[18F]Fluorocholine PET/CT-guided stereotactic body radiotherapy in patients with recurrent oligometastatic prostate cancer.

BACKGROUND: In the last years, functional imaging has given a significant contribution to the clinical decision-making of biochemically relapsed prostate cancer (PCa). Hereby, we present a prospective study aiming to validate the role of [18F]Fluoro-Methyl Choline ([18F]FMCH) PET/CT in the selection of PCa patients suitable for stereotactic body radiotherapy (SBRT). METHODS: Patients with biochemical recurrence limited up to three lesions revealed by [18F]FMCH PET/CT were enrolled in the present study and treated with SBRT on all active lesions. Systemic therapy-free survival since the [18F]FMCH PET/CT was considered as the primary endpoint. RESULTS: Forty-six patients were evaluated, and a total of 67 lesions were treated. After a median follow-up of 28.9 months, systemic therapy was started in 30 patients (65.2%) and median systemic therapy-free survival was 39.1 months (95% CI 6.5-68.6); 6, 12, and 24-month ratios were 93.5%, 73.9%, and 63.1%, respectively. At univariate Cox regression analysis, Delta PSA demonstrated an impact on systemic therapy-free survival (p < 0.001). CONCLUSIONS: Based on our findings, [18F]FMCH PET/CT can identify oligometastatic prostate cancer patients suitable for SBRT, resulting in a systemic therapy-free survival of 39.1 months.

Magnetic resonance imaging (MRI) compared with computed tomography (CT) for interobserver agreement of gross tumor volume delineation in pancreatic cancer: a multi-institutional contouring study on behalf of the AIRO group for gastrointestinal cancers.

BACKGROUND: Due to the high soft tissue resolution, magnetic resonance imaging (MRI) could improve the accuracy of pancreatic tumor delineation in radiation treatment planning. A multi-institutional study was proposed to evaluate the impact of MRI on inter-observer agreement in gross tumor volume (GTV) and duodenum delineation for pancreatic cancer compared with computer tomography (CT). MATERIAL AND METHODS: Two clinical cases of borderline resectable (Case 1) and unresectable (Case 2) pancreatic cancer were selected. In two sequential steps, diagnostic contrast-enhanced CT scan and MRI sequences were sent to the participating centers. CT-GTVs were contoured while blinded to MRI data sets. DICE index was used to evaluate the spatial overlap accuracy. RESULTS: Thirty-one radiation oncologists from different Institutions submitted the delineated volumes. CT- and MRI-GTV mean volumes were 21.6 ± 9.0 cm3 and 17.2 ± 6.0 cm3, respectively for Case 1, and 31.3 ± 15.6 cm3 and 33.2 ± 20.2 cm3, respectively for Case 2. Resulting MRI-GTV mean volume was significantly smaller than CT-GTV in the borderline resectable case (p < .05). A substantial agreement was shown by the median DICE index for CT- and MRI-GTV resulting as 0.74 (IQR: 0.67-0.75) and 0.61 (IQR: 0.57-0.67) for Case 1; a moderate agreement was instead reported for Case 2: 0.59 (IQR:0.52-0.66) and 0.53 (IQR:0.42-0.62) for CT- and MRI-GTV, respectively. CONCLUSION: Diagnostic MRI resulted in smaller GTV in borderline resectable case with a substantial agreement between observers, and was comparable to CT scan in interobserver variability, in both cases. The greater variability in the unresectable case underlines the critical issues related to the outlining when vascular structures are more involved. The integration of MRI with contrast-enhancement CT, thanks to its high definition of tumor relationship with neighboring vessels, could offer a greater accuracy of target delineation.

Adjuvant chemotherapy after preoperative (chemo)radiotherapy and surgery for patients with rectal cancer: a systematic review and meta-analysis of individual patient data.

