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Abstract Objective To analyze the pattern of failure in relation to pre-treatment [18F] FDG-PET/CT uptake in head and neck squamous cell carcinoma (HNSCC) patients treated with definitive radio-chemotherapy (RT-CHT). Methods and materials From 2012 to 2016, 87 HNSCC patients treated with definitive RT-CHT, with intensity modulated radiation therapy with simultaneous integrated boost, underwent pre-treatment [18F] FDG-PET/CT (PETpre), and MRI/CT for radiotherapy (RT) planning purposes. Patients with local recurrence, received [18F] FDG-PET/CT, (PETrec) at the time of the discovery of recurrence. In these patients, the metabolic target volume (MTV), MTVpre and MTVrec were segmented on PET images by means of an adaptive thresholding algorithm. The overlapping volume between MTVpre and MTVrec (MTVpre&rec) was generated and the dose coverage of MTVrec and MTVpre&rec was checked on the planning CT using the D99 and D95 dose metrics. The recurrent volume was defined as: ‘‘In-Field (IF)’’, “Marginal recurrence” or ‘‘Out-of-Field (OF)’’ if D95 was respectively equal or higher than 95%, D95 was between 95 and 20% or the D95 was less than 20% of prescribed dose. Results We found 10/87 patients (11.5%) who had recurrence at primary site. Mean MTVpre was 12.2 cc (4.6–28.9 cc), while the mean MTVrec was 4.3 cc (1.1–12.7 cc). Two recurrences resulted 100% inside MTVpre, 4 recurrences were mostly inside (61–91%) and 4 recurrences were marginal to MTVpre (1–33%). At dosimetric analysis, five recurrences (50%) were IF, 4 (40%) marginal and one (10%) OF. The mean D99 of the overlapping volumes MTVpre&rec was 68.1 Gy (66.5–69.2 Gy), considering a prescription dose of 70 Gy to the planning target volume (PTV). Conclusion Our study shows that the recurrence may originate from the volume with the highest FDG-signal. Tumor relapse in the high-dose volume support the hypothesis that an intensification of the dose on these volumes could be further assessed to prevent local relapse.

Background: Image guided radiotherapy (IGRT) is an essential pre-requisite for delivering high precision radiotherapy. We compared daily variation detected by two non-ionizing imaging modalities (surface imaging and trans-abdominal ultrasound, US) to verify prostate patient setup and internal organ variations., Methods: Forty patients with organ confined prostate cancer and candidates to curative radiotherapy were enrolled in this prospective study. At each treatment session, after laser alignment, all patients received imaging by a 3D-surface and a 3D-US system. The shifts along the three directions (anterior-posterior AP, cranial-caudal CC, and later-lateral LL) were measured in terms of systematic and random errors. Then, we performed statistical analysis on the differences and the possible correlations between the two modalities., Results: For both IGRT modalities, surface imaging and US, 1318 acquisitions were collected. According with Shapiro Wilk test, the positioning error distributions were not Gaussian for both modalities. The differences between the systematic errors detected by the two modalities were statistically significant only in LL direction (p < 0.05), while the differences between the random errors were not statistically significant in any directions. The 95% confidence interval of the residual errors obtained by subtracting the random errors detected with surface images to those detected with US was included in the range from -7 mm to 7 mm corresponding to the minimum PTV margin adopted in AP direction in our clinical routine., Conclusions: From our data, it emerges that setup misalignments measured by surface imaging can be predictive of US displacements after the adjustment for systematic errors. Moreover, surface imaging can detect setup errors predictive of registration errors measured by US. This data suggest that the two IGRT modalities could be considered as complementary to each other and could represent a daily "low-cost" and non-invasive IGRT modality in prostate cancer patients.

Introduction: Aggressive cancer treatment is a challenge in elderly patients. The present study aims to assess tolerance in terms of acute toxicity and compliance of concurrent chemo-radiotherapy (cCRT) in a series of patients aged ≥70 years., Materials and Methods: Clinical records of patients aged ≥70 years who underwent cCRT between January 2005 and December 2013 were reviewed. Concurrent CRT had curative intent in 134 patients (97.8 %) and palliative intent in 3 patients (2.2 %). Chemotherapy (CT) drugs and schedule were selected according to tumor histology. Radiotherapy median dose was 45.0 Gy (range 11-70 Gy) for curative purposes and 54 Gy (range 40-56 Gy) for palliative purposes. Incidence of acute toxicity and compliance to cCRT were analyzed and correlated with age, Karnofsky Performance Status (KPS), and Charlson Comorbidity Index (CCI)., Results: Overall, 137 patients, 82 males (60 %) and 55 females (40 %), median age 74 years (range 70-90 years) were analyzed. Concurrent CRT schedule was completed by 132 patients (96.4 %). Thirty-one of these patients (23.5 %) temporarily interrupted treatment. Hematological toxicity with grade ≥1 was observed in 25 patients (18.2 %), gastrointestinal toxicity in 55 (40.1 %), and genitourinary in 13 (9.5 %). Mucositis with grade ≥1 was recorded in 19 patients (13.9 %). No statistical significant correlation between KPS, CCI, and toxicity was found. A correlation trend between mucositis and patient age (p = 0.05) was observed., Conclusion: Concurrent CRT for elderly was feasible and quite well tolerated. Great attention in prescribing CT dose should be paid to limit acute toxicity.