Experience at a high-volume cancer center suggests that nonstereotactic body radiotherapy external beam reirradiation of the pelvis for cancer recurrence or for a second genitourinary malignancy is safe in patients with advanced cancer, and can achieve excellent and durable palliation of symptoms without severe radiation-induced morbidity. These patients are typically near the end of life, and palliation of their symptoms improves the quality of their remaining life.
Reirradiation of the genitourinary area with external beam radiation is debatable, with no existing guidelines, said lead investigator Sophia C. Kamran, MD, Harvard Radiation Oncology Program, Boston, at the 2016 Genitourinary Cancers Symposium. She reported the results of a retrospective review of 28 patients with locally advanced symptomatic disease (27 males, 1 female) who were reirradiated.
“Patients with genitourinary malignancies commonly receive radiation. Many may develop a recurrence or a secondary neoplasm. The cancer community may have concerns about the risk of bowel and bladder toxicity with external beam reirradiation of the pelvis. We showed that with careful planning, we can safely reirradiate the pelvic area and eliminate toxicity,” Dr Kamran said.
Patients had a variety of primary tumor types, including rectal, bladder, penile, prostate, ureteral, and large-cell lymphoma. For their primary disease, the patients were treated with radiation alone (47%), chemotherapy plus radiation (7%), radiation plus surgery (32%), or all 3 modalities (14%).
The patients were retreated with high-dose external beam pelvic reirradiation, defined as >50 Gy given with standard fractionation or hypofractionation that is bioequivalent to ≥50 Gy.
All patients had pain, bleeding, and/or bladder symptoms as indications for reirradiation. Effectiveness was scored according to reduction in these signs and symptoms. The treatment was carefully planned to increase precision and to avoid affecting critical normal organs using a variety of maneuvers depending on the case, including 4-dimensional simulation (N = 7), customized immobilization devices (N = 28), image-guided radiation delivery (N = 20), 3-dimensional conformal therapy (N = 20), and 2-dimensional therapy (N = 4).
The median overall survival was 5.8 months (range, 0.3-39 months), and death was secondary to systemic disease in all cases.
Excellent and durable palliation was observed after reirradiation. “Ninety-two percent of patients responded to reirradiation at high doses with resolution of their symptoms and limited toxicity,” Dr Kamran said.
No Radiation Therapy Oncology Group grade 3 or 4 treatment-related toxicity was reported.
“Many people assume this is not safe. We monitored patients’ symptoms weekly. Reirradiation provides great palliative therapy in patients with a recurrence or a new second cancer. They can enjoy good quality of life free of these symptoms near the end of life,” she stated.
“Meticulous treatment planning, with avoidance of sensitive structures, and short survival times may have contributed to the low morbidity we saw in this series. These results need to be validated in a prospective study with a larger number of patients,” Dr Kamran concluded.