BACKGROUND: The role of adjuvant chemotherapy for patients with rectal cancer after preoperative (chemo)radiotherapy and surgery is uncertain. We did a meta-analysis of individual patient data to compare adjuvant chemotherapy with observation for patients with rectal cancer. METHODS: We searched PubMed, Medline, Embase, Web of Science, the Cochrane Library, CENTRAL, and conference abstracts to identify European randomised, controlled, phase 3 trials comparing observation with adjuvant chemotherapy after preoperative (chemo)radiotherapy and surgery for patients with non-metastatic rectal cancer. The primary endpoint of interest was overall survival. FINDINGS: We analysed data from four eligible trials, including data from 1196 patients with (y)pTNM stage II or III disease, who had an R0 resection, had a low anterior resection or an abdominoperineal resection, and had a tumour located within 15 cm of the anal verge. We found no significant differences in overall survival between patients who received adjuvant chemotherapy and those who underwent observation (hazard ratio [HR] 0.97, 95% CI 0.81-1.17; p=0.775); there were no significant differences in overall survival in subgroup analyses. Overall, adjuvant chemotherapy did not significantly improve disease-free survival (HR 0.91, 95% CI 0.77-1.07; p=0.230) or distant recurrences (0.94, 0.78-1.14; p=0.523) compared with observation. However, in subgroup analyses, patients with a tumour 10-15 cm from the anal verge had improved disease-free survival (0.59, 0.40-0.85; p=0.005, p(interaction)=0.107) and fewer distant recurrences (0.61, 0.40-0.94; p=0.025, p(interaction)=0.126) when treated with adjuvant chemotherapy compared with patients undergoing observation. INTERPRETATION: Overall, adjuvant fluorouracil-based chemotherapy did not improve overall survival, disease-free survival, or distant recurrences. However, adjuvant chemotherapy might benefit patients with a tumour 10-15 cm from the anal verge in terms of disease-free survival and distant recurrence. Further studies of preoperative and postoperative treatment for this subgroup of patients are warranted. FUNDING: None.

Total neoadjuvant treatment and organ preservation strategies in the management of localized rectal cancer: A narrative review and evidence-based algorithm.

The multimodal approach with total mesorectal excision preceded by neoadjuvant (chemo)radiotherapy represented the mainstay treatment for locally advanced rectal cancer (LARC) for a long time. However, the benefit of adjuvant chemotherapy in terms of distant relapse reduction is limited. Recently, chemotherapy regimens administered before surgery and incorporated with (chemo)radiotherapy in total neoadjuvant treatment protocols have been established as new options in the management of LARC. Meanwhile, patients with clinical complete response to neoadjuvant treatment can benefit from organ preservation strategies, aimed at sparing surgery and long-term post-operative morbidities, while preserving an adequate disease control. However, the introduction of a non-operative management in clinical practice is a matter of debate with some concerns regarding the risk of local recurrence and long-term outcomes. In this review, we discuss how these recent advances are reshaping the multimodal management of localized rectal cancer and propose an algorithm to place them in the clinical practice.

ShorTrip Trial: A Prospective, Multicentric Phase II Single-Arm Trial of Short-Course Radiotherapy Followed by Intensified Consolidation Chemotherapy With the Triplet FOLFOXIRI as Total Neoadjuvant Therapy in Locally Advanced Rectal Cancer.

BACKGROUND: In patients with locally advanced rectal cancer (LARC) treated with preoperative (chemo) radiotherapy and surgery, adjuvant chemotherapy is poorly feasible and its benefit is questionable. In the last years, several total neoadjuvant treatment (TNT) strategies, moving the adjuvant chemotherapy to the neoadjuvant setting, have been investigated with the aim of improving compliance to systemic chemotherapy, treating micrometastases earlier and then reducing distant recurrence. PATIENTS AND METHODS: ShorTrip (NTC05253846) is a prospective, multicentre, single-arm phase II trial where 63 patients with LARC will be treated with short-course radiotherapy followed by intensified consolidation chemotherapy with FOLFOXIRI regimen and surgery. Primary endpoint is pCR. Among the first 11 patients who started consolidation chemotherapy, a preliminary safety analysis showed a high rate of grade 3 to 4 neutropenia (N = 7, 64%) during the first cycle of FOLFOXIRI. Therefore, the protocol has been emended with the recommendation to omit irinotecan during the first cycle of consolidation chemotherapy. After amendment, in a subsequent safety analysis focused on the first 9 patients treated with FOLFOX as first cycle and then with FOLFOXIRI, grade 3 to 4 neutropenia was reported in only one case during the second cycle. AIM OF THE STUDY: The aim of this study is to assess the safety and activity of a TNT strategy including SCRT, intensified consolidation treatment with FOLFOXIRI and delayed surgery. After protocol amendment, the treatment seems feasible without safety concern. Results are expected at the end of 2024.

