Dr. Moody D. Wharam Jr., a pioneering Johns Hopkins Hospital radiation oncologist whose life’s work focused on helping children stricken with cancers, died Aug. 10 from amyotrophic lateral sclerosis, commonly known as Lou Gehrig’s disease, at Franklin Square Medical Center. He was 77.

“He was an incredibly smart, gracious and dignified man who absolutely changed how children are treated for cancer,” said Dr. Theodore L. DeWeese, chairman of radiation oncology and molecular radiation science at the Johns Hopkins Hospital. “He brought attention to detail, a caring touch, and research that reminds us that we’re here to help patients and we’re never to forget that.

Dr. Curt Civin, associate dean for research at the University of Maryland School of Medicine and former director of pediatric oncology at Hopkins’ Kimmel Cancer Center, said in a Hopkins press release: “For literally thousands of our own pediatric oncology patients and in nationally and internationally impactful clinical trials in childhood cancers, Dr. Moody Wharam served for decades as a rock of unswerving clinical excellence, caring and progress.”

Moody DeWitt Wharam Jr., was the son of Moody DeWitt Wharam Sr., an insurance agent, and Ethyl Morris Wharam, an executive secretary to the Secretary for Trust Territories at the U.S. Department of the Interior. He was born in Washington and raised in Arlington, Va. After graduating from Washington-Lee High School in Arlington, he received a bachelor’s degree in economics in 1963 from Harvard University. He then served as a naval officer assigned to shipboard duty as part of the Navy’s Atlantic Fleet from 1963 to 1965.

He received his medical degree in 1969 from the University of Virginia School of Medicine and completed an internship in medicine and pediatrics at Washington’s Georgetown University Medical Center. From 1970 to 1973, he held a fellowship in radiation therapy from the National Institutes of Health and conducted it at the University of California Medical Center in San Francisco. He joined the faculty of Duke University Medical School in 1974, then a year later was the second person recruited to join the new Johns Hopkins Hospital Division of Radiation Oncology in its cancer center, now the Sidney Kimmel Comprehensive Cancer Center.

Dr. Wharam’s primary clinical and academic focus was childhood cancers. At the time he arrived at Hopkins, only 50 percent of children diagnosed with cancer survived. “We were having great success in certain cancers, so we had to see if we could back off in the amount of radiation we were giving these patients. At the same time kids were still dying, so we also had to figure out how we could do a better job of treating them,” he said in a 2017 interview with On Target, a publication of the Kimmel Cancer Center. “Knowing that the therapies we give children for their cancers could cause other problems for them was one of the most difficult aspects of our job.”

From 1980 to 1990, he served as chairman of the radiation oncology committee of the Pediatric Oncology Group, a National Cancer Institute collaborative whose mission was studying childhood cancer. A biographic profile noted that Dr. Wharam’s role in the group made him an active participant clinical research that “led to dramatic increases in pediatric cancer survival rates.” Among his fields of interest was brachytherapy, a form of pediatric radiotherapy. He also developed the standard of care for rhabdomyosarcoma, a childhood cancer of the connective tissue that attaches muscles to bones. The landmark treatment employed both chemotherapy and radiation therapy.

“In the early 1990s, years before advanced radiosurgery equipment had been developed, Dr. Wharam innovated a way to deliver radiation very precisely to preserve vision for a toddler diagnosed with cancer in both eyes,” said the Hopkins press release.

Dr. Wharam was named acting director of the division of radiation oncology, and from 1994 to 2000 served as its director. In addition to his work, he oversaw the opening of the Kimmel Cancer Center’s Harry and Jeanette Weinberg Building and a satellite facility at Green Spring Station in Lutherville.

Dr. Wharam worked long days, said his wife of 50 years, the former Sheila Mairead Reese. “He’d be at work by 6:45 a.m. and would not come home until 8 or 9 at night. He stayed late because he wanted to make certain that the radiation and the markers were done precisely as he wanted.”

Dr. Wharam retired in 2016 from the faculty of the Department of Radiation Oncology and Molecular Radiation Sciences. After Dr. Wharam’s retirement, the Moody Wharam Professorship was established at Hopkins in his honor

Dr. Wharam lived in Timonium for 39 years before moving to Essex two years ago. He enjoyed sailing on the Chesapeake Bay. “When he was diagnosed with Lou Gehrig’s disease, he said he wanted to celebrate our 50th wedding anniversary and his 77th birthday. He did both,” Mrs. Wharam said.

He was a Knight of the Order of the Holy Sepulchre of Jerusalem and a longtime communicant of St. Joseph Catholic Church in Cockeysville, where a Mass of Christian burial was offered Thursday.

In addition to his wife, Dr. Wharam is survived by a son, James Franklin Wharam of Newton, Mass.; two daughters, Anne W. Thomas of Washington and Julia M. Whelan of Savannah, Ga.; a brother, Franklin D. Wharam of Richmond, Va.; and nine grandchildren.