Recommendations for improved reproducibility of ADC derivation on behalf of the Elekta MRI-linac consortium image analysis working group.

BACKGROUND AND PURPOSE: The apparent diffusion coefficient (ADC), a potential imaging biomarker for radiotherapy response, needs to be reproducible before translation into clinical use. The aim of this study was to evaluate the multi-centre delineation- and calculation-related ADC variation and give recommendations to minimize it. MATERIALS AND METHODS: Nine centres received identical diffusion-weighted and anatomical magnetic resonance images of different cancerous tumours (adrenal gland, pelvic oligo metastasis, pancreas, and prostate). All centres delineated the gross tumour volume (GTV), clinical target volume (CTV), and viable tumour volume (VTV), and calculated ADCs using both their local calculation methods and each of the following calculation conditions: b-values 0-500 vs. 150-500 s/mm2, region-of-interest (ROI)-based vs. voxel-based calculation, and mean vs. median. ADC variation was assessed using the mean coefficient of variation across delineations (CVD) and calculation methods (CVC). Absolute ADC differences between calculation conditions were evaluated using Friedman's test. Recommendations for ADC calculation were formulated based on observations and discussions within the Elekta MRI-linac consortium image analysis working group. RESULTS: The median (range) CVD and CVC were 0.06 (0.02-0.32) and 0.17 (0.08-0.26), respectively. The ADC estimates differed 18% between b-value sets and 4% between ROI/voxel-based calculation (p-values < 0.01). No significant difference was observed between mean and median (p = 0.64). Aligning calculation conditions between centres reduced CVC to 0.04 (0.01-0.16). CVD was comparable between ROI types. CONCLUSION: Overall, calculation methods had a larger impact on ADC reproducibility compared to delineation. Based on the results, significant sources of variation were identified, which should be considered when initiating new studies, in particular multi-centre investigations.

Automatic AI-based contouring of prostate MRI for online adaptive radiotherapy.

BACKGROUND AND PURPOSE: MR-guided radiotherapy (MRgRT) online plan adaptation accounts for tumor volume changes, interfraction motion and thus allows daily sparing of relevant organs at risk. Due to the high interfraction variability of bladder and rectum, patients with tumors in the pelvic region may strongly benefit from adaptive MRgRT. Currently, fast automatic annotation of anatomical structures is not available within the online MRgRT workflow. Therefore, the aim of this study was to train and validate a fast, accurate deep learning model for automatic MRI segmentation at the MR-Linac for future implementation in a clinical MRgRT workflow. MATERIALS AND METHODS: For a total of 47 patients, T2w MRI data were acquired on a 1.5 T MR-Linac (Unity, Elekta) on five different days. Prostate, seminal vesicles, rectum, anal canal, bladder, penile bulb, body and bony structures were manually annotated. These training data consisting of 232 data sets in total was used for the generation of a deep learning based autocontouring model and validated on 20 unseen T2w-MRIs. For quantitative evaluation the validation set was contoured by a radiation oncologist as gold standard contours (GSC) and compared in MATLAB to the automatic contours (AIC). For the evaluation, dice similarity coefficients (DSC), and 95% Hausdorff distances (95% HD), added path length (APL) and surface DSC (sDSC) were calculated in a caudal-cranial window of ± 4 cm with respect to the prostate ends. For qualitative evaluation, five radiation oncologists scored the AIC on the possible usage within an online adaptive workflow as follows: (1) no modifications needed, (2) minor adjustments needed, (3) major adjustments/ multiple minor adjustments needed, (4) not usable. RESULTS: The quantitative evaluation revealed a maximum median 95% HD of 6.9 mm for the rectum and minimum median 95% HD of 2.7 mm for the bladder. Maximal and minimal median DSC were detected for bladder with 0.97 and for penile bulb with 0.73, respectively. Using a tolerance level of 3 mm, the highest and lowest sDSC were determined for rectum (0.94) and anal canal (0.68), respectively. Qualitative evaluation resulted in a mean score of 1.2 for AICs over all organs and patients across all expert ratings. For the different autocontoured structures, the highest mean score of 1.0 was observed for anal canal, sacrum, femur left and right, and pelvis left, whereas for prostate the lowest mean score of 2.0 was detected. In total, 80% of the contours were rated be clinically acceptable, 16% to require minor and 4% major adjustments for online adaptive MRgRT. CONCLUSION: In this study, an AI-based autocontouring was successfully trained for online adaptive MR-guided radiotherapy on the 1.5 T MR-Linac system. The developed model can automatically generate contours accepted by physicians (80%) or only with the need of minor corrections (16%) for the irradiation of primary prostate on the clinically employed sequences.