Radiomics of Patients with Locally Advanced Rectal Cancer: Effect of Preprocessing on Features Estimation from Computed Tomography Imaging.

The purpose of this study was to investigate the effect of image preprocessing on radiomic features estimation from computed tomography (CT) imaging of locally advanced rectal cancer (LARC). CT images of 20 patients with LARC were used to estimate 105 radiomic features of 7 classes (shape, first-order, GLCM, GLDM, GLRLM, GLSZM, and NGTDM). Radiomic features were estimated for 6 different isotropic resampling voxel sizes, using 10 interpolation algorithms (at fixed bin width) and 6 different bin widths (at fixed interpolation algorithm). The intraclass correlation coefficient (ICC) and the coefficient of variation (CV) were calculated to assess the variability in radiomic features estimation due to preprocessing. A repeated measures correlation analysis was performed to assess any linear correlation between radiomic feature estimate and resampling voxel size or bin width. Reproducibility of radiomic feature estimate, when assessed through ICC analysis, was nominally excellent (ICC > 0.9) for shape features, good (0.75 < ICC ≤ 0.9) or moderate (0.5 < ICC ≤ 0.75) for first-order features, and moderate or poor (0 ≤ ICC ≤ 0.5) for textural features. A number of radiomic features characterized by good or excellent reproducibility in terms of ICC showed however median CV values greater than 15%. For most textural features, a significant (p < 0.05) correlation between their estimate and resampling voxel size or bin width was found. In CT imaging of patients with LARC, the estimate of textural features, as well as of first-order features to a lesser extent, is appreciably biased by preprocessing. Accordingly, this should be taken into account when planning clinical or research studies, as well as when comparing results from different studies and performing multicenter studies.

Early Versus Late Postoperative Radiotherapy in Patients With Prostate Cancer: Results of a Single-centre Retrospective Study.

BACKGROUND/AIM: A much-debated topic relating to patients at risk of local prostate cancer recurrence, but with post-operative leveIs of prostate-specific antigen (PSA) lower than 0.2 ng/ml, concerns the best timing of postoperative radiotherapy (RT), adjuvant or salvage? The present monocentric, retrospective study aimed to investigate the best PSA value at which to plan salvage RT for patients with recurrent prostate cancer. PATIENTS AND METHODS: From January 2011 to December 2019, 158 patients were treated with adjuvant RT at Pisa University Hospital, whilst 91 patients underwent salvage RT. We grouped the patients treated with salvage RT using their PSA values at the time of salvage RT: PSA >0.5 ng/ml, PSA between 0 and 0.5 ng/ml, and PSA ≤0.2 ng/ml. The median follow-up was 63 months. Biochemical recurrence-free survival (BFS) measured from surgery was the primary endpoint. RESULTS: Salvage RT led to shorter BFS compared to adjuvant RT considering the whole cohort of patients, with a hazard ratio of 3.195 (95% confidence interval=1.534-6.655, p=0.002). However, analysing only the group of patients with PSA ≤0.2 ng/ml at the time of salvage RT, salvage RT led to BFS similar to that achieved with adjuvant RT (p=0.35). CONCLUSION: Our results suggest that when scheduled for patients with a PSA ≤0.2 ng/ml, salvage RT results in equivalent biochemical control to that with adjuvant RT.

Bayesian network structure for predicting local tumor recurrence in rectal cancer patients treated with neoadjuvant chemoradiation followed by surgery.

