The following typoscript, will replace the text in the <title> tag with the category corresponding to the tx_ttnews[cat] url parameter.

# Make the title the same as the tt_news title #

config.noPageTitle = 1

temp.newsTitle = COA

temp.newsTitle {

10 = RECORDS

10 {

  source = {GPvar:tx_ttnews|cat}

  source.insertData = 1

  tables = tt_news_cat

  conf.tt_news_cat >

  conf.tt_news_cat = TEXT

  conf.tt_news_cat.field = title

}

}

temp.newsTitle.wrap = <title>|</title>

page.headerData.10 < temp.newsTitle

Also, you may find it necessary sometimes to include a condition so that the above code only gets called if the parameter tx_ttnews|cat is present. You would modify the above typoscript snippet slightly as follows.

[globalVar = GP:tx_ttnews|cat > 0]

# Make the title the same as the tt_news title #

config.noPageTitle = 1

temp.newsTitle = COA

temp.newsTitle {

10 = RECORDS

10 {

  source = {GPvar:tx_ttnews|cat}

  source.insertData = 1

  tables = tt_news_cat

  conf.tt_news_cat >

  conf.tt_news_cat = TEXT

  conf.tt_news_cat.field = title

}

}

temp.newsTitle.wrap = <title>|</title>

page.headerData.10 < temp.newsTitle

[global]