Impact of endorectal filling on interobserver variability of MRI based rectal primary tumor delineation.

Background: Online adaptive MR-guided radiotherapy allows for the reduction of safety margins in dose escalated treatment of rectal tumors. With the use of smaller margins, precise tumor delineation becomes more critical. In the present study we investigated the impact of rectal ultrasound gel filling on interobserver variability in delineation of primary rectal tumor volumes. Methods: Six patients with locally advanced rectal cancer were scanned on a 1.5 T MRI-Linac without (MRI_e) and with application of 100 cc of ultrasound gel transanally (MRI_f). Eight international radiation oncologists expert in the treatment of gastrointestinal cancers delineated the gross tumor volume (GTV) on both MRI scans. MRI_f scans were provided to the participating centers after MRI_e scans had been returned. Interobserver variability was analyzed by either comparing the observers' delineations with a reference delineation (approach 1) and by building all possible pairs between observers (approach 2). Dice Similarity Index (DICE) and 95 % Hausdorff-Distance (95 %HD) were calculated. Results: Rectal ultrasound gel filling was well tolerated by all patients. Overall, interobserver agreement was superior in MRI_f scans based on median DICE (0.81 vs 0.74, p < 0.005 for approach 1 and 0.76 vs 0.64, p < 0.0001 for approach 2) and 95 %HD (6.9 mm vs 4.2 mm for approach 1, p = 0.04 and 8.9 mm vs 6.1 mm, p = 0.04 for approach 2). Delineated median tumor volumes and inter-quartile ranges were 26.99 cc [18.01-50.34 cc] in MRI_e and 44.20 [19.72-61.59 cc] in MRI_f scans respectively, p = 0.012. Conclusions: Although limited by the small number of patients, in this study the application of rectal ultrasound gel resulted in higher interobserver agreement in rectal GTV delineation. The endorectal gel filling might be a useful tool for future dose escalation strategies.

Online MR guided dose escalated radiotherapy for organ preservation in distal rectal cancer.

Introduction: Non-surgical management of rectal cancer aiming for organ-preservation is an important development to improve rectal cancer treatment. Dose escalated radiotherapy represents one approach to increase clinical complete response (cCR) rates. In the present study we present feasibility and outcome data on rectal cancer patients who were treated with dose escalated radiotherapy using an MR guided online response-adaptive workflow. Material and methods: A total of five patients were treated with 45 Gy in 25 fractions to the mesorectum and the internal iliac lymph nodes and a simultaneous integrated boost to the primary tumor with 50 Gy in 25 fractions on a conventional linac. In addition, weekly response-adaptive boost fractions with 3 Gy per fraction were scheduled on a 1.5 T MR-Linac. Concomitant chemotherapy with 5-fluorouracil was given as continuous venous infusion during the first and last week of treatment. Response was evaluated approximately-three months after the end of treatment and surgery was omitted in case of a clinical complete response (cCR) or a near cCR. Toxicity was graded by using PRO-CTCAE, Quality of life by the EORTC-QLQ-C30 questionnaire and continence according to the Wexner scale. Results: Response-adaptive dose escalated radiotherapy was feasible and well tolerated by all patients. Four reached a clinical complete response, one had a local excision confirming pathological complete response (pCR). All PRO-CTCAE grade 3 toxicities resolved within six months after the end of treatment. Quality of life and continence scores during follow-up were comparable to baseline levels. Conclusion: Dose-escalated online response-adaptive MR-guided radiotherapy appears to be a very promising treatment with the goal of organ preservation in rectal cancer leading to high response rates, excellent organ function and limited side effects. Further prospective evaluation is needed.

A novel approach for radiotherapy dose escalation in rectal cancer using online MR-guidance and rectal ultrasound gel filling - Rationale and first in human.

