Gian Carlo Mattiucci

Intensity-modulated radiotherapy with simultaneous integrated boost to dominant intraprostatic lesion: preliminary report on toxicity.

ObjectivesTo evaluate the feasibility of intensity-modulated radiotherapy with simultaneous integrated boost to the dominant intraprostatic lesion for definitive treatment of prostate cancer. Materials and MethodsPatients were deemed eligible for the study if they had histologically proven stage cT2-T3 N0M0 prostate adenocarcinoma. In addition <20% risk of lymph nodal involvement according to Roach formula, was required for enrollment. Patients were treated with intensity-modulated radiotherapy with simultaneous integrated boost technique to the dominant intraprostatic lesion defined by magnetic resonance imaging. The prescribed dose to the prostate and seminal vesicles was 72 Gy (1.8 Gy per fraction). The dose delivered to the intraprostatic lesion received was 80 Gy (2 Gy per fraction). Acute gastrointestinal (GI) and genitourinary (GU) toxicity was evaluated weekly during treatment, and at 1 and 3 months thereafter. Late GI and GU toxicity was evaluated by Kaplan Meier method. ResultsForty patients were deemed evaluable. Acute and late GI and GU toxicity were evaluated in all patients. Two patients (5%) developed acute grade 3 GI toxicity and 1 patient (2.5%) developed acute grade 3 GU toxicity. No grade 4 acute GI or GU toxicity occurred. With a median follow-up of 19 months (interquartile range, 15 to 26 mo), the 2-year actuarial cumulative incidence of grade ≥2 rectal toxicity was 9.5%. The 2-year actuarial cumulative incidence of grade ≥2 urinary toxicity was 13.3%. ConclusionsTreatment related acute toxicity was low in our cohort. Prolonged observation with a larger series of patients is necessary to evaluate late toxicity and local control.

The Prognostic Effect of Clinical Staging in Pancreatic Adenocarcinoma

BackgroundThe importance of pancreatic cancer staging is uncertain. The aim of this report was to evaluate the accuracy of combined standard imaging techniques in predicting the pathologic stage and to evaluate the prognostic effect of clinical staging to identify patient groups in which laparoscopy and laparotomy could be beneficial.MethodsFifty-four patients were included in this analysis. The techniques used for clinical staging were endoscopic retrograde cholangiopancreatography, abdominal computed tomographic scan, and ultrasonography. All patients underwent both clinical and surgical/pathologic staging. A comparison was performed between presurgical stage and surgical/pathologic stage. The prognostic effect of different factors on survival was evaluated with both univariate (log-rank) and multivariate (Cox) analysis.ResultsSensitivity and specificity for vascular involvement were 73.9% and 96.3%, respectively. Sensitivity and specificity for nodal involvement were 63.6% and 95.4%, respectively. A total of 33.3% of patients showed a higher than expected pathologic stage, and 3.7% showed a lower than expected pathologic stage, by comparing clinical and pathologic evaluation. A highly significant correlation was observed between clinical T stage (P = .0067) and tumor diameter (P = .0037) and patient survival. Maximal prognostic differentiation was observed by dividing patients into two groups based on imaging results: group A (favorable prognosis) and group B (unfavorable prognosis). The median survival was 25.1 and 8.0 months for group A and B, respectively. Five-year survival was 20.1% and 0%, respectively (multivariate analysis: P = .0007).ConclusionsIntegrated standard imaging studies achieved reasonable diagnostic accuracy in our analysis. A single classification based on clinical stage and tumor diameter evaluated by imaging predicts prognosis in patients with pancreatic carcinoma.

