key parameters of the neural motor controller, so that existing motor primitives can be improved. The adopted control scheme enables the structure to efficiently cope with goal-oriented behavioral motor tasks. Here, a six-legged structure, showing a steady-state exponentially stable locomotion pattern, is exposed to the need of learning new motor skills: moving through the environment, the structure is able to modulate motor commands and implements an obstacle climbing procedure. Experimental results on a simulated hexapod robot are reported; they are obtained in a dynamic simulation environment and the robot mimicks the structures of Drosophila melanogaster.