INTRODUCTION: Dose escalated radiotherapy has previously been investigated as a strategy to increase complete response rates in rectal cancer. However large safety margins are required using cone-beam computed tomography guided radiotherapy leading to high doses to organs at risk or insufficient target volume coverage in order to keep dose constraints. We herein present the first clinical application of a new technique for dose escalation in rectal cancer using online magnetic resonance (MR)-guidance and rectal ultrasound gel filling. METHODS: A 73-year-old patient with distal cT3a cN0 cM0 rectal cancer was referred for definitive radiochemotherapy with the goal of organ preservation after multidisciplinary discussion. A dose of 45 Gy in 25 fractions with a stereotactic integrated boost to the primary tumor of 50 Gy with concomitant 5-fluorouracil was prescribed. Furthermore, a boost to the primary tumor with 3 Gy per fraction using the adapt-to-shape workflow on a 1.5 T MR-Linac was planned once weekly. For the boost fractions 100 cc of ultrasound gel was applied rectally in order to improve tumor visibility and distancing of uninvolved rectal mucosa. In order to determine the required planning target volume margin diagnostic scans of ten rectal cancer patients conducted with rectal ultrasound gel filling were studied. RESULTS: Based on the ten diagnostic scans an average isotropic margin of 4 mm was found to be sufficient to cover 95% of the target volume during an online adaptive workflow. Three boost fractions were applied, mean treatment duration was 22:34 min. Treatment was well tolerated by the patient with no more than PRO-CTCAE grade I° toxicity of any kind. The rectal ultrasound gel filling resulted in superior visibility of the tumor and reduced the dose to the involved mucosa especially in the high dose range compared with a boost plan calculated without any filling. A considerable tumor shrinkage was observed during treatment from 17.43 cc at baseline to 4 cc in week four. CONCLUSION: This novel method appears to be a simple but effective strategy for dose escalated radiotherapy in rectal cancer. Based on the encouraging observation, a prospective trial is currently under preparation.

1.5 T MR-linac planning study to compare two different strategies of rectal boost irradiation.

PURPOSE: To compare treatment plans of two different rectal boost strategies: up-front versus adaptive boost at the 1.5 T MR-Linac. METHODS: Patients with locally advanced rectal cancer (LARC) underwent standard neoadjuvant radiochemotherapy with 50.4 Gy in 28 fractions. T2-weighted MRI prior and after the treatment session were acquired to contour gross tumor volumes (GTVs) and organs at risk (OARs). The datasets were used to simulate four different boost strategies (all with 15 Gy/5 fractions in addition to 50.4 Gy): up-front boost (5 daily fractions in the first week of treatment) and an adaptive boost (one boost fraction per week). Both strategies were planned using standard and reduced PTV margins. Intra-fraction motion was assessed by pre- and post-treatment MRI-based contours. RESULTS: Five patients were included and a total of 44 MRI sets were evaluated. The median PTV volumes of the adaptive boost were significantly smaller than for the up-front boost (81.4 cm3 vs 44.4 cm3 for PTV with standard margins; 31.2 cm3 vs 15 cm3 for PTV with reduced margins; p = 0.031). With reduced margins the rectum was significantly better spared with an adaptive boost rather than with an up-front boost: V60Gy and V65Gy were 41.2% and 24.8% compared with 59% and 29.9%, respectively (p = 0.031). Median GTV intra-fractional motion was 2 mm (range 0-8 mm). CONCLUSIONS: The data suggest that the adaptive boost strategy exploiting tumor-shrinkage and reduced margin might result in better sparing of rectum and anal canal. Individual margin assessment, motion management and real-time adaptive radiotherapy appear attractive applications of the 1.5 T MR-Linac for further testing of individualized and safe dose escalation in patients with rectal cancer.

Dosimetric Predictors of Acute and Chronic Alopecia in Primary Brain Cancer Patients Treated With Volumetric Modulated Arc Therapy.

