2 great options for you

SELECT * FROM gallery2 WHERE topic_id="763581" UNION SELECT * FROM gallery2 WHERE topic_id="120594" UNION SELECT * FROM gallery2 WHERE topic_id="804632" UNION SELECT * FROM gallery2 WHERE topic_id="1412373" UNION SELECT * FROM gallery2 WHERE topic_id="863999" UNION SELECT * FROM gallery2 WHERE topic_id="1581414" UNION SELECT * FROM gallery2 WHERE topic_id="635792" UNION SELECT * FROM gallery2 WHERE topic_id="1461502" UNION SELECT * FROM gallery2 WHERE topic_id="376039" UNION SELECT * FROM gallery2 WHERE topic_id="1663138" UNION SELECT * FROM gallery2 WHERE topic_id="1057703" UNION SELECT * FROM gallery2 WHERE topic_id="1806491" UNION SELECT * FROM gallery2 WHERE topic_id="634239" UNION SELECT * FROM gallery2 WHERE topic_id="985354" UNION SELECT * FROM gallery2 WHERE topic_id="624022" UNION SELECT * FROM gallery2 WHERE topic_id="1168169"