麻豆传媒

Adapting radiation therapy to image-guided changes in tumors led to a 34% reduction in pneumonitis in patients with locally advanced lung cancer, as reported at the congress in Vienna.

The incidence of grade 2/3 pneumonitis (requiring treatment) decreased from 50% of patients in a historical control group treated without adaptive radiotherapy to 33% of 108 treated with tumor-adjusted radiotherapy. The rates of local and loco-regional control did not differ between patients treated with and without adaptive radiation therapy.

"The outcome of patients with locally advanced lung cancer is compromised by a high rate of local failure," Azza Khalil, MD, of Aarhus University Hospital in Denmark, said in a statement. "As we reduced the tumor margin using this adaptive strategy, we are testing whether we would be able now to increase the treatment doses to the tumor without affecting the incidence of the radiation pneumonitis and, hence, have a better outcome."

Traditionally, radiation oncologists have developed treatment plans for locally advanced lung cancer by using skeletal landmarks for targeting. With the adaptive approach, clinicians used daily 3D tumor imaging to position patients, adjusting accordingly in response to changes during the course of delivering the treatment. The approach resulted in more precise targeting and enabled use of smaller margins around the tumor to spare healthy tissue.

The study involved 108 patients treated with the adaptive technique since 2013, and 102 patients treated prior to 2013 without the use of adaptive radiotherapy. Adaptive radiotherapy was associated with a significant reduction in planning target volume (400 versus 509 cm³, P<0.0001) and mean lung dose of radiation (12.6 versus 13.8 Gy, P=0.004). After a median follow-up of 20 months, the investigators found a significantly lower incidence of pneumonitis (P<0.001) in the adaptive radiotherapy group. The incidence of local failure was 32% with adaptive radiotherapy and 36% without, and locoregional failure rates were 43% and 48%, respectively, with and without the adaptive approach.

Patients Highly Satisfied with High-Dose Brachytherapy for Local Prostate Cancer

Six months after treatment with a single high dose of brachytherapy, 77% of a small group of patients with localized prostate cancer said they were "extremely satisfied" with the treatment and quality of life, and the remaining 23% were "very satisfied."

During a median follow-up of 16 months, no grade 3 adverse events occurred in the 45 patients involved in the study. Six patients had grade 2 bowel or bladder adverse effects. In general, urinary urgency declined significantly during the first 6 months after treatment, and all of the men reported normal urinary and bowel function at 1 year.

"Our study demonstrates that patients do not suffer high toxicity or a worse quality of life than might be expected with other methods of delivering radiation treatment," said Alfonso Gomez-Iturriaga, MD, of Hospital de Cruces in Baracaldo, Spain.

"It is too early to say that this strategy can be used outside of the trial setting, but it seems quite clear that the toxicity and impact on quality of life are very low," he added. "Longer follow-up for at least 5 years is needed to demonstrate definite cancer control."

The study involved patients with localized, low- to intermediate-risk prostate cancer. Treatment consisted of a single 19-Gy dose of radiation, delivered directly to the tumor by means of catheters positioned with the aid of 3D ultrasound imaging. None of the patients had prior exposure to androgen-deprivation therapy.

The primary objectives of the current analysis were to evaluate safety and patient-reported outcomes. In addition to urinary and bowel function, sexual function did not change significantly from baseline to 1 year. Gomez-Iturriaga said 60% of the men reported normal sexual function at baseline, and they retained normal function a year later.

Cervical Cancer Treatment Takes Toll in Adverse Quality-of-Life Effects

About half of women treated for locally advanced cervical cancer reported bothersome adverse effects at some point during follow-up, data for 1,176 patients showed.

During a median follow-up of 27 months, 64% of the women reported fatigue at some point, 50% reported hot flushes, and 43% reported insomnia. Though bothersome, the effects were infrequently severe or disabling, representing 2% to 4% of cases.

"These symptoms could have a serious impact on patients' daily life, possibly influencing how they feel in their professional, social, and family life," said Stephanie Smet, MD, of the Medical University of Vienna. "More and more women diagnosed with this type of cancer are surviving for longer. This is a relatively young group of patients, so many will possibly face decades of coping with their symptoms."

Some women may have preexisting symptoms, possibly predating the cancer diagnosis, she pointed out. "It is difficult to distinguish whether and to what extent these symptoms are caused by the cancer itself, by the treatment, or by other factors. In most cases, it is probably a combination."

The patients included in the study were treated at 22 globally located centers from 2008 to 2015. All received standard-of-care treatment, consisting of chemoradiation, followed by MRI-guided brachytherapy.