Postoperative adjuvant radio(chemo)therapy for rectal cancer: an appraisal.

AIMS AND BACKGROUND: Rectal cancer can be considered a broad-spectrum disease, where the surgeon, radiation oncologist and medical oncologist have a peculiar and specific place in order to work harmoniously as a good orchestra. The reality in common general hospitals is far from that of comprehensive cancer centers, particularly for postoperative approaches. The adjuvant therapy of rectal cancer is not codified worldwide, and it is strongly dependent on preoperative staging procedures, surgeon's acts and pathologist's decisions. Starting from our 10-year experience, we analyzed the various steps of postoperative approaches, defining possible decision errors, the incongruity of some attitudes, and the lack of knowledge of recent achievements of science in this disease. METHODS: A total of 194 patients with advanced surgically removed rectal cancer (pT3-4 pN0-any pT pN+) treated with postoperative radio(chemo)therapy was reviewed retrospectively. Anterior resection was performed in 126, abdominoperineal resection in 48, and other surgical procedures in 20 patients. Irradiation was conducted with a single daily fraction of 1.8 Gy until 45 Gy, and chemotherapy consisted of the combination of 5-fluorouracil and folinic acid (Machover schedule): 47% of patients with positive nodes did not receive chemotherapy. RESULTS: Five-year overall survival was 60.6% and relapse-free survival was 55.5%. The main prognostic factors were pathological T and N stages. The principal route of progression was distant metastases. Acute toxicity was severe in 1 case (drug toxic hepatitis) and very severe in 16 patients, and late severe sequelae appeared in 13 patients. CONCLUSIONS: The outcome of rectal cancer patients has not changed during the last decade, and this was confirmed in our study. The improvement of radiotherapy techniques has reduced the adverse acute and late toxicity. The best postsurgical approach for pT3pN0 cancer remains unsolved, as the good chemotherapy combination and the real solution could be the application of a new Consensus Conference.

Visual verification of linac light and radiation fields coincidence.

X-ray and light field alignment evaluation is carried out during linac quality assurance programs. In this paper, we compare the size of the light field measured by a photodiode and by a more traditional visual observation with the size of the x-ray field. The comparison between actual light field size, measured with the photodiode, and light field size measured by human eye allow us to verify the reliability of human eye in the evaluation of this parameter. The visual field is always larger than real light field; however, it agrees better with the x-ray field. It matches the light field if we take into account the 25% (+/- 1%) of the decrement line of the maximum central lightening; however, this method simulates better the actual field employed in radiation treatments.