Objective of the study is to evaluate the effectiveness of adenoidectomy for children, to asses the rates of adenoidal regrowth and find out if the regrowth of adenoidal tissue affects persistent nasal symptoms post-surgery. A prospective study was carried out in the period of 2005-2007. The inclusion criteria for patients in the study were hypertrophic adenoid tissue and moderate or severe persistent nasal obstruction. One hundred and fifty children had undergone an adenoidectomy using consistent technique and visual control. Medium-term follow-up results were conducted 12-24 months (the mean follow-up period was 17.1 months) post-surgery, performing transnasal fibroscopy and completing the questionnaire. A total of 104 (69.3%) out of 150 patients polled. Children's parents answered the questions that were used for the subjective assessment of symptoms and to ascertain the history of the patient's nasal obstruction and upper respiratory tract infection prior to surgery. The age range was from 3 to 15, of which, 68 (65.3%) of them had undergone a transnasal fibroscopy. There was a significant reduction in symptoms that were displayed by children prior to the operation: there were 5.8% patients with nasal obstruction after the surgery, while incidences of upper airway infections dropped from 79.8 to 7.7% after surgery (P < 0.001). Eighty-six (82.7%) parents considered their child's well-being as "having improved" and they were "satisfied" with the results. Transnasal fibroscopy examinations identified some regrowth of adenoidal tissue in 13 cases (19.1%), with only 3 cases demonstrating adenoidal regrowth to grade 1. Adenoidal regrowth was correlative with the age of the patients (P = 0.048) and to numerous postoperative treatment with antibiotics (P = 0.032). Adenoids rarely regrow after surgery and where there were traces of adenoidal tissue, it did not manifest clinically. Nasal obstruction after the adenoidectomy is rhinogenic origin, not the cause of enlarged adenoids. Adenoidal regrowth more often occurs in children younger than five years old and in those patients who were treated postoperatively with antibiotics on numerous occasions.

With our data we confirmed our hypothesis of postradiogenic constitutive activation of the 2 pathways both required for Ras-mediated radioresistance in epithelial cells. If this effect should prove itself as a general mechanism in Ras-mutated tumors, application of specific inhibitors to block both cascades in parallel could contribute to enhance radiosensitivity in these types of cancer.

Our data show that irradiation-induced ROS activate the MAPK pathway and release of VEGF. As VEGF is known to be released after cellular distress resulting in cytoprotection, the described mechanism is potentially of importance for therapy success.