DEF LEPPARD guitarist Vivian Campbell, whose cancer is once again in "remission," has just finished undergoing a new round of chemotherapy before receiving a stem-cell transplant later in the month.

Campbell — who before joining DEF LEPPARD in 1992 was well known for his work with DIO and WHITESNAKE — went public with his Hodgkin's lymphoma diagnosis last summer, but announced in November that he was in remission.

The term "remission" means that the symptoms of the cancer have either been eliminated or reduced. When the tumor is completely gone, doctors call it "complete remission."

However, Campbell revealed earlier in the year that the cancer had returned and he was battling the disease with a new high-tech chemo treatment.

While Campbell is undergoing stem-cell treatment, he will be unable to join his bandmates as they complete work on their new studio album. The guitarist will also be forced to miss the band's next few live appearances, including the pre-game show at the first of this year's three NFL International Series games on Sunday, September 28, when the Oakland Raiders host the Miami Dolphins; as well as shows in Las Vegas, Santa Ynez, Rancho Mirage and Temecula.

In a brand new message to fans on DEF LEPPARD's official web site, Campbell writes: "As many of you know, I've been scheduled to start a stem cell transplant and as soon as I got home from tour I began the necessary tests and preparations. I'll be admitted to hospital soon for all the yucky bits, so in the meantime I'm headed to Target to stock up on cozy pajamas, fresh underwear, and a sackful of car porn.

"Unfortunately, this means that I won't be able to perform with the band on the upcoming NFL broadcast on September 28th, nor will I be able to do the shows scheduled for October/November.

"While I can't say that I'm looking forward to the process ahead, I'm very much looking forward to what I feel will be a most successful outcome.

"Next year will be very busy for DEF LEPPARD with a new album and a world tour, and frankly, I don't think they would sound as loud without me, so I have no intention of letting the team down!

"See you all (with hair!) in 2015."