Background and Purpose: Tumor recurrence, a characteristic of malignant tumors, is the biggest concern for rectal cancer survivors. The epidemiology of the disease calls for a pressing need to improve healthcare quality and patient outcomes. Prediction models such as Bayesian networks, which can probabilistically reason under uncertainty, could assist caregivers with patient management. However, some concerns are associated with the standard approaches to developing these structures in medicine. Therefore, this study aims to compare Bayesian network structures that stem from these two techniques. Patients and Methods: A retrospective analysis was performed on 6754 locally advanced rectal cancer (LARC) patients enrolled in 14 international clinical trials. Local tumor recurrence at 2, 3, and 5-years was defined as the endpoints of interest. Five rectal cancer treating physicians from three countries elicited the expert structure. The algorithmic structure was inferred from the data with the hill-climbing algorithm. Structural performance was assessed with calibration plots and area under the curve values. Results: The area under the curve for the expert structure on the training and validation data was above 0.9 and 0.8, respectively, for all the time points. However, the algorithmic structure had superior predictive performance over the expert structure for all time points of interest. Conclusion: We have developed and internally validated a Bayesian networks structure from experts' opinions, which can predict the risk of a LARC patient developing a tumor recurrence at 2, 3, and 5 years. Our result shows that the algorithmic-based structures are more performant and less interpretable than expert-based structures.

Adjuvant Radiotherapy in Patients With Pancreatic Adenocarcinoma. Is It Still Appealing in Clinical Trials? A Meta-analysis and Review of the Literature.

AIM: Pancreatic adenocarcinoma is a life-threatening disease with a rising frequency and the fourth leading cause of cancer death. This review aimed to assess the impact of postoperative radiotherapy through a meta-analysis of prospective randomized studies. MATERIALS AND METHODS: Six studies met the inclusion criteria and were analyzed to calculate the cumulative risk of death (hazard ratio) in patients affected by pancreatic cancer treated with or without radiotherapy. Higgins' index was used to determine heterogeneity in between-study variability and, subsequently, the random-effects model was applied according to DerSimonian and Laird. RESULTS: Eight hundred and thirty-seven patients were analyzed (418 in the control arm and 419 in the treatment one), the hazard ratio for death after randomization was 0.92 (p=0.560, 95% confidence interval=0.70-1.22). When scrutinizing these studies, only one out of six showed a statistically significant benefit due to the addition of radiotherapy in the postoperative setting. CONCLUSION: We conclude that the use of adjuvant radiotherapy is not beneficial in treating all patients affected by pancreatic cancer but only for a subset of cases with potential residual local disease.

Definition of Local Recurrence Site in Resected Pancreatic Adenocarcinoma: A Multicenter Study (DOLORES-1).

The study aimed to generate a local failure (LF) risk map in resected pancreatic cancer (PC) and validate the results of previous studies, proposing new guidelines for PC postoperative radiotherapy clinical target volume (CTV) delineation. Follow-up computer tomography (CT) of resected PC was retrospectively reviewed by two radiologists identifying LFs and plotting them on a representative patient CT scan. The percentages of LF points randomly extracted based on CTV following the RTOG guidelines and based on the LF database were 70% and 30%, respectively. According to the Kernel density estimation, an LF 3D distribution map was generated and compared with the results of previous studies using a Dice index. Among the 64 resected patients, 59.4% underwent adjuvant treatment. LFs closer to the root of the celiac axis (CA) or the superior mesenteric artery (SMA) were reported in 32.8% and 67.2% cases, respectively. The mean (± standard deviation) distances of LF points to CA and SMA were 21.5 ± 17.9 mm and 21.6 ± 12.1 mm, respectively. The Dice values comparing our iso-level risk maps corresponding to 80% and 90% of the LF probabilistic density and the CTVs-80 and CTVs-90 of previous publications were 0.45-0.53 and 0.58-0.60, respectively. According to the Kernel density approach, a validated LF map was proposed, modeling a new adjuvant CTV based on a PC pattern of failure.