Integration between in vivo dosimetry and image guided radiotherapy for lung tumors

The article reports a feasibility study about the potentiality of an in vivo dosimetry method for the adaptive radiotherapy of the lung tumors treated by 3D conformal radiotherapy techniques (3D CRTs). At the moment image guided radiotherapy (IGRT) has been used for this aim, but it requires taking many periodic radiological images during the treatment that increase workload and patient dose. In vivo dosimetry reported here can reduce the above efforts, alerting the medical staff for the commissioning of new radiological images for an eventual adaptive plan. The in vivo dosimetry method applied on 20 patients makes use of the transit signal St on the beam central axis measured by a small ion chamber positioned on an electronic portal imaging device (EPID) or by the EPID itself. The reconstructed in vivo dosimetry at the isocenter point Diso requires a convolution between the transit signal St and a dose reconstruction factor C that essentially depends on (i) tissue inhomogeneities along the beam central axis and (ii) the in-patient isocenter depth. The C factors, one for every gantry angle, are obtained by processing the patients computed tomography scan. The method has been recently applied in some Italian centers to check the radiotherapy of pelvis, breast, head, and thorax treatments. In this work the dose reconstruction was carried out in five centers to check the Diso in the lung tumor during the 3D CRT, and the results have been used to detect the interfraction tumor anatomy variations that can require new CT imaging and an adaptive plan. In particular, in three centers a small ion chamber was positioned below the patient and used for the St measurement. In two centers, the St signal was obtained directly by 25 central pixels of an a-Si EPID, equipped with commercial software that enabled its use as a stable detector. A tolerance action level of +/- 6% for every checked beam was assumed. This means that when a difference greater than 6% between the predicted dose by the treatment planning system, Diso,TPS, and the Diso was observed, the clinical action started to detect possible errors. 60% of the patients examined presented morphological changes during the treatment that were checked by the in vivo dosimetry and successively confirmed by the new CT scans. In this work, a patient that showed for all beams Diso values outside the tolerance level, new CT scans were commissioned for an adaptive plan. The lung dose volume histograms (DVHs) for a Diso,TPs=2 Gy for fraction suggested the adaptive plan to reduce the dose in lung tissue. The results of this research show that the dose guided radiotherapy (DGRT) by the Diso reconstruction was feasible for daily or periodic investigation on morphological lung tumor changes. In other words, since during 3D CRT treatments the anatomical lung tumor changes occur frequently, the DGRT can be well integrated with the IGRT.

Effect of whole pelvic radiotherapy for patients with locally advanced prostate cancer treated with radiotherapy and long-term androgen deprivation therapy

PURPOSE To evaluate the effect of whole pelvic radiotherapy (WPRT) in prostate cancer patients treated with RT and long-term (>1 year) androgen deprivation therapy (ADT). METHODS AND MATERIALS Prostate cancer patients with high-risk features (Stage T3-T4 and/or Gleason score≥7 and/or prostate-specific antigen level≥20 ng/mL) who had undergone RT and long-term ADT were included in the present analysis. Patients with bowel inflammatory disease, colon diverticula, and colon diverticulitis were excluded from WPRT and treated with prostate-only radiotherapy (PORT). Patients were grouped according to nodal risk involvement as assessed by the Roach formula using different cutoff levels (15%, 20%, 25%, and 30%). Biochemical disease-free survival (bDFS) was analyzed in each group according to the RT type (WPRT or PORT). RESULTS A total of 358 patients treated between 1994 and 2007 were included in the analysis (46.9% with WPRT and 53.1% with PORT). The median duration of ADT was 24 months (range, 12-38). With a median follow-up of 52 months (range, 20-150), the overall 4-year bDFS rate was 90.5%. The 4-year bDFS rate was similar between the patients who had undergone WPRT or PORT (90.4% vs. 90.5%; p=NS). However, in the group of patients with the greatest nodal risk (>30%), a significant bDFS improvement was recorded for the patients who had undergone WPRT (p=.03). No differences were seen in acute toxicity among the patients treated with WPRT or PORT. The late gastrointestinal toxicity was similar in patients treated with PORT or WPRT (p=NS). CONCLUSIONS Our analysis has supported the use of WPRT in association with long-term ADT for patients with high-risk nodal involvement (>30%), although a definitive recommendation should be confirmed by a randomized trial.

