HAVANA (AP) -- Venezuelan President Hugo Chavez was in Cuba on Sunday to begin radiation therapy treatment one month after undergoing surgery that removed a cancerous tumor.
Chavez was met by Cuban President Raul Castro as he arrived at Havana's airport on Saturday night. Venezuelan television showed Chavez saluting as he stepped off the plane holding hands with one of his daughters, and then embracing Castro.
Chavez said before leaving Venezuela that he would start the treatments on Sunday. He has been recovering from a Feb. 26 surgery in Havana that he said removed a tumor from the same spot in his pelvic region where another tumor was extracted eight months earlier.
In Venezuela, some of Chavez's aides led his supporters in a prayer for his health Sunday morning outside the cathedral in the southwestern city of San Cristobal, and then the crowd began a pilgrimage on foot to another church.
Chavez will be in Cuba at the same time as Pope Benedict XVI, who arrives on the island on Monday after a visit to Mexico. But in his remarks on Saturday, Chavez didn't refer to the pope's upcoming visit to Havana.
After he was diagnosed with cancer in Cuba last year, Chavez underwent an initial surgery in June that removed a tumor that he said was the size of a baseball. He then had four rounds of chemotherapy and said tests showed no signs of any cancerous cells. But last month, he announced he was returning to Cuba for surgery to remove a lesion that proved to be malignant. He has described the most recent tumor as measuring about 2 centimeters (0.8 inches).
Chavez has not identified the type of cancer nor the precise location where the tumors have been removed.
The president has said the radiation treatments will last for four to five weeks and are intended to "attack any new threat." He said on Saturday that he expects to be traveling between Venezuela and Cuba during the treatments.
He said he preferred to return to Cuba for radiation therapy because that is where his cancer was first detected last year and where he has undergone surgeries since.
Chavez said he is thankful to his close allies and friends Fidel and Raul Castro for the medical care he has received. He praised Cuba's health care system as "one of the most advanced in this world, thanks to the Cuban revolution."
Chavez is running for re-election in October and vows that his illness will not get in the way of that political goal.
Last year, Chavez shaved his head during chemotherapy after his hair began falling out as a result of the treatments.
Now, as he starts radiation therapy, some of the potential side effects of the treatments include fatigue, abdominal cramping, nausea and vomiting, said Dr. Michael Pishvaian, an oncologist at Georgetown University's Lombardi Comprehensive Cancer Center who is not involved in Chavez's treatment.
The radiation is often administered for a short period each day, with breaks on weekends, Pishvaian said. "I would imagine that he probably could go about his daily activities even being a president."
Following radiation therapy, patients typically need two weeks to a month to recover from the effects of the treatment, Pishvaian said. "Then he should actually be pretty much back to normal, but will be on sort of high alert for watching to see if the cancer comes back again."