Volumes of collections of essays which are entirely about the Pastorals (in whole or in part) are not common. Until a year or so ago, I was only aware of six:
Bieringer, Reimund, ed. 2 Timothy and Titus Reconsidered / Der 2. Timotheus- und der Titusbrief in neuem Licht. Colloquium Oecumenicum Paulinum 20. Leuven: Peeters, 2018.