Purpose: To determine dose constraints that correlate with alopecia in patients treated with photon-based Volumetric Modulated Arc Therapy (VMAT) for primary brain tumors. Methods: During the treatment planning process, the scalp was drawn as a region of interest. Dose received by 0.1 cc (D0.1cc), mean dose (Dmean), absolute volumes receiving different doses (V16Gy, V20Gy, V25Gy, V30Gy, V35Gy, V40Gy, and V43Gy) were registered for the scalp. Alopecia was assessed according to Common Terminology Criteria for Adverse Events (CTCAE) v4.0. Receiver operating characteristics (ROC) curve analysis was used to identify parameters associated with hair-loss. Results: One-hundred and one patients were included in this observational study. At the end of radiotherapy (RT), 5 patients did not develop alopecia (Dmean scalp 3.1 Gy). The scalp of the patients with G1 (n = 11) and G2 (n = 85) alopecia received Dmean of 10.6 Gy and 11.8 Gy, respectively. At ROC analysis, V16Gy20Gy ≥ 5.2 cc were the strongest predictors of acute alopecia risk. Chronic hair-loss assessment was available for 74 patients: median time to recovery from G2 alopecia was 5, 9 months. The actuarial rate of hair regrowth was 98.1% at 18 months after the end of RT. At ROC analysis, V40Gy43Gy ≥2.2 cc were the strongest predictors of chronic G2-alopecia risk. V20Gy, V40Gy, and D0,1cc were shown to be independent variables according to correlation coefficient r. Conclusions: V20Gy and V40Gy were the strongest predictors for acute and chronic G2 hair-loss, respectively. The low-dose bath typical of VMAT corresponds to large areas of acute but transient alopecia. However, the steep dose gradient of VMAT allows to reduce the areas of the scalp that receive higher doses, minimizing the risk of permanent alopecia. The application of our dosimetric findings for the scalp may help in reducing the alopecia risk and also in estimating the probability of hair-loss during patient counseling before starting radiotherapy.

Stereotactic radiotherapy for prostate bed recurrence after prostatectomy, a multicentric series.

OBJECTIVE: To assess the safety and effectiveness of stereotactic salvage radiotherapy (SSRT) in RT-naïve patients affected by macroscopic prostate bed recurrence. PATIENTS AND METHODS: Consecutive patients treated for prostate bed macroscopic recurrence in three different Italian institutes were reviewed. Patients were treated with SSRT, with a total dose of 30-40 Gy in five fractions, the mean pre-SSRT PSA level was 2.3 ng/mL. Two different PSA thresholds were defined and biochemical recurrence-free survival (BCRFS) was reported, in order to better express outcome: BCRFS1 (a PSA level increase of >10% compared to the pre-SSRT value) and BCRFS2 (a PSA level increase of >0.2 ng/mL for patients with a PSA nadir of <0.2 ng/mL or two consecutive PSA level increases of >25% compared to nadir in patients with a PSA nadir of <0.2 ng/mL). RESULTS: In all, 90 patients were treated, with a mean (range) follow-up of 21.2 (2-64) months, and 17 of these patients (19%) had concomitant androgen-deprivation therapy (ADT) during SSRT. Complete biochemical response, defined as a PSA nadir of <0.2 ng/mL, was obtained in 39 of the 90 patients (43.3%). Considering BCRFS1, 25 patients (27.8%) had BCR, with an actuarial median BCRFS1 time of 36.4 months. For BCRFS2, BCR was reported in 32 patients (35.5%), with an actuarial median BCRFS2 time of 24.3 months. There was no Grade >2 toxicity. CONCLUSIONS: SSRT was found to yield significant biochemical control and allowed ADT delay despite adverse features.

Partial breast irradiation with the 1.5 T MR-Linac: First patient treatment and analysis of electron return and stream effects.

