Imaging, Therapy Advances Displacing Radiotherapy in Cancer Treatment Regimens 

For decades, the mainstays of cancer treatment were “cut, poison, or burn” — ie, surgery, systemic chemotherapy, or radiation therapy. But with the arrival and proliferation of newer treatments with fewer adverse effects, we are now seeing a decline in the use of radiotherapy, particularly as part of first-line treatment for newly diagnosed cancers.^1-3

Dose-limiting radiation toxicities such as mucositis, fatigue, nausea, vomiting, diarrhea, fibrotic scarring, and skin burns frequently preclude delivery of planned therapeutic or curative radiation doses. Longer-term pain syndromes, incontinence, infertility, and secondary cancers are also experienced by some patients treated with radiation.³ 

Targeting advances such as conformal and intensity-modulated radiotherapy have helped to ameliorate that situation by offering more precise irradiation of tumors and their micrometastatic margins while sparing patients’ healthy, nontarget tissues. But radiotherapy continues to involve the risk of severe side effects that degrade patients’ quality of life. 

Evolution of Cancer Treatments 

A growing arsenal of more recently developed anticancer treatment options is now allowing clinicians to focus more on minimizing or avoiding the risk of adverse treatment effects, better ensuring preservation of patients’ quality of life. Targeted therapies, immunotherapies, and other advances in cancer treatment offer favorable outcomes with fewer side effects than radiation treatments.^2,3 Advances in medical imaging and biomarker tests are making it possible to diagnose cancer at earlier stages, when it is more likely to be cured with surgery or targeted treatments, allowing some patients to delay or forego radiation.^4,5 

As a result of these factors, radiotherapy is increasingly used as a last resort, only in cases where other treatments have failed. Delay or watchful waiting before radiotherapy initiation for early-stage malignancies are options for a growing number of patients.⁶ 

Since 2004, first-line radiotherapy utilization had declined modestly across cancer types, and particularly for genitourinary, head and neck, and brain cancers, with absolute decreases of 12.4%, 10.3% and 9.6%, respectively (all, P ≤.001), according to a 2018 analysis.¹ Together, their relative share of radiotherapy treatments has declined by 42.5%.¹ (Radiotherapy use has held steady or very slightly increased for gastrointestinal, musculoskeletal, skin, and thoracic cancers during the same period.¹)

“These findings … highlight the changing role of radiation oncology during the first line of cancer care,” reported lead study author Trevor Royce, MD, MPH, of the Boston University School of Medicine, and coauthors.¹

Take thyroid cancer. More patients with thyroid cancer have earlier stage disease at diagnosis, challenging longstanding treatment dogmas and allowing clinicians to sidestep aggressive frontline therapies for many patients. A study published earlier this year showed that surgery without any radioiodine can cure thyroid cancer in cases with the lowest risk, challenging the standard of universal adjuvant postsurgical radioiodine.⁶  

Adjuvant postoperative radiotherapy in patients with prostate cancer is also declining, and is increasingly reserved for patients with high Gleason scores, locally advanced disease, and cancer-positive surgical margins after resection.⁵ Adjuvant radiation is under similar scrutiny for younger patients with hormone-sensitive localized breast cancer treated with endocrine therapy.⁴ 

The Changing Role of Radiation Oncology 

Concern about demand for radiation oncology professionals has already led to declines in applicants for clinical radiation oncology residency positions since 2019.⁷ 

Radiation oncology will evolve in the decades ahead, but will not disappear.⁸ Despite the decline in its use, radiotherapy will continue to be a mainstay of palliative pain-relief care and an important component of multidisciplinary cancer treatment strategies — albeit for a narrower range of carefully selected patients.  

References

1. Royce TJ, Qureshi MM, Truong MT. Radiotherapy utilization and fractionation patterns during the first course of cancer treatment in the United States from 2004 to 2014. J Am Coll Radiol. 2018;15(11):1558-1564. doi:10.1016/j.jacr.2018.04.032

2. Slachta A. Radiotherapy use during 1st phase of cancer treatment declining across US. Radiol Bus. Published June 12, 2018. Accessed October 18, 2023.

3. Chen A. Radiation, a mainstay of cancer treatment, begins a fade-out. STAT. Published August 15, 2023. Accessed October 18, 2023. 

4. Hong MJ, Lum SS, Dupont E, et al; SHAVE2 Investigators. Omission of radiation in conservative treatment for breast cancer: opportunity for de-escalation of care. J Surg Res. 2022;279:393-397. doi:10.1016/j.jss.2022.06.036

5. Sineshaw HM, Gray PJ, Efstathiou JA, Jemal A. Declining use of radiotherapy for adverse features after radical prostatectomy: results from the National Cancer Data Base. Eur Urol. 2015;68(5):768-774. doi:10.1016/j.eururo.2015.04.003

6. Leboulleux S, Bournaud C, Chougnet CN, et al. Thyroidectomy without radioiodine in patients with low-risk thyroid cancer. N Engl J Med. 2022;386(10):923-932.

7. Maas JA, Burnett OL III, Marcrom SR. Reasons for declining applicant numbers in radiation oncology from the applicants’ perspective: results from the applicant concerns and radiation oncology sources survey (ACROSS). Int J Radiat Oncol Biol Phys. 2021;111(2):317-327. doi:10.1016/j.ijrobp.2021.05.007

8. Baumann M, Ebert N, Kurth I, Bacchus C, Overgaard J. What will radiation oncology look like in 2050? A look at a changing professional landscape in Europe and beyond. Mol Oncol. 2020;14(7):1577-1585. doi:10.1002/1878-0261.12731