Total neoadjuvant approach with FOLFOXIRI plus bevacizumab followed by chemoradiotherapy plus bevacizumab in locally advanced rectal cancer: the TRUST trial.

BACKGROUND: Neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC) does not achieve effective control of distant metastases. Induction chemotherapy is a promising strategy, and bevacizumab (BV) could improve the results of CRT. 5-Fluorouracil, oxaliplatin and irinotecan (FOLFOXIRI) plus BV is a treatment option in metastatic colorectal cancer. We evaluate feasibility and efficacy of neoadjuvant treatment comprising induction FOLFOXIRI plus BV followed by CRT with fluoropyrimidines plus BV. METHODS: In this phase II single-arm trial, patients node-positive or clinical T4 or high-risk T3 LARC underwent 6 cycles of induction FOLFOXIRI plus BV, followed by CRT (50.4 Gy plus concomitant capecitabine) and BV (5 mg/kg on days 1, 15 and 28). Surgery was planned 8 weeks after completion of CRT. Primary end-point was 2-year disease-free survival (DFS). RESULTS: We enrolled 49 patients: All but one (withdrewing consent after enrolment) were included in the per-protocol analyses. The study met its primary end-point: 36 patients were free of recurrence at 2 years (2-y DFS: 80.45%, 95% confidence interval [CI]: 78.79-82.10). Forty-four patients underwent surgery; pathologic complete response rate was 36.4%. Forty-six patients completed induction: neutropenia (41.6%) and diarrhoea (12.5%) were main G3/4 toxicities. Forty-five patients received CRT, but the protocol was amended and the capecitabine schedule during CRT was slightly modified after 13 patients due to the incidence of G3 hand-foot syndrome and proctitis (23.1%). After amendment, no severe events during CRT were reported. CONCLUSIONS: FOLFOXIRI plus BV followed by CRT plus BV is feasible and active. Results in terms of DFS suggest that this strategy may improve distant disease control in LARC.

Image-guided Stereotactic Body Radiotherapy in Metastatic Prostate Cancer.

BACKGROUND/AIM: In the last years, the use of Image Guided Stereotactic Radiotherapy (IG-SBRT) in patients with metastatic prostate cancer has increased. In this study, we aimed to assess the role of IG-SBRT in terms of local control and safety in patients with metastatic prostate cancer. MATERIALS AND METHODS: Primary and secondary endpoints of this prospective observational study were local control and safety related to IG-SBRT. All lesions were treated with 24 Gy as a single fraction or 27 Gy in 3 fractions. After SBRT, Systemic therapies were administered only after the occurrence of more than three synchronous active lesions in oligometastatic patients (patients with less than 4 active synchronous lesions) or new lesions occurrence in patients with more than 3 synchronous lesions. RESULTS: From April 2011 to June 2017, 78 metastatic lesions (32 bone and 46 node) from 51 patients with prostate cancer were treated. After a median follow-up of 18.5 months (range=3-103 months), only 2 lesions (4%) relapsed inside the radiation field. All local recurrences were located on the bone. Estimated 12 and 24 months local control ratios were 98.7 and 97.4%, respectively. Except for one case, toxicity greater than G2 was not recorded. CONCLUSION: IG-SBRT is safe and can be considered as a valid therapy in patients with metastatic prostate cancer requiring a long-lasting metastases control.

Adjuvant chemoradiotherapy (gemcitabine-based) in pancreatic adenocarcinoma: the Pisa University experience.

