Hypofractionated proton beam radiotherapy safe, beneficial f

[Hebbie]

Hypofractionated proton beam radiotherapy safe, beneficial for stage I lung cancer

Will Boggs, MD

Reuters Health

Posting Date: November 12, 2004

Last Updated: 2004-11-12 16:20:11 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Hypofractionated proton beam radiotherapy is safe and beneficial for stage I lung cancer patients unsuitable for surgical resection, according to a report in the October issue of Chest.

"The properties of proton therapy allow high dose tumor irradiation while sparing surrounding normal tissues, which can have profound effects on treatment outcomes in many tumor sites," Dr. David A. Bush from Loma Linda University Medical Center in California told Reuters Health.

Dr. Bush and colleagues studied the toxicity and efficacy of high-dose hypofractionated proton beam radiotherapy in 68 patients with clinical stage I lung cancer.

In the Kaplan-Meier analysis, the authors report, the 3-year estimated local control rate was 74%, the overall survival rate was 44%, and the disease-specific survival rate was 72%. At 3 years, 31% of patients had metastatic relapses.

These figures compare favorably with published 3-year overall survival rates of 32% and disease-specific survival of 43% with conventional radiotherapy, the authors note.

Three-year local control was better among patients with T1 tumors (87%) than among patients with T2 tumors (49%), the report indicates, and 3-year overall survival was higher for patients who received 60 cobalt Gray equivalents (CGE) (55%) than for those who received 51 CGE (27%).

Improved survival was also correlated with higher performance status and female gender, the researchers note.

Acute toxicities were minor, the investigators report, and there were no cases of acute radiation pneumonitis or acute or late esophageal or cardiac toxicity.

"Non-surgical therapy for stage-1 lung cancer is improving as technological advances are made in radiation therapy, such as proton therapy," Dr. Bush said. "This study has demonstrated reasonably good cancer specific survival with minimal toxicity. This option should be considered for patients with early stage lung cancer who are not suitable for, or refuse, surgical resection."

"We have been continuing to modify the treatment in an effort to improve outcomes," Dr. Bush added. "In an attempt to improve control rates in these patients, we have increased the dose to 70 Gy in 10 fractions. This is equivalent to about 100 Gy if given in a standard fractionated coarse of treatment. Some consideration is also being given to adding adjuvant chemotherapy, as it has recently been shown to be of benefit in surgical patients."

Chest 2004;126:1198-1203.