Early Career Radiation Oncologists Share Takeaways from ASTRO 2024

by Kelsey Corrigan, MD

ASTRO Early Career Committee members and colleagues attended this year’s ASTRO Annual Meeting in full force. I asked them to share one idea they picked up from the meeting that they could put into practice “tomorrow.”

Breast Cancer

A Randomized Trial of Hypofractionated Post-Mastectomy Radiation Therapy (PMRT) in Women with Breast Reconstruction (RT CHARM, Alliance A221505)

• Design: 50Gy/25fx vs 42.56Gy/16fx for PMRT in patients with pT0-2N1-2 or pT3N0 invasive breast cancer.
• 36 mo local or regional recurrences occurred in 1.5% of hypofractionated and 2.3% of conventional pts, p-value NSS.
• Acute and late toxicity rates were not statistically different between arms. 
• 24-mo incidence of reconstruction complications was 14% with hypofractionation vs 11.7% with conventional PMRT, P = 0.0005.
• Takeaway: We can move forward hypofractionation in the post-mastectomy setting.
• Takeaway: Have a conversation with breast surgery teams about the timing of RT when there is reconstruction, since some reconstructed patients pursue the expander-implant pathway that can be associated with higher complications, vs. autologous tissue. 
• Read More:https://www.redjournal.org/article/S0360-3016(24)00764-8/fulltext 

Head and Neck Cancer

Interim Futility Results of NRG-HN005, A Randomized, Phase II/III Non-Inferiority Trial for Non-Smoking p16+ Oropharyngeal Cancer Patients LBA 03

• Design: 70Gy over 6 weeks with concurrent cis (100mg/m2 q3w) (Arm 1) vs 60Gy over 6 weeks with concurrent cis (100mg/m2 q3w) (Arm 2) vs. 60Gy over 5 weeks with concurrent nivolumab (Arm 3) for definitive treatment in patients with pT1-2N1 or pT3N0-1 p16+ OPX SCC and ≤10 pack-yr smoking hx.
• At 2.2 years, 2-year PFS estimates are 98.1% for Arm 1, 88.6% for Arm 2, and 90.3% for Arm 3.
• Takeaway: 70Gy over 6 weeks with concurrent cis remains SOC. Trial will not proceed to phase III.
• Read More:https://www.redjournal.org/article/S0360-3016(24)03239-5/fulltext 

Hematological Cancer

Phase I Hypofractionation Trial of Relapsed/Refractory Lymphoma: Preliminary Results

• Takeaway: Hypofractionation in the treatment of lymphoma: More data supporting hypofractionation approaches in both the de novo and relapsed/refractory setting.
• Takeaway: Prospective phase I study (Rajeev Kumar et al) demonstrated safety of 23.4Gy/3fxs to treat relapsed/refractory lymphomas with favorable local control (100% at 1 year) and overall survival (85% at 1 year). One (5%) grade 3 toxicity reported.
• Read More:https://www.redjournal.org/article/S0360-3016(24)00876-9/fulltext

Initial Results of the Multicenter Phase II Trial of a Novel Hypofractionated Low-Dose Radiotherapy for Indolent Non-Hodgkin Lymphoma

• Takeaway: Prospective phase II study (Wang et al) demonstrated initial efficacy and minimal toxicity of 12Gy/4fxs for pts with follicular or marginal zone lymphomas. At median f/u of 8.7 months, there was a 92% complete response rate and 100% 6-month overall response rate. No grade 3 or greater AEs associated with RT.
• Read More:https://www.redjournal.org/article/S0360-3016(24)00924-6/fulltext

Optimizing Low Dose Radiotherapy for Indolent Lymphomas: Comparing 4 Gy x 2 vs. 2 Gy x 2

• Takeaway: Retrospective study (Burlile et al) comparing 8Gy/2fxs v. 4Gy/2fxs in pts with low-grade B cell lymphomas, found numerically lower rates of local recurrence in the 8Gy group (7% vs. 26%).
• Read More:https://www.redjournal.org/article/S0360-3016(24)03038-4/fulltext
• Ultra-Hypofractionated Involved Site Radiation Therapy (ISRT) as Salvage or Bridging Therapy in Aggressive Non-Hodgkin Lymphomas
• Retrospective study (Veeramachaneni et al) reported on the use of ultra-hypofractionated ISRT (most common dose was 30Gy/5fxs) as salvage (post initial therapy or CAR-T) or bridging therapy in pts with aggressive non-Hodgkin lymphoma, and demonstrated excellent local control (96%).
• Takeaway: Ultra-hypofractionated ISRT is safe and effective in nHL, and allows patients to quickly move on to next-line therapy when indicated. 
• Read More:https://www.redjournal.org/article/S0360-3016(24)03100-6/fulltext

