Author Disclosure: J.M. Robertson, None; M. Soehn, None; D. Yan, None.

2165 Successful Downstaging of Upper Rectal and Distal Sigmoid Tumours By PreoperativeChemo-Radiotherapy

B. D. P. O’Neill, G. Brown, D. M. Tait

Royal Marsden Hospital, London, United Kingdom

Purpose/Objective(s): For tumours above the peritoneal reflection, the benefit of preoperative Chemo-Radiotherapy (CRT) isnot clear, with perceived increased toxicity and reduced efficacy compared to lower rectal tumours. The risk of a positivecircumferential resection margin (CRM) can be accurately predicted by pre-operative MRI, in addition to identifying high risktumours from upper rectum to distal sigmoid. We have treated a group of high-risk locally advanced tumours above theperitoneal reflection with preoperative CRT in order to achieve downstaging.

Materials/Methods: 17 patients with high rectal, recto-sigmoid or distal sigmoid cancers with T4 or ‘threatened’ CRM by MRIcriteria, received neo-adjuvant CRT. All tumours were above the peritoneal reflection. The lower limit for upper rectal tumourswas 10cm above the anal verge, 12 cm for recto-sigmoid tumours, and 15cm for distal sigmoid tumours. All patients received45 Gy in 25 fractions, CT-planned conformal RT, with concomitant chemotherapy, and a boost of 5.4 - 9 Gy. Patients werereviewed weekly during CRT, and 2 weeks prior to surgery. Surgery was performed at 6 weeks following completion of CRT.Late toxicity was assessed at each follow-up visit.

Results: Median follow-up is 37 months. Overall survival is 82.35% and disease free survival 70.59%. Loco-regional relapserate is 5.88%. 15 patients received 54 Gy in 30 fractions, and 2 patients 50.4 Gy in 28 fractions. 12 patients were administered4 cycles of preoperative Oxaliplatin (130mg/m2 IV q21 days), and Capecitabine (1000mg/m2 BD PO for 14 q21 days). 3patients received 12 weeks of preoperative 5-Flourouracil (5-FU) (300mg/m2 IVI per day for 12 weeks) and Mitomycin C(MMC) (7mg/m2 IV bolus q 6 weeks) prior to CRT. 1 patient was treated with Capecitabine (1250mg/m2 BD PO for 14 daysq21 days) and MMC (as above).13 patients received concomitant chemotherapy, 10 with Capecitabine (825mg/m2 BD PO daily) and 2 with intravenous 5-FU(200mg/m2 daily IVI and 300 mg/m2 weekly bolus). 2 patients required a 25% dose reduction of Capecitabine. Adjuvantchemotherapy protocols were well tolerated.All but 1 patient underwent R0 resection. 9 patients (52.9%) were downstaged (reduction in AJCC stage). 6 patients (35.3%)achieved a complete pathological response. No patient required a gap in treatment. Only 2 patients suffered grade III acutetoxicity and none grade IV (RTOG). There were 3 grade III and 3 grade IV late non-haematological toxicities (Lent-Soma).Omitting cutaneous and haematological toxicity, there was no acute toxicity recorded in 5 patients.

Conclusions: High rectal, recto-sigmoid and distal sigmoid tumours have not been accurately identified and reported in a trialto date. Our data suggests that such high-risk locally advanced tumours may be treated with pre-operative CRT with acceptabletoxicity and impressive down-staging, rendering clear surgical margins in most patients, with an excellent short term outcome.

Author Disclosure: B.D.P. O’Neill, None; G. Brown, None; D.M. Tait, None.

