I think it fits perfectly

SELECT * FROM gallery2 WHERE topic_id="916894" UNION SELECT * FROM gallery2 WHERE topic_id="1021309" UNION SELECT * FROM gallery2 WHERE topic_id="502775" UNION SELECT * FROM gallery2 WHERE topic_id="938648" UNION SELECT * FROM gallery2 WHERE topic_id="458990" UNION SELECT * FROM gallery2 WHERE topic_id="159289" UNION SELECT * FROM gallery2 WHERE topic_id="1438457" UNION SELECT * FROM gallery2 WHERE topic_id="1003836" UNION SELECT * FROM gallery2 WHERE topic_id="1024745" UNION SELECT * FROM gallery2 WHERE topic_id="1322309" UNION SELECT * FROM gallery2 WHERE topic_id="252442" UNION SELECT * FROM gallery2 WHERE topic_id="343705" UNION SELECT * FROM gallery2 WHERE topic_id="1277408" UNION SELECT * FROM gallery2 WHERE topic_id="1538274" UNION SELECT * FROM gallery2 WHERE topic_id="19406" UNION SELECT * FROM gallery2 WHERE topic_id="1782446"