In our document we have mantained the unity of this nodal group, fully included in level II (we set the posterior limit of this level at 1 cm behind the posterior wall of IJV); we accept that level V reaches cranially the mastoid, but at this most cranial level it includes a very limited and posterior area just beneath the posterior portion of the sternocleidomastoid muscle. Again, we have verified the practical value of this choice. For instance, recommending treatment of our level IIb (but not of level V) in T3 N0 larynx cancers, upper jugular nodes will be fully included but higher posterior nodes will be excluded; on the other hand, in posterior pharyngeal wall primaries both level II and V will be treated. 3. Caudal limit of level IV IC guidelines set the caudal limit of level IV at 2 cm higher than the sterno-clavicular joint. However, indepen- dently from the attitudes of head and neck surgeons, there is no reason why the lowest jugular nodes (within 2 cm from the sterno-clavicular joint) should not be considered at risk from involvement in case of a T2 N0 hypopharyngeal cancer or a subglottic carcinoma (just to mention two examples). In our document we have therefore mantained the traditional limit of low jugular nodes, i.e. the top edge of the sternum. 4. Conclusion In conclusion, the IC guidelines are a valuable tool in translating surgical criteria into radiological criteria for the delineation of neck nodal regions on axial images of the clinically negative neck. However, in the clinical practice of radiation oncology, some further refinements appear to be justified to make these criteria useful in a wider range of clinical presentations. References [1] Gre ´goire V, Levendag P, Ang KK, et al. CT-based delineation of lymph node levels and related CTVs in the node-negative neck: DAHANCA, EORTC, GORTEC, NCIC, RTOG consensus guidelines. Radiother Oncol 2003;69:227–36. [2] Palazzi M, Soatti C, Bianchi E, et al. Guidelines for the delineation of nodal regions of the head and neck on axial computed tomography images. Tumori 2002;88:355–60. Mauro Palazzi a, *, Barbara A. Jereczeck-Fossa b , Carlo Soatti c , on behalf of the AIRO-Lombardia Head and Neck Working Party a Unit of Radiotherapy, Istituto Nazionale Tumori, Via Venezian 1, 20133 Milan, Italy b Division of Radiotherapy, European Institute of Oncology, Milan, Italy c Unit of Radiotherapy, Ospedale A. Manzoni, Lecco, Italy *Corresponding author. 0167-8140/$ - see front matter q 2004 Published by Elsevier Ireland Ltd. doi:10.1016/j.radonc.2004.07.024 Received 19 July 2004 Reply to the letter to the editor from Palazzi et al. Dear Sir We read with much interest the comments from Palazzi et al. regarding our recent manuscript on ‘CT- based delineation of lymph node levels and related CTVs in the node negative neck: DAHANCA, EORTC, GORTEC, NCIC, RTOG consensus guidelines [1]. The guidelines presented in this manuscript resulted from a consensus obtained among the relevant major European and North American cooperative groups. It is however obvious that neck node delineation is an evolving issue, and every comment/criticism that could potentially help improving our proposal are welcome. In that regards, we are thankful to Palazzi et al. for their efforts to comment on our manuscript. Before addressing one by one the various com- ments of Palazzi et al. we would like to reiterate the spirit in which the panel of experts elaborated these guidelines. † The guidelines did not intend to give any recommen- dation on the treatment policy for the node negative neck, e.g. observation versus prophylactic treatment, surgery versus radiation, elective versus extensive treatment. The guidelines had the sole intention of providing unequivocal, international agreed upon, consensus recommendations on how to delineate the various neck nodal levels on CT. † The proposed guidelines only addressed the node negative neck. For the node positive neck and in case of post-operative irradiation, adjustments still have to be made. Preliminary suggestions have already been discussed in our manuscript. Tentative recommen- dations will be discussed at upcoming ESTRO and ASTRO meetings. † The panel of experts agreed on the methodology, e.g. to transpose (and when necessary translate) the surgical nomenclatures and procedures to the world of radiation oncology. The various reasons that Letters to the Editor / Radiotherapy and Oncology 73 (2004) 383–386 384