[Influence of preoperative (hyperthermic) radiochemotherapy on manometric anal sphincter function in locally advanced rectal cancer]. / Einfluss einer präoperativen (hyperthermen) Radiochemotherapie auf die manometrisch erfasste Analsphinkterfunktion beim lokal fortgeschrittenen Rektumkarzinom.

BACKGROUND AND PURPOSE: Preoperative radiochemotherapy (RCT) followed by curative surgery is a well-accepted therapeutic option in the treatment of advanced rectal cancer. Usually, the anal sphincter is located in the irradiation area of a preoperative RCT regime. The aim of this study is to evaluate the influence of preoperative RCT on anal sphincter function. PATIENTS AND METHODS: Between 1994 and 2000, 102 patients with rectal cancer stage uT3/uT4 were analyzed. All patients underwent radiotherapy with 45 Gy (5 x 1.8 Gy) including two cycles of 5-fluorouracil (5-FU)/leucovorin (folinic acid) chemotherapy. 46 patients were treated additionally with up to five sessions of locoregional hyperthermia. The sphincter function was analyzed by perfusion manometry before preoperative therapy and 4 weeks after pretreatment had been finished. For statistics, the Wilcoxon signed rank test and Mann-Whitney U-test were used (SPSS 9.0 for Windows((R))). RESULTS: The mean value of all 102 patients showed a significant reduction of the mean maximum resting pressure from 97 to 89 mmHg (p = 0.02). For the mean maximal squeeze pressure no significant difference could be shown (178 vs. 176 mmHg). For patients with distal (

Response prediction by FDG-PET after neoadjuvant radiochemotherapy and combined regional hyperthermia of rectal cancer: correlation with endorectal ultrasound and histopathology.

Accurate response assessment after neoadjuvant therapy is essential in patients with rectal cancer. The aim of this study was to assess the value of fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) in predicting response of locally advanced rectal cancer to preoperative multimodal treatment. Twenty-two consecutive patients with locally advanced (uT3/4) primary rectal cancer were entered in this prospective pilot study. FDG-PET was performed before and after neoadjuvant radiochemotherapy (RCT) with combined regional hyperthermia (RHT). Treatment consisted of external-beam radiotherapy (45 Gy), chemotherapy (folinic acid and 5-fluorouracil) and regional pelvic hyperthermia followed by curative tumour resection 6-8 weeks later. Semi-quantitative measurements (SUV) of tumour FDG uptake were made before and 2-4 weeks after completion of neoadjuvant treatment. Two patients who did not receive post-therapeutic restaging by FDG-PET were excluded from the analysis. Results were correlated with findings on endorectal ultrasound (EUS, n=17 patients) and histopathology. Histopathological evaluation of the resected tumour revealed complete response in one patient, partial response in 12 and stable disease in seven. SUV reduction in tumours was significantly greater in responders than in non-responders [60% (+/-15%) vs 30% (+/-18%), P=0.003, CI=95%). Using a minimum post-therapeutic SUV reduction of 36% to define response, FDG-PET revealed a sensitivity of 100% (EUS: 33%) and a specificity of 86% (EUS: 80%) in response prediction; the corresponding positive and negative predictive values were 93% (EUS: 80%) and 100% (EUS: 33%), respectively. FDG-PET results were statistically significant (P<0.001, CI=95%). FDG-PET has great potential in the assessment of tumour response to neoadjuvant RCT in combination with RHT and is superior to EUS for this purpose.

Restaging of locally advanced carcinoma of the rectum with MR imaging after preoperative radio-chemotherapy plus regional hyperthermia.

BACKGROUND: The restaging accuracy of MR imaging in advanced primary rectal carcinoma after preoperative radiochemotherapy and regional hyperthermia was evaluated and compared with the histopathologically verified degree of tumor remission after a course of radio-chemo-thermotherapy. PATIENTS AND METHODS: 35 patients with primary rectal carcinoma (uT3/uT4) underwent MRI using a surface coil 4-6 weeks after radiochemotherapy (n = 35), regional hyperthermia (n = 23), and before curative surgery. We defined as gold standard for the remission status the comparison of pretherapeutic endosonography with the histopathology of the resected specimen. RESULTS: T category was correctly restaged after preoperative treatment in only 19 (54%) of 35 patients. Nine of 20 responders were overstaged and seven of 15 non-responders were understaged. Concurrently, the N category was correctly restaged in 19 (54%) of 35 patients (twelve responders and seven non-responders). Overstaging occurred in four responders and two non-responders, understaging occurred in four responders and six non-responders. CONCLUSIONS: MRI proved independent of the response status as not suitable to restage locally advanced rectal carcinoma after preoperative radiochemotherapy despite optimized imaging technique and spatial resolution. Basically, imaging the morphology of a tumor cannot clearly differentiate between vital and devitalized tissue after a treatment. Functional imaging such as PET (positron emission tomography) appears more feasible for restaging after radio-chemo-thermotherapy.