2166 Treatment of Small Hepatocellular Carcinomas With Stereotatic Body Radiation Therapy (SBRT) inPatients With Advanced Cirrhosis: A Preliminary Report

S. Song1, D. G. Maluf1, S. H. Benedict1, D. Y. Song2, E. Bump1, B. Williams1

1Virginia Commonwealth University Health System, Richmond, VA, 2Johns Hopkins University School of Medicine,Baltimore, MD

Purpose/Objective(s): Newly diagnosed hepatocellular carcinomas (HCC) in patients with advanced cirrhosis waiting for livertransplant often need bridging therapy prior to transplantation. The current standard treatments include invasive local ablationtherapy which poses high risks due to poor liver functions. This study investigates the feasibility of using SBRT for thetreatment of small HCC in patients with severe cirrhosis.

Materials/Methods: This prospective study was approved by VCU IRB with an accrual goal of 20 subjects. Written consentwas required. Eligibility criteria includes: Age� 20 but �75 years; a solitary tumor �5 cm in diameter; Child-pugh B-Ccirrhosis; AFP � 12 ng/dl; no indication for surgical resection or local ablation therapy. For treatment planning, simulation CTscan was performed with contrast enhancement. If the tumor was not well visualized, the CT images would be fused with liverMRI images to facilitate accurate delineation of tumor. Clinical target volume (CTV) included gross tumor volume (GTV) plus10 mm margin, which was expanded by 5–8 mm to create planning target volume (PTV). A total dose of 30–45 Gy wasdelivered to PTV in 3 fractions over a period of 1 week, using SBRT with 6 and 18 MV photon beams. The prescribed dosewould not exceed a 20% risk of radiation-induced liver disease (RILD) based on Lyman normal tissue complication model forpatients without liver disease.

S302 I. J. Radiation Oncology ● Biology ● Physics Volume 66, Number 3, Supplement, 2006

Results: Six patients have been enrolled and treated according to the protocol; 3 females and 3 males, ages 50–75 years. Allwere diagnosed with Child-pugh B and C cirrhosis, 4 of the patients presented with moderate to large amount but stable ascites.Primary diseases include HCV (3), HBV (1), cryptogenic (1) and alcoholic (1) hepatitis. The average tumor size was 2.0(1.6–2.5) cm. The mean pretreatment AFP was 4384 (23–8123) ng/dl. Four patients received 30 Gy, 2 patients received 42 Gy.Only one patient developed nausea and vomiting after the first treatment and no recurrent nausea and vomiting following thesecond and third treatments. No major or minor complications were reported in the other 5 patients. At three-month’ follow-up,a liver MRI showed a loss of gadolinium enhancement in all patients and a decrease in AFP from four- to 20-fold and continuingto decrease. In one patient who was followed up to 7 months, her AFP had decreased remarkably from initial 8123 ng/dl to 2.8ng/dl. One patient received post-treatment liver transplant at 9 months, explanted liver showed complete necrosis of the targetedlesion, consistent with local ablation therapy.

Conclusions: SBRT is well tolerated and appears to be safe and effective for the treatment of HCC in severely cirrhotic patients.It should be considered for solitary HCC in the patients with advanced cirrhosis when local ablation therapy is not feasible dueto high risks of the invasive procedures. However, these results are preliminary experiences from a small number of patients.A large prospective cohort of patients with longer follow-up is needed to confirm this result. Selection criteria and treatmentdose also needs to be further defined in this patient population.

Author Disclosure: S. Song, None; D.G. Maluf, None; S.H. Benedict, None; D.Y. Song, None; E. Bump, None; B. Williams,None.

2167 Repeated Proton Beam Therapy for Previously Irradiated Hepatocellular Carcinoma - Dose-VolumeHistogram (DVH) Analysis

T. Hashimoto1,2, K. Tokuuye1, K. Ohnishi3, N. Fukumitsu1, M. Hata1, S. Sugahara4, K. Ohara4, E. Tohno5, T. Nishimura2,Y. Akine1

1Proton Medical Research Center, University of Tsukuba, Tsukuba, Japan, 2Division of Radiation Oncology, ShizuokaCancer Center Hospital, Shizuoka, Japan, 3Tsukuba University Hospital, Tsukuba, Japan, 4Department of RadiationOncology, University of Tsukuba, Tsukuba, Japan, 5Department of Radiology, University of Tsukuba, Tsukuba, Japan

Purpose/Objective(s): To determine the tolerance dose of proton irradiation to the limited volume of the liver, we retrospec-tively reviewed patients having hepatocellular carcinoma (HCC) treated with repeated proton beam therapy, whose clinicaltarget volume (CTV) was overlapped with a part of the liver previously irradiated.

