Key words: tomotherapy, TomoDi- rect, breast cancer, brain metastasis, bone metastasis. Disclosure: The authors have no con- flicts of interest to disclose. Correspondence to: Pierfrancesco Franco, Radiation Oncology Depar- tment, Tomotherapy Unit, Ospedale Regionale “U. Parini”, Viale Ginevra 3, 11100 Aosta, Italy. Tel +39-0165-543420; fax +39-0165-543421; e-mail pfranco@ausl.vda.it Received August 30, 2010; accepted February 3, 2011. TomoDirect: an efficient means to deliver radiation at static angles with tomotherapy Pierfrancesco Franco 1 , Paola Catuzzo 2 , Domenico Cante 1,6 , Maria Rosa La Porta 1,6 , Piera Sciacero 1,6 , Giuseppe Girelli 1,6 , Valeria Casanova Borca 2,7 , Massimo Pasquino 2,7 , Gianmauro Numico 3 , Santi Tofani 2,7 , Teodoro Meloni 4 , Umberto Ricardi 5 , and Franca Ozzello 1,6 1 Radiation Oncology Department, Tomotherapy Unit, 2 Medical Physics Department, 3 Medical Oncology Department, and 4 Diagnostic and Interventional Radiology Department, Ospedale Regionale “U. Parini”, AUSL Valle d’Aosta, Aosta; 5 Department of Medical and Surgical Sciences, Radiation Oncology Unit, University of Turin, Ospedale San Giovanni Battista, Turin, Italy; 6 Radiotherapy Department, 7 Medical Physics Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy ABSTRACT Aims and background. TheTomoTherapy Hi-Art II system is able to deliver dynamic intensity-modulated radiation therapy within a helical geometry providing robust conformality and modulation, abrupt dose falloff, and reliable accuracy. A new up- grade namedTomoDirect was introduced recently, allowing delivery of radiation at discrete angles with a fixed gantry. We present our preliminary clinical experience withTomoDirect. Methods. Three specific clinical contexts were chosen for the implementation ofTo- moDirect, namely palliation of bone metastasis pain (BP), whole brain radiation ther- apy for intracranial secondary lesions (WBRT), and adjuvant whole breast radiation therapy after conservative surgery for early stage breast cancer (AWBRT). After ap- propriate positioning, planning CT, contouring, and plan generation, all patients were treated with theTomoDirect upgrade of theTomoTherapy Hi-Art II system with different doses and fractionation according to clinical decision-making. Results. Between May and December 2010, 41 patients were treated withTomoDirect. Eighteen patients were treated for BP (mainly vertebral metastases) with a predomi- nant posterior field arrangement. Seven patients were treated for WBRT (multiple brain lesions) with a parallel-opposed latero-lateral approach and 16 patients were treated for conventionally fractionated AWBRT mainly with a 2-field tangential ap- proach. Radiation treatments were generally well tolerated and the acute toxicity was mild. Conclusions. While helical tomotherapy allows the delivery of very sophisticated treatment plans, in certain anatomical sites and clinical contexts where the number ofbeamdirectionsisconstrainedandsupposednottoaffectplanquality,TomoDirect might be an efficient means to deliver radiation at static angles with consistent dosi- metric and clinical results. Introduction In recent years there has been significant progress in radiation therapy dose deliv- ery with the implementation of 3D conformal radiotherapy (3DCRT) and intensity- modulated radiation therapy (IMRT), leading to substantial improvements in cancer treatment in terms of tumor control rate and sparing of normal tissues 1 . More re- cently, image-guided radiotherapy (IGRT) substantially increased the ballistic preci- sion of radiotherapy, minimizing setup and organ motion uncertainties 2 . The To- moTherapy Hi-Art II system (TomoTherapy Inc, Madison,WI, USA) is a radiation de- livery platform that combines the possibility to deliver dynamic IMRT within a heli- Tumori, 97: 498-502, 2011