Given the task definition and input, reply with output. Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

The aim of this study is to evaluate if it is necessary to remove all the radioactive sentinel lymph nodes (SLNs) not seen on lymphoscintigraphy in order to accurately stage breast cancer patients.', 'From March 1999 to March 2006, SLN biopsy was performed in 461 patients. All patients were only injected with radioisotope. Lymphoscintigraphy was performed in all the patients. The mean number of SLNs removed was 2.1 (range 1-15).', 'The SLN was positive in 133 patients (28.8%). Lymphoscintigraphy accurately predicted the number of SLNs identified intraoperatively in 243 patients (52.7%). In 175 patients (37.9%) there were more SLNs identified intraoperatively than were seen on lymphos cintigraphy. In 11 (6.2%) of these 175 patients, additional SLNs identified intraoperatively harboured metastasis. Type of injection, need for a second injection, tumour location and age were not identified as statistically significantly associated with additional positive SLNs identified intraoperatively and not seen on lymphoscintigraphy.
Does removal of all radioactive sentinel nodes in breast cancer improve the detection of positive sentinel nodes?