Materials/Methods: From September 2001 through December 2005, 219 patients with HCC underwent their first course ofproton beam therapy at the University of Tsukuba. Of the 219 patients, 28 underwent 2 or more courses of proton beam therapy.Of the 28 patients, 17 (61%) had CTVs overlapping with previously irradiated volumes in the peripheral region of liver. Thedose-volume relationship for the 17 patients was examined using the DVH analysis. Median interval between the first and thesecond course was 13 months. Median total doses for the first course and the second course of proton beam therapy were 66Gy in 22 fractions and 60 Gy in 10 fractions, respectively.

Results: Median total dose for the overlapped CTVs was equivalent to 154 Gy for 2 Gy per fraction when a linear quadraticmodel with �/� ratio of 3 was used in converting given doses with the different fractionation regimens. Median non-cancerousliver volume to which 100 Gy or more was delivered was 28 ml. Median non-irradiated liver volume was 654 ml. There wasno patient who had treatment-related liver toxicity of grade III or more.

Conclusions: Repeated proton irradiation with high dose for HCC is safe even if the CTV is overlapped with the previouslyirradiated CTV, when the CTVs are located in the peripheral region of the liver. Treatment planning should be performedemphasizing to increase the non-irradiated liver volume and less emphasizing to decrease the overlapped volume.

Author Disclosure: T. Hashimoto, None; K. Tokuuye, None; K. Ohnishi, None; N. Fukumitsu, None; M. Hata, None; S.Sugahara, None; K. Ohara, None; E. Tohno, None; T. Nishimura, None; Y. Akine, None.

2168 Adjuvant 5-FU/cisplatin and Chemoradiation With Capecitabine After Radical Gastrectomy forAdvanced Gastric Cancer

H. Lee, Y. Choi, W. Hur, H. Kwon, M. Kim, G. Jung

Dong-A University Hospital, Pusan, Republic of Korea

Background: INT-0116 study established a new standard care for patients following curative resection of gastric cancer.However, the principal benefit associated with postoperative chemoradiation after radical operation (D2 lymphadenectomy) foradvanced gastric cancer (stage III-IVM0) were less pronounced.

Purpose/Objective(s): To evaluate the efficacy and toxicity of adjuvant 5-FU/cisplatin and chemoradiation with capecitabineafter radical gastrectomy for advanced gastric cancer.

Materials/Methods: Forty patients who had underwent a radical gastrectomy (D2 lymphadenectomy) for Stage III and IV (M0)gastric cancer were enrolled. Therapy consists of one cycle of FP (continuous infusion of 5-FU 1000 mg/m2 on day 1�5 andcisplatin 60 mg/m2 on day 1) followed by 4500 cGy (180 cGy/d) with capecitabine (1650 mg/m2/d throughout radiotherapy).Four weeks after completion of the radiotherapy, patients received three additional cycles of FP every three weeks. The medianfollow-up duration was 25 months.

Results: The 3-year disease free and overall survival in this study were 65.4% and 82.1%, respectively. Eight patients (20%)showed relapse during follow-up. Eight patients did not complete all planned adjuvant therapy. Grade 3/4 toxicities includedneurtopenia in 45%, anemia in 15%, thrombocytopenia in 2.5%, nausea/vomiting in 5% and adhesive ileus requiring operationin 5%. Neither grade 3/4 hand foot syndrome nor treatment related febrile neutropenia or death were observed.

S303Proceedings of the 48th Annual ASTRO Meeting