Radiation treatment with volumetric modulated arc therapy of hepatocellular carcinoma patients. Early clinical outcome and toxicity profile from a retrospective analysis of 138 patients

Background. Treatment of pelvic lymph nodes (PLNs) in higher risk prostate carcinoma is controversial. The primary focus of the study was to evaluate the early toxicity profile for this cohort of patients treated with Volumetric Modulated Arc Therapy (VMAT).Methods. Patient, tumour, and treatment characteristics of those who received VMAT from May 2010 to December 2012 were analysed. A simplified contouring process of the PLNs to the aortic bifurcation was developed based on consensus guidelines. Acute and late genitourinary (GU) and gastrointestinal (GI) toxicities were documented according to the Radiation Therapy Oncology Group (RTOG) Version 2 Guidelines. Successive Prostate Specific Antigen (PSA) values after treatment were measured on average 3 months apart.Results. 113 patients were treated between May 2010 to December 2012 with a median follow-up of 14 months. No patients experienced acute grade 3 or 4 GU and GI toxicity. Only 1 patient experienced a late grade 3 GU complication. No late grade 4 GU or GI events have yet occurred.Conclusions. This study reviews the first Australian experience of VMAT in the treatment of pelvic lymph nodes in prostate cancer, specifically to the level of the aortic bifurcation. It demonstrates a favorable acute toxicity profile whilst treating large PLN volumes with optimal dose coverage.

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Stereotactic radiation treatment planning with volumetric modulated arc therapy: Impact of duodenal sparing on pancreatic tumor coverage.

Journal of Clinical Oncology ◽

10.1200/jco.2011.29.4_suppl.301 ◽

2011 ◽

Vol 29 (4_suppl) ◽

pp. 301-301

Author(s):

R. Kumar ◽

J. Kang ◽

J. M. Herman ◽

R. Tuli ◽

T. M. Pawlik ◽

...

Keyword(s):

Pancreatic Cancer ◽

Treatment Planning ◽

Radiation Treatment ◽

Volumetric Modulated Arc Therapy ◽

High Dose ◽

Stereotactic Radiation ◽

Radiation Delivery ◽

Delivery Times ◽

Arc Therapy ◽

The Difference

301 Background: Volumetric modulated arc therapy (VMAT) allows for intensity-modulated radiation delivery with faster treatment times and fewer delivered monitor units (MU). The dose-limiting structure for pancreatic stereotactic body radiation therapy (SBRT) is the duodenum. We evaluate VMAT dose distribution, delivery times, and the effect of duodenal sparing (DS) for pancreas SBRT. Methods: Plans of 15 patients with unresectable pancreatic cancer (14 head/1 tail) were selected. VMAT treatment planning with the “SmartArc” function of Pinnacle v. 8.9 was used to plan one fraction of 25 Gy to the PTV (gross tumor + 2 mm expansion) normalized to the 80% isodose line. Two VMAT SBRT plans were conducted for each case; the first did not attempt to spare the duodenum (non DS) while the second did (DS). Constraints were stomach/duodenum any point max <30 Gy (for DS plan), liver D50 < 5 Gy, ipsilateral kidney D25 < 5 Gy, cord Dmax < 5 Gy and stomach D4 < 22.5 Gy. Results: Gross tumor volume ranged from 58.4cm3 to 320.3 cm3. The average overlap volume between PTV and the duodenum was 8.4 cm3. In 10/15 non-DS plans, the duodenal Dmax exceeded 30 Gy. With DS optimization, only 1/15 plans exceeded the 30 Gy threshold. These differences were statistically significant (p<0.001). Typical MU and delivery times, as calculated by the planning software, were 5494 MU and 775 secs vs. 5296 MU and 703 secs for the DS and non-DS plans, respectively. The difference in delivery times was significant (p=0.01), but amounted to only 1.2 min on average. The average duodenal Dmax for non-DS plans was 30.4Gy, D4% was 23.4 Gy. With DS, the average Dmax was reduced to 28.1Gy and D4% to <19.7 Gy (p<0.001). As expected, VMAT plans with greater overlap between the duodenum and PTV had a higher duodenal Dmax. Conclusions: This study demonstrates the feasibility of VMAT for high-dose SBRT treatment of pancreatic cancer incorporating constraints to limit the dose to the duodenum. Future studies will evaluate whether VMAT with fractionated SBRT results in improved duodenal sparing more efficiently than traditional IMRT. No significant financial relationships to disclose.

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