INTRODUCTION: External beam partial breast irradiation (PBI) provides equal oncological outcomes compared to whole breast irradiation when applied to patients with low risk tumours. Recently, linacs with an integrated magnetic resonance image-guidance system have become clinically available. Here we report the first-in-human PBI performed at the 1.5 T MR-Linac, with a focus on clinical feasibility and investigation of the air electron stream effect (ESE) and the electron return effect (ERE) in the presence of the 1.5 T magnetic field, which might influence the dose on the chin (out-of-field dose, due to the ESE), the skin and the lung/chest wall interface (in-field dose, ERE). METHODS: A 59 years old patient affected by a 15 mm unifocal grade 1 carcinoma not special type of the right breast staged pT1c pN0 cM0 was planned and treated at Unity 1.5 T MR-Linac. To investigate the ERE and the ESE, an MR-Linac treatment plan was simulated without considering the 1.5 T B field using a research version of Monaco (V. 5.19.03). In vivo dosimetry was performed using Gafchromic® EBT3 films placed on top and underneath a 1 cm bolus which was placed on the patient's chin. The plans with and without 1.5 T magnetic field were compared in terms of dose to the chin, to the skin and to the interface lung/chest wall. Finally, the dose on the chin measured with the in vivo dosimetry was compared with the dose calculated by Monaco. RESULTS: PBI using the 1.5 T MR-Linac was successfully performed with a 7 MV photon 7-beams IMRT step-and-shoot plan. The treatment was well tolerated, the patient developed a slight acute toxicity, i.e. breast skin erythema and breast oedema CTC V.4 grade 1. The plan with 1.5 T magnetic field documented a fractional dose of 0.17 Gy in the chin area (2.6 Gy in 15 fractions), which was reduced to 0.05 Gy (0.75 in 15 fractions) by the presence of 1 cm bolus. The simulated plan without magnetic field showed a dose reduced by 2.3 Gy in the chin area. With the in vivo dosimetry a fractional dose of, respectively, 0.12 Gy and 0.034 Gy on top and underneath the bolus were measured (1.8 and 0.51 Gy in 15 fractions). The plan with 1.5 T magnetic field showed a skin D2 of 40 Gy and a skin V35 of 40.2%, which were reduced to, respectively, 39.7 Gy and 24.9% in the simulation without magnetic field. At the interface lung/chest there were no differences in DVH statistics. CONCLUSION: PBI with the 1.5 T MR-Linac was performed for the first time. ESE is accurately calculated by the treatment planning system, can be effectively reduced with a 1 cm bolus and is comparable to dose of cone beam-CT based position verification. The additional dose caused by ERE is not associated with an increased risk of acute toxicity.

Patterns of Care and Survival in Elderly Patients With Locally Advanced Soft Tissue Sarcoma.

OBJECTIVES: The aim of this study was to analyze patterns of care in elderly soft tissue sarcoma (STS) patients and their impact on clinical outcome and treatment-related toxicity. MATERIALS AND METHODS: We retrospectively collected data of >65-year-old patients diagnosed with locally advanced STS between 1991 and 2017 in a single institution. RESULTS: The study included 111 patients: 105 (94.6%) patients underwent surgery, associated with preoperative (n=19, 17.1%) or postoperative radiotherapy (n=72, 64.8%). Anthracycline-based chemotherapy was prescribed in 41.4% of patients (n=46). Acute grade ≥3 postoperative radiotherapy-related radiation dermatitis and all grades of chemotherapy-induced neutropenia were significantly correlated to age >80 years (P=0.02) and >70 years (P=0.045), respectively. The mean follow-up was 4.1 years (range, 0.1 to 17.7). Three-year and 5-year local recurrence-free survival were 80.3% and 75.7%, respectively; neither treatment-related nor patient-related characteristics affected local recurrence. Three-year and 5-year distant relapse-free survival were 59.6% and 44.6%, respectively. On multivariate Cox regression, undifferentiated pleomorphic sarcoma histology and Charlson Comorbidity Index >7 were independent factors associated with distant relapse-free survival (P=0.026 and P=0.0001). Overall survival was 62% and 46.6% at 3 and 5 years, respectively. On multivariate Cox regression, surgery and Charlson Comorbidity Index <7 were independent factors associated with overall survival (P=0.006 and P=0.0001). CONCLUSIONS: In this study, elderly STS patients receiving a tailored treatment encompassing surgery, radiotherapy, and/or chemotherapy obtained an improved outcome, although caution is advised because of increased toxicity in relation to age. Comorbidities should be considered to offer the best treatment option to this frail patient population.

Efficacy and Tolerability of CyberKnife Stereotactic Robotic Radiotherapy for Primary or Secondary Orbital Lesions: A Single-Center Retrospective Experience.

