Panchatattva is Sanskrit for "Five Truths" or "Five Elements". Many different Hindu, Tantric and Buddhist traditions have different understanding of this term.
Panchatattva as cognate with Ganachakra and Panchamakara
Arthur Avalon (1918) affirms that the Five Nectars of Tantra, Hindu and Buddhist traditions are directly related to the Mahābhūta or Five Elements and that the Panchamakara is actually a vulgar term for the Panchatattva and affirms that this is cognate with Ganapuja:
Worship with the Pañcatattva generally takes place in a Cakra or circle composed of men and women, Sadhakas and Sadhikas, Bhairavas and Bhairavis sitting in a circle, the Shakti being on the Sadhaka's left. Hence it is called Cakrapuja. A Lord of the Cakra (Cakreshvara) presides sitting with his Shakti in the center. During the Cakra, there is no distinction of caste, but Pashus of any caste are excluded. There are various kinds of Cakra -- productive, it is said, of differing fruits for the participator therein. As amongst Tantrik Sadhakas we come across the high, the low, and mere pretenders, so the Cakras vary in their characteristics from say the Tattva-cakra for the Brahma-kaulas, and the Bhairavi-cakra (as described in Mahanirvana, VII. 153) in which, in lieu of wine, the householder fakes milk, sugar and honey (Madhura-traya), and in lieu of sexual union does meditation upon the Lotus Feet of the Divine Mother with Mantra, to Cakras the ritual of which will not be approved such as Cudacakra, Anandabhuvana-yoga and others referred to later.
"Cakrapuja" is cognate with Ganachakra or Ganachakrapuja.