Volumetric modulated arc therapy versus step‐and‐shoot intensity modulated radiation therapy in the treatment of large nerve perineural spread to the skull base: a comparative dosimetric planning study
| Autor: | Rhys Fitzgerald, Tamara Barry, Peter Gorayski, Elizabeth Burmeister, Matthew Foote |
|---|---|
| Rok vydání: | 2014 |
| Předmět: |
squamous cell carcinoma
Step and shoot Base of skull Radiological and Ultrasound Technology business.industry skin neoplasms medicine.medical_treatment Original Articles Intensity-modulated radiation therapy Volumetric modulated arc therapy intensity modulated radiation therapy Radiation therapy Skull medicine.anatomical_structure Planning study Perineural spread cranial nerve diseases Medicine Radiology Nuclear Medicine and imaging business Nuclear medicine |
| Zdroj: | Journal of Medical Radiation Sciences |
| ISSN: | 2051-3909 2051-3895 |
| DOI: | 10.1002/jmrs.45 |
| Popis: | Introduction: Cutaneous squamous cell carcinoma with large nerve perineural (LNPN) infiltration of the base of skull is a radiotherapeutic challenge given the complex target volumes to nearby organs at risk (OAR). A comparative planning study was undertaken to evaluate dosimetric differences between volumetric modulated arc therapy (VMAT) versus intensity modulated radiation therapy (IMRT) in the treatment of LNPN. Methods: Five consecutive patients previously treated with IMRT for LNPN were selected. VMAT plans were generated for each case using the same planning target volumes (PTV), dose prescriptions and OAR constraints as IMRT. Comparative parameters used to assess target volume coverage, conformity and homogeneity included V95 of the PTV (volume encompassed by the 95% isodose), conformity index (CI) and homogeneity index (HI). In addition, OAR maximum point doses, V20, V30, non-target tissue (NTT) point max doses, NTT volume above reference dose, monitor units (MU) were compared. Results: IMRT and VMAT plans generated were comparable for CI (P = 0.12) and HI (P = 0.89). VMAT plans achieved better V95 (P = < 0.001) and reduced V20 and V30 by 652 cubic centimetres (cc) (28.5%) and 425.7 cc (29.1%), respectively. VMAT increased MU delivered by 18% without a corresponding increase in NTT dose. Conclusion: Compared with IMRT plans for LNPN, VMAT achieved comparable HI and CI. |
| Databáze: | OpenAIRE |
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