Computational model based on optical coherence tomography (OCT) skin scanning to identify and quantify acute radiation dermatitis (ARD): a prospective diagnostic study.

BACKGROUND: acute radiation dermatitis (ARD) is the most widely reported radiotherapy-induced adverse event. Currently, there is no objective or reliable method to measure ARD. OBJECTIVE: our main objective was to identify and quantify the effects of radiotherapy with a computational model using optical coherence tomography (OCT) skin scanning. Secondary objectives included determining the ARD impact of different radiotherapeutic schemes and adjuvant topical therapies. METHODS: we conducted a prospective, single-center case series study in a tertiary referral center of patients with breast cancer who were eligible for whole breast radiotherapy (WBRT). RESULTS: a total of 39 women were included and distributed according to the radiotherapeutic schemes (15, 20, and 25 fractions). A computational model was designed to quantitatively analyze OCT findings. After radiotherapy, OCT scanning was more sensitive revealing vascularization changes in 84.6% of the patients (vs 69.2% of the patients with ARD by clinical examination). OCT quantified an increased vascularization at the end of WBRT (P < .05) and a decrease after 3 months (P = .032). Erythematous skin changes by OCT were more pronounced in the 25-fraction regime. CONCLUSION: an OCT computational model allowed for the identification and quantification of vascularization changes on irradiated skin, even in the absence of clinical ARD. This may allow the design of standardized protocols for ARD beyond the skin color of the patients involved.

Chronic toxicity and long-term outcome in intraoperative electron radiotherapy as boost followed by whole-breast irradiation.

PURPOSE: The administration of a dose boost to the tumor bed after breast-conserving surgery has proven to reduce local recurrence. Intra-operative electron radiotherapy (IOERT) offers an alternative method to deliver a boost with several advantages, such as direct visualization of the tumor bed, less inter- and intrafraction motion and a reduction in the number of medical appointments. The objective of our study is to assess chronic toxicity and long-term outcome for our patients after IOERT boost. MATERIAL AND METHODS: Forty-six patients treated at our institution between July 2013 and June 2020 with IOERT boost during Breast-Conserving Surgery and consecutive whole breast irradiation were prospectively analyzed. A 10-12 Gy boost was prescribed to 42 patients and 4 patients received a 20 Gy boost. An analysis for overall survival, local relapse and distant progression was performed. Acute and chronic toxicity was assessed by CTCAE 4.0. RESULTS: The median age was 64.5 years (40-90). The median follow-up was 62 months (4-86). We had no local recurrences but 2 patients (4.3%) presented a distant recurrence. Mean pathological tumor size was 16 mm (6-52). 84.8% (39) of the patients had invasive ductal carcinoma. 52.2% (24) presented histological grade II. 52.2% (24) were Luminal A like, 21.7% (10) Luminal B like, 13% (6) HER2 positive, 13% (6) triple negative. No Grade 3-4 chronic toxicity was observed. Grade 1-2 fibrosis was evidenced in 13% (6) of the patients, 4.3% (2) patients presented fat necrosis, 6.5% (3) presented seroma, 4.3% (2) had localized pain, 2.2% (1) presented localized hematoma and 2.2% (1) presented localized edema. CONCLUSIONS: IOERT boost in breast cancer treatment during BCS is a safe option with low chronic toxicity. The recurrence rates are comparable to published data and emphasize that IOERT as boost is an effective treatment.

Spanish validation of Charlson index applied to prostate cancer.

