Variability of clinical target volume delineation for rectal cancer patients planned for neoadjuvant radiotherapy with the aid of the platform Anatom-e

Objective: Delineation of treatment volumes is a major source of uncertainties in radiotherapy (RT). This is also true for rectal cancer patients undergoing neoadjuvant RT, with a potential impact on treatment quality. We investigated the role of the digital platform Anatom-e (Anatom-e Information Sytems Ltd., Houston, Texas) in increasing the compliance to follow a specific treatment protocol in a multicentric setting. Materials and methods: Two clinical cases of locally advanced rectal cancer were chosen. Participants were instructed to follow the 2009 Radiation Therapy Oncology Group consensus atlas and asked to manually segment clinical target volumes (CTVs), for both patient 1 and 2, on day 1 with and without the use of Anatom-e. After one week (day 2), the same radiation oncologist contoured again, with and without Anatom-e, the same CT series. Intraobserver (Intra-OV) and interobserver (Inter-OV) variability were evaluated with the Dice similarity coefficient (DSC), the Hausdorff distance (HD) and mean distance to agreement (MDA). Results: For clinical case 1, no significant difference was found for Intra-OV and Inter-OV. For clinical case 2, no significant difference was found for Intra-OV but a statistically significant difference was found for Inter-OV in DSC when using or not the platform. Mean DCS was 0.65 (SD: ±0.64; range: 0.58–0.79) for day 1 vs reference volume without Anatom-e and 0.72 (SD: ±0.39; range: 0.67–0.77) (p = 0.03) with it. Mean MDA was lower with Anatom-e (3.61; SD: ±1.33; range: 2.85–4.78) than without (4.14; SD: ±2.97; range: 2.18–5.21), with no statistical significance (p = 0.21) The use of Anatom-e decreased the SD from 2.97 to 1.33. Mean HD was lower with Anatom-e (26.06; SD: ±2.05; range: 24.08–32.62), with no statistical significance (p = 0.14) compared to that without (31.39; SD: ±1.31; range: 26.14–48.72). Conclusions: The use of Anatom-e decreased the Inter-OV in the CTV delineation process for locally advanced rectal cancer with complex disease presentation planned for neoadjuvant RT. This system may be potentially helpful in increasing the compliance to follow shared guidelines and protocols. Keywords: Rectal cancer, Neoadjuvant radiotherapy, Interobserver variability, Contouring, Target volume delineatio

Incorporating 18FDG-PET-defined pelvic active bone marrow in the automatic treatment planning process of anal cancer patients undergoing chemo-radiation

Abstract Background To investigate whether the incorporation of 18FDG-PET into the automatic treatment planning process may be able to decrease the dose to active bone marrow (BM) for locally advanced anal cancer patients undergoing concurrent chemo-radiation (CHT-RT). Methods Ten patients with locally advanced anal cancer were selected. Bone marrow within the pelvis was outlined as the whole outer contour of pelvic bones or employing 18FDG-PET to identify active BM within osseous structures. Four treatment planning solutions were employed with different automatic optimization approaches toward bone marrow. Plan A used iliac crests for optimization as per RTOG 05–29 trial; plan B accounted for all pelvic BM as outlined by the outer surface of external osseous structures; plan C took into account both active and inactive BM as defined using 18FDG-PET; plan D accounted only for the active BM subregions outlined with 18FDG-PET. Dose received by active bone marrow within the pelvic (ACTPBM) and in different subregions such as lumbar-sacral (ACTLSBM), iliac (ACTIBM) and lower pelvis (ACTLPBM) bone marrow was analyzed. Results A significant difference was found for ACTPBM in terms of Dmean (p = 0.014) V20 (p = 0.015), V25 (p = 0.030), V30 (p = 0.020), V35 (p = 0.010) between Plan A and other plans. With respect to specific subsites, a significant difference was found for ACTLSBM in terms of V30 (p = 0.020)), V35 (p = 0.010), V40 (p = 0.050) between Plan A and other solutions. No significant difference was found with respect to the investigated parameters between Plan B,C and D. No significant dosimetric differences were found for ACTLSPBM and ACTIBM and inactive BM subregions within the pelvis between any plan solution. Conclusions Accounting for pelvic BM as a whole compared to iliac crests is able to decrease the dose to active bone marrow during the planning process of anal cancer patients treated with intensity-modulated radiotherapy. The same degree of reduction may be achieved optimizing on bone marrow either defined using the outer bone contour or through 18FDG-PET imaging. The subset of patients with a benefit in terms of dose reduction to active BM through the inclusion of 18FDG-PET in the planning process needs further investigation

