To analyze hepatic failure progression in patients with Barcelona Clinic Liver Cancer (BCLC) A3-B Hepatocellular Carcinoma (HCC) after SRT with functional treatment planning. Twenty-two patients with BCLC stage A3-B HCC completed treatment planning with 99mTc-sulfur colloid liver SPECT co-registered to 4DCT for avoidance of best functional hepatic parenchyma during SRT. Liver dose constraints were imposed on functional liver volume defined on 3D-CT/SPECT. Dose per fraction varied based on surrounding normal tissue tolerances. When fraction size fell below 4 Gy patients received concurrent radiosensitizing capecitabine. Hepatic function was evaluated by Child-Pugh and MELD scores every 4 months. Toxicities were graded according to the Common Terminology Criteria for Adverse Events (v4.03). Local response with contrast-enhanced multiphase CT or MRI was documented every 4-6 months following radiation therapy. Twenty-two patients with 39 lesions were analyzed under IRB approved consent. Prior to therapy, 14 (64%) patients had Child Pugh A and 8 (36%) had Child Pugh B Cirrhosis. Twelve patients (55%) had pre-treatment MELD score > 9. Fourteen patients (9 Child Pugh A and 5 Child Pugh B) received SBRT (mean dose of 44.7 Gy in 5-6 fractions). Mean diameter for lesions treated with SBRT was 6.2 cm (range 5-8.9 cm). Eight patients (5 Child Pugh A and 3 Child Pugh B) with a mean tumor diameter of 8.3 cm (range 5.7-14.9 cm) received fractionated SRT and concurrent capecitabine to a mean dose of 40.7 Gy in 14-18 fractions. With mean follow up of 20 months, 9 patients with pretreatment abnormal liver function developed acute grade ≤ 2 transient elevation of liver enzymes (LFT). At 24 months, Child-Pugh class did not change in 59% of patients and MELD progression free survival was 76% based on Kaplan Meier Analysis. No incidence of RILD or accelerated progression of hepatic failure was observed. In-field local control was 97.4%. Overall survival at 2 years was 59%, comparable to all-cause mortality in a cirrhotic cohort. Liver SRT based on functional treatment planning is safe in locally advanced hepatocellular carcinoma. Progression of cirrhosis is not hastened despite the inclusion of 36% Child-Pugh B patients.

The purpose of this study was to analyze the cause of intrafraction motion during lung stereotactic body radiation therapy (SBRT) treatment. High tumor control is achieved by delivering a radiation dose to a lung nodule in a small number of fractions. To limit toxicity to normal tissue small Planning Target Volume (PTV) margins are used, requiring an accurate localization system. ASTRO and AAPM guidelines emphasize the use of an image guidance system to reduce interfraction patient setup uncertainty as well as reliable patient immobilization to control intrafraction motion. One hundred eight treatment fractions for 32 lung patients were analyzed. Patients were immobilized in an extended Vacbag with arms over the head in the supine position. No active breathing control or breathing restriction device was used. Prior to each treatment, a MV-CBCT was acquired. Lateral (LR), longitudinal (SI) and vertical (AP) offsets were extracted and applied to the treatment couch then treatment was initiated. Five to 9 beams were used with up to 3 non-coplanar beams requiring couch kicks. A second MV-CBCT was acquired after completion of treatment. The pre- and post-treatment CBCTs were registered twice, focusing on tumor, then spine, alignment, in order to separate patient body motion from tumor motion inside the patient. Offsets extracted from both registrations were analyzed, as well as the difference between the two registrations. The percentages of treatment fractions during which intrafraction motion exceeded 3 and 5 mm margins were calculated. The mean time between the two CBCT acquisitions was 26 min (range, 17-48). The mean and standard deviation for the offsets based on tumor registration, spine registration and tumor-spine difference are presented in Table I. Intrafraction tumor motion exceeded 3 and 5 mm margins in 36% and 6% of the cases, respectively.Poster Viewing Abstract 3320; TableLR (mm)SI (mm)AP (mm)3D (mm)Tumor (overall tumor motion)0.1 ± 1.30.4 ± 2.2−0.2 ± 1.92.8 ± 1.5Spine (body motion)0.1 ± 1.20.2 ± 1.10.2 ± 1.31.8 ± 1.1Difference (tumor motion inside body)0.0 ± 1.20.2 ± 2.0−0.4 ± 1.92.6 ± 1.6 Open table in a new tab The largest contribution to intrafraction tumor motion is not from body motion, but from tumor motion inside the patient. It should be noted that this motion does not represent the breathing cycle, which is averaged out over the CBCT acquisition. It may rather represent changes in breathing pattern during the course of delivery, which could potentially be reduced with the use of an active breathing control device. Results show that overall motion is small and a 5 mm PTV margin is appropriate.

Evaluate the feasibility, safety, and efficacy of SRT in combination with hepatic resection of primary and metastatic liver tumors. Sixteen patients completed hepatectomy and SRT for either hepatocellular carcinoma (HCC) (6) or metastases from colorectal (5), neuroendocrine (2), uterine (2), or sarcoma (1) primary. Twenty-one operable metastases were resected in 5 patients and gold fiducials were placed into the unresectable lesions to facilitate definitive SRT. Three patients with initially unresectable tumors received preoperative SRT followed by R0 resection. SRT as a bridge to liver transplant was used in 4 patients with HCC. Four patients had salvage SRT for recurrence after surgery. All patients completed 4D-CT and 3D-SPECT/CT to define functional normal liver volume (NLV) for SRT planning. MV-fluoro was performed to confirm tumor/fiducial respiratory motion within the PTV. In retrospect, our patient's treatment planning, clinical, laboratory, and imaging data were reviewed under an IRB approved outcomes study. Toxicity was graded according to CTCAE v3.0. All patients successfully completed a combination of hepatectomy and SRT. Forty lesions were treated with hepatectomy and 20 (≤ 3 per patient) received SRT with a mean PTV of 132.6 cc (range, - 9.7-803.5). The mean dose was 47.7 Gy (range, - 36-60) prescribed to the PTV in 5-16 fractions. With median follow-up of 17.7 months (range, - 5.8-32.1), 2 patients had grade 3 elevation of Total Bilirubin prior to initiation of SRT which persisted through treatment. No incidence of > grade 1 radiation-induced liver disease was observed. The most common clinical toxicity was Grade ≤ 2 fatigue. No patients had grade > 2 clinical toxicity. As a group, functional NLVs defined on 3D-SPECT/CT were significantly reduced compared to liver volumes defined on CT and estimated from the Body Surface Area equation (p = 0.037 and p = 0.0012 respectively). Postoperative morbidity was ≤ Grade 1. On follow-up imaging, no in-field failures have occurred. A total of 18.7% of the patients have had a failure elsewhere in the liver. Overall survival was 75% with 4 deaths, 2 of which were from liver failure and 2 from progressive systemic disease. Our preliminary study indicates that combination of liver SRT with hepatic resection is safe and effective. It can be used preoperatively to increase resectability or postoperatively to salvage surgical failures. It can also be used to target unresectable metastases in combination with limited hepatectomies for resectable peripheral lesions thereby expanding indications for curative treatment. SRT planning with 3D-SPECT/CT allows identification and preservation of the functional NLV.