PURPOSE: Comorbidity assessment is essential in the triage of care for men with prostate cancer (PC). The aim of this study was to validate the Spanish version of the revised Charlson index (RCI) in PC. MATERIALS AND METHODS: 731 PC patients diagnosed from 1993 to 2008 were referred to our Radiation Oncology Department. The RCI classified patients into four categories RCI 0, RCI 1-2, RCI 3-4, and RCI 5 and higher. The Kaplan-Meier method and Cox proportional hazards modeling were used. We also analyzed the median age of patients who remained alive at the last control and those who died due to non-prostate cancer comorbidities. RESULTS: 636 patients were included median age: 70 years (44-85). The mean follow-up was 153.62 months, (6-288 months). Distribution of the D'Amico risk classification was 21%, 38.2%, and 40.8% for low, intermediate, and high risk, respectively. The RCI distribution categories were: 303 (46.7%) RCI 0, 102 (16%) RCI 1-2, 131 (20.6%) RCI 3-4, and 100 (15.7%) RCI 5 and higher. The probability of non-cause-specific mortality at 5 and 10 years was 2. 4% and 11.25% RCI 0, 3 and 14.1% RCI 1-2, 5.7% and 22.1% RCI 3-4, and 47% and 92% (RCI 5 and higher). The median age in the last control in patients alive or who had died by non-PC causes was 82.81 years (55.27-102). DISCUSSION: The RCI may be used to aid medical decision making in older Spanish men with PC, especially in those with a high RCI 5 and higher.

Postoperative adjuvant and very early salvage radiotherapy after prostatectomy in high-risk prostate cancer patients can improve specific and overall survival.

PURPOSE: Adjuvant radiotherapy (ART) for biochemical relapse (BR) after radical prostatectomy (RP) showed increased disease-free survival (DFS) in three previous randomized trials. Retrospective phase II trials evaluated if early salvage RT (ESRT) is equivalent to ART. Our study aims to compare ART and ESRT to salvage RT. MATERIALS AND METHODS: We compared RP plus ART and ESRT versus SRT. Indication for RT was made by PSA determination after RP: ART when PSA ≤ 0.2 ng/ml, ESRT when PSA ≤ 0.3 after PSA rise from 0.0 to SRT PSA ≥ 0.3. The cause of death of each patients was analyzed, DFS, cause-specific survival (CSS) overall survival (OS) and metastasis-free survival (MFS) in relation to RT intention. RESULTS: Between 1993 and 2008, 204 patients with a median age of 65 years (44-75) were treated. The median follow-up was 160 months (28.1-273.3). At diagnosis, 89.7% had localized clinical stages and 90.2% had Gleason (G) ≤ 7. The median PSA was 10 (range 4-101). The postoperative G was ≥ 7 in 66.2%; 56.4% had ≥ 2 positive margins; 29.4% received ART, 20% ESRT and 59.3% SRT. The DFS for ART, ESRT and SRT was 74, 56 and 39% with significant differences between the three groups (p < 0.001). ART + ESRT were combined versus SRT; for the DFS, the significant differences (p < 0.001) remained 67% versus 39%. Positive margins, pT3 and pre-RT PSA were significant factors on multivariate analysis. The CSS in the ART + ESRT group was 92 vs. 78% in the SRT group (p < 0.05). OS was 69% in ART + ESRT vs. 57% in SRT (p < 0.05). MFS was 82.7% in ART + ESRT vs. 67.4% in SRT. CONCLUSIONS: In this study the ART + ESRT presented benefits versus SRT in DFS, CSS, OS and MFS.

Fatty acid derivatives and their use as CFPP additives in biodiesel.

One of the main drawbacks of the use of biodiesel is its bad behavior at low temperatures. In this work, we show that it is possible to take profit of the presence of free fatty acids in the starting materials used for biodiesel production (i.e. reused oils) by synthesizing additives able to improve cold flow properties. The synthesis of fatty acid derivatives have been successfully carried out by esterification of stearic, oleic and linoleic acids with bulky linear and cyclic alcohols and by epoxidation of methyl oleate and subsequent ring-opening reaction with the same alcohols. The study of crystallization patterns of pure derivatives by DSC and optical microscopy revealed the improvement of cold properties of biodiesel. Blends of biodiesel with up to 5% of some of these compounds allowed a decrease of CFPP (Cold Filter Pour Point). Both observations reveal the utility of these compounds as cheap and renewable additives.