INTRODUCTION: Orbital lesions are rare, but are likely to become symptomatic and can impact on patients' quality of life. Local control is often difficult to obtain, because of proximity to critical structures. CyberKnife stereotactic robotic radiotherapy could represent a viable treatment option. MATERIALS AND METHODS: Data on patients treated for intraorbital lesions from solid malignancies were retrospectively collected. All patients underwent treatment with CyberKnife system. We analyzed local control, response rate, symptoms control, progression-free survival and overall survival, acute and late toxicity. RESULTS: From January 2012 to May 2017, 20 treatments on 19 patients were performed, with dose ranging from 24 to 35 Gy in 1 to 5 fractions, prescribed at an average isodose line of 79.5% (range: 78-81). After a mean follow-up of 14.26 months (range: 0-58), overall response rate was 75%, with 2 and 4 patients presenting a partial and complete response, respectively. Mean time to best measured response was 15.16 months (range: 2-58). Thirteen patients were alive, with a local control rate of 79%. Mean time to local progression was 5 months (range: 3-7). Three patients reported improvement in symptoms after treatment. Mean planning target volume dose coverage was 97.2% (range: 93.5-99.7). Mean maximum dose (D max) to eye globe, optic nerve, optic chiasm, and lens was 2380.8 cGy (range: 290-3921), 1982.82 cGy (range: 777.3-2897.8), 713.14 cGy (range: 219.5-2273), and 867.9 cGy (range: 38-3118.5). Four patients presented acute toxicity. CONCLUSION: This current retrospective series demonstrated that CyberKnife robotic stereotactic radiotherapy is a feasible and tolerable approach for intraorbital lesions.

A matched cohort study of radio-chemotherapy versus radiotherapy alone in soft tissue sarcoma patients.

PURPOSE: Adjuvant radiotherapy is the standard postoperative treatment after conservative surgery in high risk soft tissue sarcoma. The role of adjuvant chemotherapy is still debated. Therefore, a matched cohort analysis was performed in high risk soft tissue patients to analyse differences in terms of clinical outcome and toxicity between patients treated with concomitant radio-chemotherapy (RTCT) and radiotherapy (RT) alone. MATERIALS AND METHODS: For each patient in RT group was selected a patient in the RTCT group matching for age, T stage and grading. Acute and late toxicity were recorded, overall survival, recurrence free survival and distant metastases free survival were analysed and compared between the two groups. RESULTS: Ninety patients were selected, half of patients underwent radio-chemotherapy and half received radiotherapy alone. During the treatment Grade 3 dermatitis was recorded in 15 (16.7%) patients, 6 (6.7%) patients associated chemotherapy and during follow up 12 (13.3%) patients developed grade 2 late fibrosis, 3 (3.3%) joint stiffness and 1 (1.1%) patient experienced a bone fracture. There were no differences in the rate of acute and late toxicity between RTCT and RT alone group. Nineteen (21.1%) patients developed local recurrence, overall 5-year local relapse free survival was 83%. There were no differences between the two groups. 29 patients developed distant metastases, 14 (15.6%) patients in the RTCT group and 15 (16.7%) patients in the RT group. The 5-year distant metastases free survival was 67%. Age > 65 years was the only independent factor affecting distant recurrence (HR = 5.7, 95% CI 2.7-11.9; p = 0.001). At the time of analysis 15 (16.7%) patients were dead, 6 (6.7%) patients in the RTCT group and 9 (10%) patients in the RT group. 5-years overall survival was: 88%. At multivariate analysis age > 65 years was an independent prognostic factor of overall survival (HR = 3.7, 95% CI 1.2-12.1, p = 0.037). CONCLUSIONS: Prospective randomized studies with large size population and with subgroup analysis for histological subtypes are necessary to clarify the role of adjuvant chemotherapy in soft tissue sarcoma patients. Tailored treatment has to be considered in elderly soft tissue patients to guarantee a better outcome in this high risk and fragile population.

Influence of age and subtype in outcome of operable liposarcoma.

