On the development of an interstitial radiation protocol for a multicenter consortium. Experience with permanent low-dose rate and temporary high-dose rate 125I implants in 'failed' and 'newly diagnosed' glioblastoma patients: quality assurance methodology and a possible future adjuvant for therapeutic enhancement

Quo Vadis Oncological Hyperthermia (2020)?

Heating as a medical intervention in cancer treatment is an ancient approach, but effective deep heating techniques are lacking in modern practice. The use of electromagnetic interactions has enabled the development of more reliable local-regional hyperthermia (LRHT) techniques whole-body hyperthermia (WBH) techniques. Contrary to the relatively simple physical-physiological concepts behind hyperthermia, its development was not steady, and it has gone through periods of failures and renewals with mixed views on the benefits of heating seen in the medical community over the decades. In this review we study in detail the various techniques currently available and describe challenges and trends of oncological hyperthermia from a new perspective. Our aim is to describe what we believe to be a new and effective approach to oncologic hyperthermia, and a change in the paradigm of dosing. Physiological limits restrict the application of WBH which has moved toward the mild temperature range, targeting immune support. LRHT does not have a temperature limit in the tumor (which can be burned out in extreme conditions) but a trend has started toward milder temperatures with immune-oriented goals, developing toward immune modulation, and especially toward tumor-specific immune reactions by which LRHT seeks to target the malignancy systemically. The emerging research of bystander and abscopal effects, in both laboratory investigations and clinical applications, has been intensified. Our present review summarizes the methods and results, and discusses the trends of hyperthermia in oncology.

GliaSite brachytherapy boost as part of initial treatment of glioblastoma multiforme: a retrospective multi-institutional pilot study

PURPOSE

To report on a retrospective analysis of the cumulative experience from eight institutions using the GliaSite Radiotherapy System as a brachytherapy boost in the initial management of glioblastoma multiforme.

METHODS AND MATERIALS

Eight institutions provided data on 20 patients with histologically proven glioblastoma multiforme with a median age of 59 years (range, 39-76) and median Karnofsky performance scale of 80 (range, 50-100). After maximal surgical debulking, patients were treated with GliaSite brachytherapy to a median dose of 50 Gy, followed by external beam radiotherapy to a median dose of 60 Gy (range, 46-60 Gy), for a cumulative dose escalation of 110 Gy (range, 84-130 Gy).

RESULTS

The average survival for this study population was 11.4 months (range, 4-29). When the patients' survival was compared with that of historical controls according to their Radiation Therapy Oncology Group recursive partitioning analysis class, the average survival was increased by 3 months (95% confidence interval, 0.23-4.9) corresponding to a 43% increase (p = 0.033). Three patients (14%) experienced Radiation Therapy Oncology Group Grade 3 central nervous system toxicity. Of the treatment failures, 50% were >2 cm from the edge of the balloon.

CONCLUSION

The results of this analysis have demonstrated that dose escalation (>100 Gy) with GliaSite is well tolerated and associated with minimal toxicity. Local control improved with the use of GliaSite brachytherapy. The putative survival advantage seen in this study needs to be interpreted with caution; nevertheless, the data provide sufficient justification to investigate the potential role of radiation dose escalation in conjunction with GliaSite in the initial treatment of glioblastoma multiforme.

GliaSite Brachytherapy for Treatment of Recurrent Malignant Gliomas:A Retrospective Multi-institutional Analysis

OBJECTIVE:

To review the cumulative experience of 10 institutions in treating recurrent malignant gliomas with the brachytherapy device, GliaSite Radiation Therapy System.

METHODS:

The patient population consisted of 95 patients with recurrent grade 3 or 4 gliomas, a median age of 51 years, and a median Karnofsky performance status score of 80. All patients had previously undergone resection and had received external beam radiotherapy as part of their initial treatment. After recurrence, each patient underwent maximal surgical debulking of their recurrent lesion and placement of an expandable balloon catheter (GliaSite) in the tumor cavity. The balloon was afterloaded with liquid 125I (Iotrex) to deliver a median dose of 60 Gy to an average depth of 1 cm with a median dose rate of 52.3 Gy/hr. Patients were carefully followed with serial magnetic resonance imaging and monthly examinations for tumor progression, side effects, and survival.

RESULTS:

The median survival for all patients, measured from date of GliaSite placement, was 36.3 weeks with an estimated 1 year survival of 31.1%. The median survival was 35.9 weeks for patients with an initial diagnosis of glioblastoma multiforme and 43.6 weeks for those with non- glioblastoma multiforme malignant gliomas. Analysis of the influence of various individual prognostic factors on patient survival demonstrated that only Karnofsky performance status significantly predicted for improved survival. There were three cases of pathologically documented radiation necrosis.

CONCLUSION:

Reirradiation of malignant gliomas with the GliaSite Radiation Therapy System after reresection seems to provide a modest survival benefit above what would be expected from surgery alone. This report not only confirms the initial results of the feasibility study but provides evidence that similar outcomes can be obtained outside of a clinical trial.

The Brain Tumor Cooperative Group NIH Trial 87-01: A Randomized Comparison of Surgery, External Radiotherapy, and Carmustine versus Surgery, Interstitial Radiotherapy Boost, External Radiation Therapy, and Carmustine

OBJECTIVE

The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas.

METHODS

The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. 125I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the 125I implantation plus external beam radiation and BCNU therapy.

RESULTS

The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of 125I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups.

CONCLUSION

We conclude that there is no long-term survival advantage of increased radiation dose with 125I seeds in newly diagnosed glioma patients.