Genitourinary Cancer

Prostate Advanced Radiation Technologies Investigating Quality of Life (PARTIQoL): Phase III Randomized Clinical Trial of Proton Therapy vs. IMRT for Localized Prostate Cancer

• Design: IMRT vs. proton beam therapy (79.2Gy/44fxs or 70Gy/28fxs for either modality) in pts with low- or intermediate-risk prostate cancer.
• At 24 mo, no difference between protons or IMRT in mean change of bowel score (p=0.836). No difference in bowel function at earlier timepoints (3, 6, 9, 12, 18 mo) or later timepoints (36, 48, 60 mo).
• No differences were observed in other domains (urinary, sexual, hormonal) at any timepoint.
• No difference in PFS (93.7% for IMRT vs 93.4% for protons at 60 mo, HR 1.16 [0.53, 2.57], p=0.706). 
• Takeaway: No measurable differences between IMRT and proton therapy in low- or intermediate-risk prostate cancer.
• Read More:https://www.redjournal.org/article/S0360-3016(24)03237-1/fulltext

Outcomes of Radium-223 and SABR vs. SABR for oligometastatic prostate cancers – The RAVENS Phase II Randomized Trial

• Design: SBRT to bone mets as mets-directed therapy vs. SBRT + Ra223 in men with oligometastatic hormone-sensitive prostate cancer (≥ 1 bone met with ≤5 radiation fields).
• Median PFS was 10.2 months with SBRT and 10.4 months with SBRT/Ra223 (stratified HR 1.7, 95% CI, 0.78-3.69, p = 0.18).
• Takeaway: Addition of Ra223 to SBRT for mets-directed therapy in low volume metastatic prostate cancer patients does NOT delay progression of disease. SBRT alone remains SOC.
• Read More:https://www.redjournal.org/article/S0360-3016(24)03246-2/fulltext

Lung Cancer

Concurrent Chemoradiation ± Atezolizumab (atezo) in Limited-stage Small Cell Lung Cancer (LS-SCLC): Results of NRG Oncology/Alliance LU005

• Design: Concurrent chemoRT (CRT; 45Gy BID or 66 Gy daily RT allowed; chemo was platinum/etop) vs. concurrent chemoRT with atezo in pts with limited stage small cell lung carcinoma. All patients received consolidation atezo.
• Median OS was 39.5 mos for CRT and 33.1 mos for atezo+CRT (HR= 1.11, 95% CI: 0.85-1.45).
• Median PFS was 11.5 mos for CRT and 12.0 mos for atezo+CRT (HR=1.00, 95% CI: 0.80-1.25). 
• Grade 3+ pneumonitis was 3.1% for CRT and 5.6% for atezo+CRT.
• Regardless of the receipt of atezo, pts treated with BID radiation had higher survival (median OS 35.4 mos) than daily RT (median OS 28.3) (HR=1.44, 95% CI: 1.10-1.89).
• Takeaway: CRT with concurrent and consolidation atezo did not improve survival in limited stage SCLC. CRT followed by atezo remains SOC.
• Takeaway: Also, pts treated with BID radiation may have better survival as compared to those treated with daily RT.
• Read More:https://www.redjournal.org/article/S0360-3016(24)03238-3/fulltext

Benign Diseases

Low Dose Radiation Therapy for Osteoarthritis: A Retrospective Single Institution Analysis of 51 Patients and 85 Joints

• One retrospective study looked at 51 patients with osteoarthritis, involving 85 affected joints. Distribution of treated joints: 32 hands, 7 shoulders, 1 elbow, 8 hips, 32 knees, and 5 feet/ankles.
• Each patient received a total dose of 3 Gy delivered in fractions of 0.5 Gy qod.
• 72% of patients experienced a significant improvement in pain and functionality. Pain scores were notably reduced, and patients reported enhanced joint mobility and daily functioning.
• Takeaway: Consider incorporating low dose radiation therapy for treatment of osteoarthritis. 
• Read More:https://www.redjournal.org/article/S0360-3016(24)01461-5/fulltext