INTRODUCTION: The role of adjuvant chemoradiotherapy in patients with pancreatic adenocarcinoma (PA) is controversial. In this study we aimed to assess the feasibility, disease-free survival (DFS) and overall survival (OS) of adjuvant chemoradiotherapy (gemcitabine based) in patients with resected PA and their correlation with prognostic factors. METHODS: 122 resected patients (stage ≥IIa) treated between February 1999 and December 2013 were analyzed. Two cycles of gemcitabine (1,000 mg/m2 on days 1, 8 and 15 every 28 days) were administered before concomitant radiotherapy (45 Gy/25 fractions) and chemotherapy (gemcitabine 300 mg/m2 weekly). RESULTS: Median follow-up was 22.7 months (range 4-109). Gastrointestinal toxicity (G3), neutropenia (G3-G4) and cardiac toxicity (G2-G3) were observed in 2.4%, 10.6% and 1.6% of patients, respectively. OS at 12, 24 and 60 months was 79%, 55% and 31%, respectively (median 25 months). Two-year OS in patients with postoperative Karnofsky performance status (KPS) ≤70 and ≥80 was 37.1% and 62.3%, respectively (p<0.0001). OS was better in the group of patients with a postoperative CA 19-9 level ≤100 U/mL (p = 0.014). Median DFS was 17 months. CONCLUSIONS: The combination of concomitant gemcitabine and radiotherapy in patients with radically resected PA was well tolerated and associated with a low incidence of local recurrences. Five-year OS was significantly influenced by postoperative KPS and CA 19-9 values.

Natural history of graves' orbitopathy after treatment.

Intravenous glucocorticoids are used for Graves' orbitopathy, alone or associated with/followed by additional treatments (orbital radiotherapy, orbital decompression, palpebral or eye surgery). However, the relation between associated/additional treatments and other variables with Graves' orbitopathy outcome following intravenous glucocorticoids is not clear. Thus, the present study was conducted to investigate retrospectively the impact of associated/additional treatments and other variables on Graves' orbitopathy outcome after intravenous glucocorticoids. We evaluated 226 untreated Graves' orbitopathy patients. Following first observation, patients were given intravenous glucocorticoids and re-examined after a median of 46.5 months. The end-points were the relation between Graves' orbitopathy outcome, outcome of NOSPECS score and of the single Graves' orbitopathy features with several variables, including associated/additional treatments. All Graves' orbitopathy features improved significantly after treatment. Overall, Graves' orbitopathy improved in ~60 % of patients (responders), whereas it was stable or worsened in ~40 % of patients (non-responders). Time between first and last observation and clinical activity score at first observation correlated significantly with Graves' orbitopathy outcome. The outcomes of NOSPECS, eyelid aperture, clinical activity score and diplopia correlated with time between the first and last observation. The NOSPECS outcome correlated with gender. The outcomes of proptosis, eyelid aperture and visual acuity correlated with orbital decompression. The outcome of diplopia correlated with orbital radiotherapy. Taking into account the limitations of retrospective investigations, our findings confirm that time (i.e. the natural history of Graves' orbitopathy) is a key factor in determining the long-term outcome of Graves' orbitopathy, radiotherapy is effective for diplopia, and orbital decompression is followed by an amelioration of several Graves' orbitopathy features.

Stereotactic Body Radiotherapy in Patients with Lung Oligometastases from Colorectal Cancer.

AIM: To assess the role of stereotactic body radiotherapy (SBRT) in pulmonary metastases from colorectal cancer (CRC). PATIENTS AND METHODS: Thirty-three consecutive patients with pulmonary metastases from CRC who received SBRT were included in the analysis. The primary endpoints were local and systemic progression-free survival, a secondary endpoint was the safety profile of SBRT. RESULTS: A total of 56 lesions were treated with SBRT. A single nodule was treated in 15 patients, two in 13 and three in five. The radiotherapy dose and the adopted fractionations were 24-27 Gy as a single fraction for 40 lesions and 27-42 Gy in three fractions (2-3 times a week) for the other 16 lesions. After a median follow-up of 22.8 months (range=1.3-45.7 months), the median progression-free survival of the irradiated sites was 13.4 months. CONCLUSION: SBRT can be considered as local therapy in patients with lung metastases from CRC.

Time to surgery and pathologic complete response after neoadjuvant chemoradiation in rectal cancer: A population study on 2094 patients.

