How useful is rectal endosonography in the staging of rectal cancer?

It is essential in treating rectal cancer to have adequate preoperative imaging,as accurate staging can influence the management strategy,type of resection,and candidacy for neoadjuvant therapy.In the last twenty years,endorectal ultrasound(ERUS) has become the primary method for locoregional staging of rectal cancer.ERUS is the most accurate modality for assessing local depth of invasion of rectal carcinoma into the rectal wall layers(T stage) .Lower accuracy for T2 tumors is commonly reported,which could lead to sonographic overstaging of T3 tumors following preoperative therapy.Unfortunately,ERUS is not as good for predicting nodal metastases as it is for tumor depth,which could be related to the unclear definition of nodal metastases.The use of multiple criteria might improve accuracy.Failure to evaluate nodal status could lead to inadequate surgical resection.ERUS can accurately distinguish early cancers from advanced ones,with a high detection rate of residual carcinoma in the rectal wall.ERUS is also useful for detection of local recurrence at the anastomosis site,which might require fine-needle aspiration of the tissue.Overstaging is more frequent than understaging,mostly due to inflammatory changes.Limitations of ERUS are operator and experiencedependency,limited tolerance of patients,and limited range of depth of the transducer.The ERUS technique requires a learning curve for orientation and identification of images and planes.With sufficient time and effort,quality and accuracy of the ERUS procedure could be improved.

DETECTION OF OCCULT TUMOR CELLS IN RESECTED LYMPH NODES OF PATIENTS WITH STAGE I CARCINOMA AND ITS CLINICOPATHOLOGICAL SIGNIFICANCE

Objective: A lot of 3715 resected lymph nodes from 350 stage I cancer patients, including 94 NSCLC, 112 breast carcinoma, 115 esophageal carcinoma, and 29 vulvar carcinoma cases, were re examined by immuno histochemistry. Methods: Using monoclonal anti cytokeratins (AE1/AE3), anti EMA, and polyclonal anti keratin antibodies, the tumor cell micrometastases were detected to obtain more reliable information concerning the nodal status. Results: Nodal occult metastases were observed in 113 of 350 (32.5%) patients and in 203 of 3715 (5.5%) nodes. The positive rates in both patients and nodes were higher in NSCLC than in others (P<0.05). The nodal occult metastases were seen in 58% of pulmonary squamous cell carcinoma and 53.8% of adenocarcinoma, while they were seen in 22.5% of esophageal and 10.3% of vulvar squamous cell carcinomas and in 27.7% of breast adenocarcinoma (P<0.05). Follow up of a part of breast carcinoma patients showed that the clinical prognosis was worse in patients with positive nodes than in negative ones (P< 0.05 ). Conclusion: The data suggested that the immunohistochemical techniques can significantly facilitate the detection of micrometastatic tumor cells in lymph nodes. The frequency of nodal occult metastases may have important impact on the clinical prognosis of cancer patients.

^(18)F-FDG-PET/CT-guided radiotherapy of cervical lymph nodes in head and neck squamous cell carcinoma

The use of positron emission tomography with fluor-18-fluorodeoxyglucose(FDG-PET)in clinical practice for patients with head and neck squamous cell carcinoma(HNSCC)has expanded rapidly,with implications for diagnostic staging,radiotherapy planning,adaptive radiotherapy,and post-therapy evaluation.The implementation of FDG-PET/CT in radiation treatment planning not only has consequences for target volume definition and dose prescription but is also associated with an increased overall survival in patients with HNSCC.FDG-PET/CT-guided gradient dose prescription provides a window of opportunity for treatment de-intensification of the neck in order to decrease treatment-related toxicity without compromising oncological outcome.Further,interim FDG-PET/CT during radiotherapy can be useful to assess metabolic tumor response and enables opportunities for adaptive treatment strategies.The goals are to increase treatment effectivity in poor responders and reduce unnecessary toxicity in patients with good early tumor response.Further prospective trials investigating adaptive radiotherapy based on interim PET-evaluation are needed,especially regarding human papilloma virus-negative HNSCC and patients treated with primary radiotherapy.