AIM: Liposarcoma (LPS) is rare tumor deriving from adipocytes. LPS is classified into histological subtypes: well-differentiated (WDLPS), dedifferentiated (DDLPS), myxoid (MLPS) and pleomorphic (PLPS). A tailored approach taking into account the specificity of disease subtype and age at presentation could be helpful in delineating therapeutic management of liposarcoma. In this paper, we report a retrospective series of a single-institution cohort of patients with LPS, undergoing surgery and radiotherapy and/or chemotherapy. The aim of this study is to evaluate whether clinical characteristics, tumor- and treatment-related features affect clinical outcome in patients treated with curative intent for non-metastatic liposarcoma. METHODS: Data of patients with locally advanced, non-metastatic liposarcoma treated between 1990 and 2015 were retrospectively reviewed. Data about patient, tumor and treatment features were collected. Two patients subgroups were identified according to age (cutoff: age < 65 years or > 65 years). Statistical analysis was performed to assess correlation between the above-cited variables and local recurrence-free survival (DFS-LR), distant metastasis-free survival, overall survival (OS) and disease-specific survival (DSS); moreover, differences in clinical outcome between the two age groups were identified. RESULTS: Data of 186 patients were collected. At diagnosis, 27.4% of patients were 65 years or older. At a median follow-up of 8.6 years (range 0.1-27.3 years), Kaplan-Meier (KM) survival analysis showed that LR, DM, OS and DSS were 75.5%, 76.6%, 48.1% and 72.1%, respectively. KM analysis showed that age > 65, DDLPS and lower limb localization were related to LR (p = 0.001, p = 0.0001 and p = 0.0001, respectively). Association between LR, age and DDLPS persisted both at univariate (p = 0.003 and p = 0.0001, respectively) and multivariate Cox regression (CR) analysis (p = 0.024 and p = 0.002). Age, tumor depth and grading influenced distant recurrence, both at KM (p = 0.023, p = 0.026 and p = 0.016) and univariate CR (p = 0.026, p = 0.042 and p = 0.012). Age and grading were confirmed at multivariate analysis (p = 0.009 and p = 0.017). Patients with WDLPS and wide excision had significantly better OS (p = 0.001 and p = 0.03, respectively), while histological G3 and age > 65 were related with worse OS (p = 0.008 and p = 0.0001, respectively). Age, DDLPS and grade were related to OS at univariate (p = 0.0001, p = 0.0001 and p = 0.03, respectively) and multivariate CR analysis (p = 0.031, p = 0.0001 and p = 0.001, respectively). However, analyzing the specific causes of death, female died less often for tumor-related causes, with a DSS of 91.0% compared to 57.4% of male counterpart (p = 0.005). At Kaplan-Meier analysis, postoperative radiotherapy resulted in a statistically significant better disease-specific survival than postoperative radiotherapy (82.9% vs. 46.2%, p = 0.045). High grade correlated with poorer disease-specific survival (59.3%) than intermediate and low grade (73.4% and 91.6%, respectively) (p = 0.008). Association between DSS, sex and grade persisted both at univariate (p = 0.008 and p = 0.022, respectively) and multivariate Cox regression (CR) analysis (p = 0.014 and p = 0.038). Histotype-driven schedules of treatment should be developed to take into account biological heterogeneity of this disease. Further studies are needed to stratify patients subgroup and develop tailored treatment strategies (i.e., altered fractionations and different chemotherapy regimens in aggressive subtypes), in particular more prospective trials are needed to develop treatment guidelines in elderly STS, taking into account the frailty and the peculiarity of this subgroup.

Management of severe bio-radiation dermatitis induced by radiotherapy and cetuximab in patients with head and neck cancer: emphasizing the role of calcium alginate dressings.

PURPOSE: Severe bio-radiation dermatitis may develop in patients treated with concurrent radiotherapy and cetuximab for head and neck squamous cell carcinoma. The aim of our work was to report on the impact of a grade-specific management approach on treatment tolerability. METHODS: Concomitant radiotherapy and cetuximab was prescribed for patients deemed ineligible for cisplatin-based chemoradiation. Since 2014, an advanced wound care nursing team was established in our clinic to implement a standardized policy for skin toxicity. A central role of calcium alginate dressings was defined in our management algorithm. The correlation between patient, disease, and treatment features with severe bio-radiation dermatitis and treatment tolerability was evaluated. RESULTS: Between 2007 and 2018, 51 patients were treated at our center with radiotherapy and cetuximab. The incidence of G3/G4 bio-radiation dermatitis was 43.1%. Comparing two consecutive cohorts of 26 and 25 patients treated before and after January 2014, respectively, the adoption of a grade-specific dermatitis management allowed to improve treatment tolerability. A mean radiation treatment interruption of 8.42 days (SD, 6.73; 95% CI 5.7-11.1) was reduced to 0.86 days (SD, 2.66; 95% CI - 0.28-2.02) in the more recent group (p < 0.0001). Mean relative dose intensity of cetuximab was also significantly higher (86.3% vs 74.5%, p = 0.0226). CONCLUSIONS: Routine involvement of an advanced wound care management team and early consideration for calcium alginate dressings in case of moist desquamation should be warranted to ensure high compliance to radiotherapy and cetuximab in patients with head and neck cancer.