BACKGROUND: To retrospectively evaluate the difference in terms of pathologic complete response (pCR) according to time elapsed between chemoradiation (CRT) and total mesorectal excision (TME) on a large unselected real-life dataset of locally advanced rectal cancer (LARC) patients. METHODS: A multicentre retrospective cohort study of LARC patients from 21 Italian Radiotherapy Institutions was performed. Patients were stratified into 3 different time intervals from CRT. The 1st group included 300 patients who underwent TME within 6 weeks, the 2nd 1598 patients (TME within 7-12 weeks) and the 3rd 196 patients (TME within 13 or more weeks after CRT), respectively. RESULTS: Data on 2094 LARC patients treated between 1997 and 2016 were considered suitable for analysis. Overall, 578 patients had stage II while 1516 had stage III histological proven invasive rectal adenocarcinoma. A CRT schedule of one agent (N = 1585) or 2-drugs (N = 509) was administered. Overall, pCR was 22.3% (N = 468 patients). The proportion of patients achieving pCR with respect to time interval was, as follows: 12.6% (1st group), 23% (2nd group) and 31.1% (3rd group) (p < 0.001), respectively. The pCR relative risk comparison of 2nd to 1st group was 1.8, while 3rd to 2nd group was 1.3. Moreover, between the 3rd and 1st group, a pCR relative risk of 2.4 (p < 0.01) was noted. At univariate analysis, clinical stage III (p < 0.001), radiotherapy dose >5040 cGy (p = 0.002) and longer interval (p < 0.001) were significantly correlated to pCR. The positive impact of interval (p < 0.001) was confirmed at multivariate analysis as the only correlated factor. CONCLUSION: We confirmed on a population-level that lengthening the interval (>13 weeks) from CRT to surgery improves the pathological response (pCR and pathologic partial response; pPR) in comparison to historic data. Furthermore, radiotherapy dose >5040 cGy and two drugs chemotherapy correlated with pPR rate.

[(18)F]Choline PET/CT and stereotactic body radiotherapy on treatment decision making of oligometastatic prostate cancer patients: preliminary results.

BACKGROUND: A new entity of patients with recurrent prostate cancer limited to a small number of active metastatic lesions is having growing interest: the oligometastatic patients. Patients with oligometastatic disease could eventually be managed by treating all the active lesions with local therapy, i.e. either surgery or ablative stereotactic body radiotherapy. This study aims to assess the impact of [(18)F]Choline ([(18)F]FMCH) PET/CT and the use stereotactic body radiotherapy (SBRT) in patients (pts) with oligometastatic prostate cancer (PCa). METHODS: Twenty-nine pts with oligometastatic PCa (≤3 synchronous active lesions detected with [(18)F]FMCHPET/CT) were treated with repeated salvage SBRT until disease progression (development of > three active synchronous metastases). Primary endpoint was systemic therapy-free survival measured from the baseline [(18)F]FMCHPET/CT. RESULTS: A total of 45 lesions were treated with SBRT. After a median follow-up of 11.5 months (range 3-40 months), 20 pts were still in the study and did not receive any systemic therapy. Nine pts started systemic therapy, and the median time of the primary endpoint was 39.7 months (CI 12.20-62.14 months). No grade 3 or 4 toxicity was recorded. CONCLUSIONS: Repeated salvage [(18)F]FMCHPET/CT-guided SBRT is well tolerated and could defer the beginning of systemic therapy in selected patients with oligometastatic PCa.

Patterns of radiotherapy practice for pancreatic cancer: Results of the Gastrointestinal Radiation Oncology Study Group multi-institutional survey.

No information is currently available regarding pancreatic cancer (PC) pattern of care in Italy. In the present study, a nationwide survey using a questionnaire was performed to enquire the local standards for PC diagnosis and radiotherapy treatment. Fifty-seven percent of 140 Italian centres completed questionnaire. The main causes of no radiotherapy indication were poor general condition (45%) and lack of guidelines (25%). Physicians (38%) employed neoadjuvant therapy in locally advanced PC patients, while in other centres (62%) adjuvant chemoradiation was administered. Adjuvant gemcitabine-based chemotherapy was selected as the treatment of choice by 59% of centres. Patients were treated mostly with doses of 50-54.9 Gy on the tumour (or bed) plus lymph nodes. A 3D-CRT technique was used in 81.2% of centres, while IMRT and IGRT were available in 61.2 and 48.7% of cases, respectively. Extensive variation exists with regard to patterns of care for PC in Italy. Nevertheless, cooperative studies emerging from this survey appeared beneficial.