Multi-institutional pooled analysis on adjuvant chemoradiation in pancreatic cancer

PURPOSE To determine the impact of chemoradiation therapy (CRT) on overall survival (OS) after resection of pancreatic adenocarcinoma. METHODS AND MATERIALS A multicenter retrospective review of 955 consecutive patients who underwent complete resection with macroscopically negative margins (R0-1) for invasive carcinoma (T1-4; N0-1; M0) of the pancreas was performed. Exclusion criteria included metastatic or unresectable disease at surgery, macroscopic residual disease (R2), treatment with intraoperative radiation therapy (IORT), and a histological diagnosis of no ductal carcinoma, or postoperative death (within 60 days of surgery). In all, 623 patients received postoperative radiation therapy (RT), 575 patients received concurrent chemotherapy (CT), and 462 patients received adjuvant CT. RESULTS Median follow-up was 21.0 months. Median OS after adjuvant CRT was 39.9 versus 24.8 months after no adjuvant CRT (P<.001) and 27.8 months after CT alone (P<.001). Five-year OS was 41.2% versus 24.8% with and without postoperative CRT, respectively. The positive impact of CRT was confirmed by multivariate analysis (hazard ratio [HR] = 0.72; confidence interval [CI], 0.60-0.87; P=.001). Adverse prognostic factors identified by multivariate analysis included the following: R1 resection (HR = 1.17; CI = 1.07-1.28; P<.001), higher pT stage (HR = 1.23; CI = 1.11-1.37; P<.001), positive lymph nodes (HR = 1.27; CI = 1.15-1.41; P<.001), and tumor diameter >20 mm (HR = 1.14; CI = 1.05-1.23; P=.002). Multivariate analysis also showed a better prognosis in patients treated in centers with >10 pancreatic resections per year (HR = 0.87; CI = 0.78-0.97; P=.014) CONCLUSION: This study represents the largest comparative study on adjuvant therapy in patients after resection of carcinoma of the pancreas. Overall survival was better in patients who received adjuvant CRT.

Clinical validation of atlas-based auto-segmentation of pelvic volumes and normal tissue in rectal tumors using auto-segmentation computed system

Abstract Purpose. To evaluate in two different settings – clinical practice and education/training – the reliability, time efficiency and the ideal sequence of an atlas-based auto-segmentation system in pelvic delineation of locally advanced rectal cancer. Methods. Fourteen consecutive patients were selected between October and December 2011. The images of four were used as an atlas and 10 used for validation. Two independent operators participated: a Delineator to contour and a Reviewer to perform an independent check (IC). The CTV, pelvic subsites and organs at risk were contoured in four different sequences. These included A: manual; B: auto-segmentation; C: auto-segmentation + manual revision; and D: manual + auto-segmentation + manual revision. Contouring was performed by the Delineator using the same planning CT. All of them underwent an IC by a Reviewer. The time required for all the contours were recorded and overlapping evaluation was assessed using a Dice coefficient. Results. In the clinical practice setting there have been 13 minutes time saved between sequences A versus sequences B (from 38 to 25 minutes, p = 0.002), a mean Dice coefficient in favor of sequences A for CTV and all subsites (p = 0.0195). In the educational/training setting there have been 35.2 minutes time saved between sequences C and D 8 (from 73.1 min to 37.9 min, p = 0.002). Conclusion. The preliminary data suggest that the use of an atlas-based auto-contouring system may help improve efficiencies in contouring in the clinical practice setting and could have a tutorial role in the educational/training setting.

Automatic delineation for replanning in nasopharynx radiotherapy: What is the agreement among experts to be considered as benchmark?

Abstract Background and purpose. Anatomic changes during head and neck radiotherapy require replanning. The primary aim of this study is the definition of the agreement among experts in the head and neck automatic delineation frame to use as benchmark. The secondary goal is to assess the reliability of automatic delineation for nasopharynx radiotherapy and time saving. Material and methods. A computed tomography (CT) scan was acquired in 10 nasopharynx patients along intensity-modulated radiotherapy (IMRT) treatment for replanning. Deformable registration with replanning autocontouring of the structures was performed using VelocityAI 2.3© software defining Structure Set A. The optimization of these contours was obtained through revision by a skilled operator, drawing Structure Set B. An ex novo Structure Set C was segmented on the replanning CT-scan by an expert delineation team. The mean Dices Similarity Index (mDSI) was calculated between Structure Set A and B, A and C, and between B and C for each volume. All segmentation times for organs at risk (OARs) and clinical target volume (CTV) were recorded and compared. Results. We validated the replanning autocontoured Structure Sets for 10 patients. For volumetric analysis we observed mDSI values of 0.87 for the OARs, 0.70 for nodes, 0.90 for CTV in the Structure Set A-B comparison and respectively of 0.74, 0.63 and 0.78 for the Structure Set A-C one, and 0.78, 0.78 and 0.85 for Structure Set B-C, which represents the existing expert based benchmark. We calculated a mean saved time in Structure Set B of 30 minutes. Conclusions. Autocontouring procedures offer considerable segmentation time saving with acceptable reliability of the contours, even if an independent check procedure for their optimization is still required to increase their adherence to referential benchmark gold standard among experts, which stands at a 0.80 DSI value.