Stereotactic ablative radiation therapy prior to liver transplantation in hepatocellular carcinoma

OBJECTIVE: Stereotactic ablative radiotherapy (SABR) is a safe treatment approach for hepatocellular carcinoma (HCC) with comparable effectiveness to other local therapies. Only scant information is available concerning the role of SABR prior to liver transplantation (LT) for HCC. We present a consecutive case series investigating the role of SABR as a bridge or downstaging option in HCC patients subsequently submitted to LT. MATERIALS AND METHODS: Between September 2012 and May 2014, 8 patients for a total of 13 lesions underwent SABR prior to LT. Inclusion criteria were a pathological or radiological diagnosis of HCC, lesion size ≤6 cm or lesion number ≤3 with a total diameter ≤6 cm, no extrahepatic metastases, Child-Pugh class A-B, ECOG performance status ≤1. Patients were prescribed 36-48 Gy in 3-5 fractions (8 Gy × 5 fractions or 16 Gy × 3 fractions), in 3-5 consecutive days according to clinical and dosimetric decision making. Radiological response was evaluated according to the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Pathological response was assessed through the rate of tumor necrosis relative to the total tumor volume. Acute and late toxicities were scored using the National Cancer Institute Common Terminology Criteria for Adverse Events version 4 (CTCAE v 4.0). RESULTS: Among the 13 pathologically evaluated lesions, 8 (61.5 %) lesions had a complete response 2 (15.3 %) had a minimal pathological response and other 2 (15.3 %) showed stable disease. The remaining lesion had a significant pathological response. Maximum detected toxicity included a G2 GGT increase in two patients (at 1 and 3 months respectively). One patient developed a non-classic RILD with a fivefold increase in transaminase enzymes level and a shift in Child-Pugh category from B7 to C10 due to bilirubin increase. Only one modification in the surgical strategy was needed during LT. CONCLUSIONS: SABR proved to be a safe and effective local therapy prior to LT in HCC patients. Prospective controlled clinical trials are needed to evaluate its efficacy compared to other local therapies in this setting

No differences in radiological changes after 3D conformal vs VMAT-based stereotactic radiotherapy for early stage non-small cell lung cancer

OBJECTIVE: To compare patterns of acute and late radiological lung injury following either 3D conformal or image-guided volumetric modulated arc therapy stereotactic radiotherapy for Stage I non-small-cell lung cancer. METHODS: We included 148 patients from a prospective mono-institutional stereotactic body radiation therapy (SBRT) series (time interval 2004-2014), treated with prescription BED10 Gy (at 80%) in the range 100-120 Gy. The first 95 patients (2004-2010) were planned with 3D-CRT, with a stereotactic body frame. The second cohort (2010-2014) included 53 patients, planned with volumetric IMRT on a smaller planning target volume generated from a patient's specific internal target volume, with a frameless approach through cone-beam CT guidance. Acute and late radiological modifications were scored based on modified Kimura's and Koenig's classifications, respectively. RESULTS: Median follow-up time was 20.5 months. The incidence of acute radiological changes was superimposable between the groups: increased density was observed in 68.4 and 64.2% of patients for 3D-CRT and VMAT, respectively, and patchy ground glass opacity in 23.7 and 24.5%, respectively; diffuse ground glass opacity was 2.6 vs 9.4%, respectively, and patchy consolidation 2.6 vs 1.9%, respectively. Late changes occurred in approximately 60% of patients: modified conventional pattern was the most frequent modification (25 vs 32.6%, respectively); other patterns were less common (mass-like 19.6 vs 17.4%, and scar-like 13 vs 10.9%, respectively). CONCLUSION: Results of the present study indicate that the pattern of radiological lung changes following SBRT for peripheral early stage non-small-cell lung cancer is not influenced by the different techniques used for planning and delivery. Advances in knowledge: This comparative observational study shows that smaller margins, image guidance and most importantly dose distribution do not change the pattern of radiological injury after lung SBRT; the same scoring system can be used, and expected incidence is similar