REVERE-School Superintendent Paul Dakin said parental demand for Rumney Marsh sixth grade seats underscores the need to reexamine how the city’s three middle schools are organized.Dakin plans to ask School Committee members, possibly at tonight’s meeting, to discuss scrapping the theme concept for middle schools and replace it with a geographic organization plan.With two new middle schools built since 2006, fifth grade parents have been attracted to newly-opened schools rather than each school’s theme.?Parents seem to be looking for what is the freshest, cleanest building,” Dakin said, noting that parents of 180 fifth graders want to send their child to Rumney while initial sixth grade enrollment stands at 150 students for Susan Anthony School and 100 for Garfield.?We have to try to balance out at 150. How to do it is difficult,” he said.Under the current system, school officials urge fifth grade parents to pick a middle school for their child based on interest areas with Rumney Marsh Academy oriented to communications, Susan Anthony focused on arts studies and Garfield Middle School oriented to technology.Rumney’s popularity mirrors parental interest in the school a year ago when 190 parents of fifth graders sought 160 sixth grade seats available in Rumney. School officials organized a lottery to fill the seats similar to one organized in 2007 when 140 seats were up for grabs in Anthony. Requests from Paul Revere, Lincoln and Whelan parents exceeded the number available.Dakin said stiff competition for middle school seats underscores the decision the committee needs to make.?I’ll tell the School Committee it’s either struggle to make a lottery fair or present a neighborhood middle school plan,” Dakin said adding he is prepared to acknowledge that theme schools “haven’t taken hold.”Under a neighborhood plan, East Revere fifth graders would enter Garfield; West Revere fifth graders would attend Anthony and fifth graders living in the city’s central neighborhoods would attend Rumney.?We may have to honestly think about that,” Dakin said.The superintendent knows how parents vying for their child?s middle school of choice feel: His son was required to attend Beachmont for a year when the district-wide system was introduced in 1991 rather than the family?s school of choice.