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

BackgroundAn 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.MethodsA 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.ResultsA 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.ConclusionsThe 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.

Low-Dose Hyperradiosensitivity: Is There a Place for Future Investigation in Clinical Settings?

BACKGROUND AND PURPOSE In vitro radiation doses of below 0.5 Gy have been shown to be more effective than higher doses per unit dose in killing clonogenic cells of many epithelial tumor cell lines. This phenomenon is known as low-dose hyperradiosensitivity. Preclinical studies have now suggested that there is synergism between chemotherapy and low-dose fractionated radiotherapy (LD-FRT). To test the clinical efficacy of this approach, we prospectively evaluated concurrent palliative chemotherapy and LD-FRT in patients with various types of epithelial tumors. METHODS AND MATERIALS Patients suffering from relapses or metastases of epithelial tumors were scheduled to receive concurrent LD-FRT (two fractions of 0.4 Gy per day) and chemotherapy. Radiologic assessments were performed after three cycles of chemotherapy plus LD-FRT. RESULTS Between June 2006 and October 2007, 12 patients with lung cancer, 7 patients with head-and-neck tumors, 2 patients with breast cancer, and 1 patient with esophageal carcinoma, for a total patient population of 22, underwent concomitant LD-FRT and chemotherapy. All patients but 3 (86%) had received previous treatments for their cancer. The median total dose of LD-FRT delivered was 800 cGy (range, 320-1280 cGy). The overall response rate was 45% (42% in previously treated patients). Grade 3-4 hematologic toxicities (Radiation Therapy Oncology Group ratings) were observed in 2 patients. At a median follow-up of 6.5 months, however, no local toxicity was observed. CONCLUSION In our experience, concurrent LD-FRT and chemotherapy was well tolerated. Because the response rate seems promising, prospective Phase II studies of the strategy are now under way.

Early proctoscopy is a surrogate endpoint of late rectal toxicity in prostate cancer treated with radiotherapy.

PURPOSE To predict the grade and incidence of late clinical rectal toxicity through short-term (1 year) mucosal alterations. METHODS AND MATERIALS Patients with prostate adenocarcinoma treated with curative or adjuvant radiotherapy underwent proctoscopy a year after the course of radiotherapy. Mucosal changes were classified by the Vienna Rectoscopy Score (VRS). Late toxicity data were analyzed according to the Kaplan-Meier method. Comparison between prognosis groups was performed by log-rank analysis. RESULTS After a median follow-up time of 45 months (range, 18-99), the 3-year incidence of grade ≥ 2 rectal late toxicity according to the criteria of the European Organization for Research and Treatment of Cancer and the Radiation Therapy Oncology Group was 24%, with all patients (24/24; 100%) experiencing rectal bleeding. The occurrence of grade ≥ 2 clinical rectal late toxicity was higher in patients with grade ≥ 2 (32% vs. 15 %, p = 0.02) or grade ≥ 3 VRS telangiectasia (47% vs. 17%, p ≤ 0.01) and an overall VRS score of ≥ 2 (31% vs. 16 %, p = 0.04) or ≥ 3 (48% vs. 17%, p = 0.01) at the 1-year proctoscopy. CONCLUSIONS Early proctoscopy (1 year) predicts late rectal bleeding and therefore can be used as a surrogate endpoint for late rectal toxicity in studies aimed at reducing this frequent complication.