Elderly patients affected by head and neck squamous cell carcinoma unfit for standard curative treatment: Is de-intensified, hypofractionated radiotherapy a feasible strategy?

OBJECTIVES: The aim of our work was to report on the clinical outcome of a moderately hyprofractionated radiotherapy regimen in elderly patients affected by head and neck squamous cell carcinoma (HNSCC). MATERIAL AND METHODS: HNSCC aged ≥65 deemed unsuitable for curatively-intended concurrent chemo-radiotherapy or high-dose radiotherapy by clinical judgement were further evaluated with the Geriatric 8 (G8) questionnaire and Charlson comorbidity index (CCI). In case of a G8 score ≤14, a de-intensified radiation schedule of 40 Gy delivered in 16 fractions was prescribed. RESULTS: Thirty-six patients were treated between 2011 and 2016. The median age of the cohort was 77.5 (range: 65-91 years) with a combined ECOG PS of 2-3 in 77.8% and CCI of ≥8 in 25% patients, respectively. At a median follow-up of 13 months (range 2-62 months), the 6-month and 1-year rates of loco-regional control and progression-free survival were 42%, 28% and 36% and 20%, respectively. At univariate analysis, log-rank test showed that age >75 years (p=0.036), worse PS (ECOG≥2; p=0.027), lower G8 score (<9; p=0.027) and PTV volume greater than 200 cc (p=0.038) had a significant correlation with PFS. The negative impact of the PTV volume on PFS was the only parameter confirmed in the multivariate analysis (HR 2.68; 95% CI: 1.24-5.81, p=0.013). No grade 4-5 toxicity was observed, while 13/36 patients (36%) had G3 acute side effects. CONCLUSION: The hypofractionated radiation schedule evaluated provides clinical benefit with low toxicity in frail, elderly patients affected by locally advanced HNSCC.

Impact of hormonal status on outcome of ductal carcinoma in situ treated with breast-conserving surgery plus radiotherapy: Long-term experience from two large-institutional series.

BACKGROUND: Ductal carcinoma in situ (DCIS) is a heterogeneous disease, for which the best adjuvant treatment is still uncertain. Many attempts of risk-groups stratification have been made over time, developing prognostic scores to predict risk of local recurrence (LR) on the basis of features such as age, final surgical margins (FSM) status, grade, and tumor size. The aim of our analysis was to evaluate the patterns of recurrence from a two large-institutional retrospective series. PATIENTS AND METHODS: We collected data on 457 patients treated with BCS and adjuvant RT between 1990 and 2012. Final analysis was performed on 278 patients, due to missing data about hormonal status (HS). Patients were treated at the Radiation Oncology Unit of the University of Florence (n = 195), and S. Maria Annunziata Hospital (n = 83) (Florence, Italy). RESULTS: At a median follow up time of 10.8 years (range 3-25), we observed 20 LR (7.2%). The 5-year and 10-year LR rates were 4.9% and 10.2%, respectively. At Cox regression univariate analysis, estrogen receptor (ER) positive status (p = 0.001), HS positive (p = 0.003), and FSM <1 mm (p = 0.0001) significantly impacted on LR. At Cox regression multivariate analysis positive ER status maintained a protective role (p = 0.003), and FSM status <1 mm its negative impact (p = 0.0001) on LR rate. CONCLUSIONS: Our experience confirmed the wide heterogeneity of DCIS. Inadequate FSM and negative ER status negatively influenced LR rates. Tumor biology should be integrated in adjuvant treatment decision-making process.