Selection of appropriate end-points (pCR vs 2yDFS) for tailoring treatments with prediction models in locally advanced rectal cancer.

PURPOSE: Personalized treatments based on predictions for patient outcome require early characterization of a rectal cancer patient's sensitivity to treatment. This study has two aims: (1) identify the main patterns of recurrence and response to the treatments (2) evaluate pathologic complete response (pCR) and two-year disease-free survival (2yDFS) for overall survival (OS) and their potential to be relevant intermediate endpoints to predict. METHODS: Pooled and treatment subgroup analyses were performed on five large European rectal cancer trials (2795 patients), who all received long-course radiotherapy with or without concomitant and/or adjuvant chemotherapy. The ratio of distant metastasis (DM) and local recurrence (LR) rates was used to identify patient characteristics that increase the risk of recurrences. FINDINGS: The DM/LR ratio decreased to a plateau in the first 2 years, revealing it to be a critical follow-up period. According to the patterns of recurrences, three patient groups were identified: 5-15% had pCR and were disease free after 2 years (excellent prognosis), 65-75% had no pCR but were disease free (good prognosis) and 15-30% had neither pCR nor 2yDFS (poor prognosis). INTERPRETATION: Compared with pCR, 2yDFS is a stronger predictor of OS. To adapt treatment most efficiently, accurate prediction models should be developed for pCR to select patients for organ preservation and for 2yDFS to select patients for more intensified treatment strategies.

Inter-observer variability of clinical target volume delineation in radiotherapy treatment of pancreatic cancer: a multi-institutional contouring experience.

BACKGROUND: An observational multi-institutional study has been conducted aimed to evaluate the inter-observer variability in clinical target volume (CTV) delineation among different radiation oncologists in radiotherapy treatment of pancreatic cancer. METHODS: A multi-institutional contouring dummy-run of two different cases of pancreatic cancer treated by postoperative and preoperative radiotherapy (RT) was performed. Clinical history, diagnostics, and planning CT imaging were available on AIRO website (http://www.radioterapiaitalia.it). Participants were requested to delineate CTVs according to their skills and knowledge. Aiming to quantify interobserver variability of CTVs delineations, the total volume, craniocaudal, laterolateral, and anteroposterior diameters were calculated. Descriptive statistic was calculated. The 95% Confidence Interval (95% CI) for coefficient of variation (CV) was estimated. The Dice Similarity Index (DSI) was used to evaluate the spatial overlap accuracy of the different CTVs compared with the CTVs of a national reference Centre considered as a benchmark. The mean DSI (mDSI) was calculated and reported. RESULTS: A total of 18 radiation oncologists from different Institutes submitted the targets. Less variability was observed for the Elective CTV rather than the Boost CTV, in both cases. The estimated CV were 28.8% (95% CI: 21.2-45.0%) and 20.0% (95% CI: 14.9-30.6%) for the Elective CTV, in adjuvant (Case 1) and neoadjuvant (Case 2) case, respectively. The mDSI value was 0.68 for the Elective CTVs in both cases (range 0.19-0.79 in postoperative vs range 0.35-0.79 in preoperative case). The mDSI was increased to 0.71 (Case 1) and 0.72 (Case 2) if the observers with a worse agreement have been excluded. On the other hand, a CV of 42.4% (95% CI: 30.1-72.4%) and 63.8% (95% CI: 43.9-119.2%) with a mDSI value of 0.44 and 0.52, were calculated for the Boost CTV in Case 1 and Case 2, respectively. CONCLUSIONS: The CV and mDSI obtained values for Elective CTVs showed an acceptable agreement among participants either in postoperative as well in preoperative setting. Additional strategies to reduce the variability in Boost CTV delineation need to be found and promoted.