PET-Guided Radiation Reduces Post-op Failure Rates in Recurrent Prostate Cancer
The decision to offer radiation after prostatectomy for patients with recurrent prostate cancer has been shown to be complex, and significant limitations of conventional imaging leave a need for more accurate radiation therapy decision making and treatment planning. Although the advanced PET radiotracer fluciclovine was approved in 2016 for use with PET imaging to help diagnose recurrence in men with treated prostate cancer and rising PSA levels, it is not currently used for radiation treatment planning. To shed light in this area, researchers randomized patients with recurrent prostate adenocarcinoma postprostatectomy 1:1 to radiotherapy based on standard imaging (controls) or radiotherapy based on standard imaging plus fluciclovine PET/CT (PET-guided). Failure-free survival rates at 3 years were 75.5% for those in the PET-guided group, compared with 63.0% in the control group; respective rates at 4 years were 75.5% and 51.2%. Grade 3 genitourinary adverse events were experienced by no patients in the PET-guided group and 3.7% in controls. Acute gastrointestinal toxicities were not observed in either group.
Stereotactic Radiosurgery Bests Whole-Brain Radiation Therapy for “Numerous” Brain Metastases
Although previous studies support stereotactic radiosurgery (SRS) as the standard of care in patients with cancer with up to three brain metastases due to better preservation of cognitive function and similar overall survival when compared with whole-brain radiation therapy (WBRT), whether SRS should be used for the many patients who present with numerous (4-15) brain metastases remains unclear. Between 2012 and 2019, researchers randomized patients with four to 15 brain metastases to SRS or WBRT. At 4 months, patients in the SRS group had an average z-score increase of 0.21 from baseline on the Hopkins Verbal Learning Test-Revised Total Recall, compared with a decline of 0.74 in the WBRT group. Patients in the SRS group also had statistically significant and clinically meaningful advantages in memory function over those in the WBRT group at 1 and 6 months. Overall survival in the intent-to-treat population was 7.8 months for those in the SRS arm, compared with 8.9 months in the WBRT arm. A clinically meaningful decline in cognitive function was experienced by 50% of the WBRT arm, compared with just 6% of the SRS arm. While 4-month local control rates favored SRS over WBRT (95% vs 87%), distant brain control rates favored WBRT over SRS (80% vs 60%).
Single Fraction an Effective Alternative to Multi-Fraction SBRT for Oligometastatic Lung Lesions Evidence suggests that patients with cancer who have limited lung metastases may be suitable for surgery or stereotactic body radiotherapy (SBRT). For a study, researchers assigned patients with metastatic solid cancer and no more than three lung metastases in a 1:1 ratio to a single 28 Gy fraction of SBRT or 48 Gy over four fractions. Grade 3 or greater adverse events (AEs) at 1 year were experienced in 5% of patients in the single fraction arm and 3% in the multi-fraction arm. Grade 3 AEs in the single-fraction arm included fatigue, chest pain, and loss of breath across two patients, with no fatal events, compared with one patient who had undiagnosed interstitial lung disease and died of pneumonitis within 3 months of SBRT in the multi-fraction arm. Esophagitis and dermatitis were significantly more frequent in the multi-fraction arm, whereas all other common toxicities were not significantly different between the two arms. Local control rates were 93% in the single-fraction arm and 95% in the multi-fraction arm, while disease-free survival rates were 59% and 60%, respectively. Overall 1-year survival rates were 95% in the single-fraction arm and 93% in the multi-fraction arm.
Novel RT Approach for Cervical Cancer Achieves Similar Disease Control & Less GI Toxicity than Current Standard
Previous research showed improvement in patient reported outcomes at 5 weeks and 1 year with intensity-modulated radiation therapy (IMRT) over conventional four-field pelvic irradiation in patients with cervical or endometrial cancer, but clarity on the long-term impacts of postoperative IMRT in this patient population is lacking. In hopes of providing clarity, study investigators randomized patients with cervical cancer treated with either type III hysterectomy with intermediate- or high-risk features or type I/II hysterectomy necessitating adjuvant chemoradiation therapy to three-dimensional conformal radiation therapy (3D-CRT) or image-guided IMRT (IG-IMRT). Although disease control was similar in both groups, 4-year GI toxicity-free survival rates were 78% in the adjuvant IG-IMRT group and 57% in the 3D-CRT group. And while pelvic relapse-free survival rates did not differ significantly between the groups (IG-IMRT, 73%; 3D-CRT, 68%), grades 2 (hazard ratio [HR], 0.53) and 3 (HR, 0.23) GI toxicity rates were significantly reduced with IG-IMRT.
Most Cancer Survivors Experience Treatment-Related Sexual Side Effects
With the input of radiation oncologists, medical oncologists, and surgeons, researchers developed a questionnaire including more than 25 questions focused on experiences with sexual side effects after cancer treatment and distributed it to adults with mostly breast (67%), prostate (16%), and endometrial (6%) cancers treated with chemotherapy (78%), radiation therapy (54%), and/or hormone therapy (47%). Among respondents, 87% reported some change after cancer treatment that negatively affected their sexual function or desire, with 53.8% reporting body image distortion, 73.4% with dyspareunia, and 42.3% unable to achieve orgasm. However, only 27.9% said they had been formally asked by their clinician about their sexual health, and only about 40% said they had been preemptively warned that their treatment may affect their sexual health. “The majority of respondents felt that they would like a standard questionnaire to initiate and guide a discussion on sexual health with their provider,” noted the presenting study author.
