Abstract

Title

Volumetric modulated arc therapy is superior to intensity modulated radiotherapy for liver sparing in stereotactic body radiotherapy for hepatocellular carcinoma

Authors

Yulia Kundel1, Yasmin Korzets2, Miriam Weinstock-Sabbah3, Assaf Moor4, Noa Gordon5, Dimitri Bragilovski4, Salomon Stemmer6, Aaron Popovtzer3, Baruch Brenner3, Eyal Fenig3, Aaron Allen3

Authors Affiliations

1Rabin medical center, Davidoff cancer center, Pethach tikva, Israel; 2rabin medical center, Davidoff cancer center, Pethach tikva, Israel; 3Rabin medical center, Davidoff cancer center, Petach tikva, Israel; 4Rabin Medical Center , Davidoff Cancer Center, Pethach tikva, Israel; 5Davidoff Cancer Center, Davidoff Cancer Center, Rabin Medical Center , Pethach tikva, Israel; 6Rabin Medical Center , Davidoff Cancer Center, Petach tikva, Israel

Purpose or Objective

The best radiotherapy delivery modality of stereotactic body radiotherapy for hepatocellular carcinoma is a matter of debate. The purpose of this retrospective study was to compare planning parameters with volumetric modulated arc therapy to static intensity modulated radiotherapy in treatment of hepatocellular carcinoma treated with stereotactic body radiotherapy

Materials and Methods

Twenty patients with localized hepatocellular carcinoma who were treated with stereotactic body radiotherapy were re-planned using two different radiation techniques: intensity modulated radiotherapy and volumetric modulated arc therapy. Patients with Child A cirrhosis received 45-54 Gy in 3 fractions and 5 patients with Child B cirrhosis received 30 Gy in 5 fractions. Planning was optimized to minimize doses to organs at risk without compromising coverage of the planning treatment volume. Volumetric modulated arc therapy and intensity modulated radiotherapy plans were compared using the conformity and homogeneity indices of the planning treatment volume, monitor units for time of treatment delivery, and other dose volume histogram metrics

Results

. The conformity index of volumetric modulated arc therapy plans were superior to those of intensity modulated radiotherapy (1.11±0.05 vs 1.18±0.06 (p <0.05). The monitor units were significantly lower for volumetric modulated arc therapy (423.78±50.65) than for intensity modulated radiotherapy (890±160.68) (p <0.01). Stomach max dose, normal liver V15 Gy, normal liver mean dose were also decreased with volumetric modulated arc therapy planning. This was achieved without increased :V30 Gy of duodenum and small bowel, 10 cc (Gy) of duodenum, mean dose of right kidney and cord max dose

Conclusion

To conclude, planning treatment volume coverage was more conformal with volumetric modulated arc therapy planning, with lower monitor units and shorter delivery time compared to intensity modulated radiotherapy in all patients. Moreover volumetric modulated arc therapy planning was more effective than intensity modulated radiotherapy planning in the sparing of normal liver and stomach.