Accelerated hyperfractionated irradiation for advanced head and neck cancer: effect of shortening the median treatment duration by 13 days

Treatment Delays in Primarily Resected Oropharyngeal Squamous Cell Carcinoma: National Benchmarks and Survival Associations

OBJECTIVE

To characterize treatment delays in surgically treated oropharyngeal cancer, identify factors associated with delays, and associate delays with survival.

STUDY DESIGN

Retrospective cross-sectional analysis.

SETTING

Commission on Cancer-accredited institutions.

SUBJECTS AND METHODS

We identified patients in the National Cancer Database with surgically treated oropharyngeal cancer. We characterized the durations of diagnosis-to-treatment initiation, surgery-to-radiation treatment, radiation treatment duration, total treatment package, and diagnosis-to-treatment end intervals as medians. We associated delays with patient, tumor, and treatment factors via multivariable logistic regression analysis and with overall survival by Cox proportional hazards regression.

RESULTS

In total, 3708 patients met inclusion criteria. Median durations of diagnosis-to-treatment initiation, surgery-to-radiation treatment, radiation treatment duration, total treatment package, and diagnosis-to-treatment end intervals were 27, 42, 47, 90, and 106 days, respectively. Medicaid and human papillomavirus (HPV) negativity were associated with delays. Delayed total treatment package and diagnosis-to-treatment end intervals were associated with decreased survival (hazard ratio [HR] = 1.81 [1.29-2.54], P = .001 and HR = 1.97 [1.39-2.78], P < .001, respectively); this was maintained following HPV stratification. Delays in the surgery-to-radiation treatment interval were associated with decreased overall survival in HPV-negative but not HPV-positive patients (HR = 2.05 [1.19-3.52], P = .010 and HR = 1.15 [0.74-1.80], P = .535, respectively). Diagnosis-to-treatment initiation and radiation treatment duration were not associated with overall survival in the overall cohort (HR = 1.21 [0.86-1.72], P = .280 and HR = 1.40 [0.99-1.99], P = .061, respectively); however, following stratification, delayed radiation treatment duration approached significance in HPV-negative but not HPV-positive patients (HR = 1.60 [0.96-2.68], P = .072 and HR = 1.35 [0.84-2.18], P = .220).

CONCLUSION

Treatment durations identified here can serve as national benchmarks and for institutions to compare quality to their peers. Distinct benchmarks should be applied to HPV-negative and HPV-positive patients.

Treatment delays in oral cavity squamous cell carcinoma and association with survival

BACKGROUND

Treatment durations and factors associated with delays for oral cavity squamous cell carcinoma (SCC) have previously been described but are not fully understood. Impact of delays on overall survival (OS) remains unclear.

METHODS

The National Cancer Data Base (NCDB) was used to analyze 4868 patients with oral cavity SCC from 1998 to 2011. Diagnosis-to-surgery, surgery-to-radiotherapy (RT)_start , RT duration, total treatment package (surgery-to-RT_end ), and diagnosis-to-RT_end were evaluated. Associations between delays and various factors were analyzed using binary logistic regression. Associations with OS were analyzed using the Cox proportional hazards model.

RESULTS

Medians for diagnosis-to-surgery, surgery-to-RT_start , RT duration, total treatment package, and diagnosis-to-RT_end were 30, 50, 49, 101, and 136 days, respectively. Age ≥60 years, uninsured or Medicaid insurance, comorbidity, late pT, and treatment at an academic/research institution were associated with diagnosis-to-surgery delays. Only delays in RT duration were significantly associated with decreased OS (hazard ratio [HR] = 1.21; p = .02).

CONCLUSION

Numerous factors are associated with treatment delays. RT duration is significantly associated with OS. © 2017 Wiley Periodicals, Inc. Head Neck 39: 639-646, 2017.

Concurrent hyperfractionated chemoradiotherapy for head and neck squamous cell carcinoma: the prognostic impact of the overall treatment time and completion rates of chemotherapy

The purpose of this study was to investigate whether the overall treatment time and completion rates of chemotherapy were predictive factors for the survival rates in patients with squamous cell carcinoma of the head and neck (SCCHN) who were treated with concurrent chemoradiotherapy (CCRT) using hyperfractionated radiotherapy (RT) and daily carboplatin. The number of intermission days of RT were as follows; 0 (n = 37), 1–5 (n = 8), 6–10 (n = 12) and ≥11 (n = 12), and the days of RT without carboplatin; 0 (n = 27), 1–5 (n = 13), 6–10 (n = 13) and ≥7 (n = 16). The overall treatment time (≤48 vs ≥49 days) was a significant prognostic factor for the local control, disease-free survival and overall survival rates. The completion rate of chemotherapy, as the number of days of RT without carboplatin, was not a significant factor affecting any of the survival rates. In discussion, the strengths of the present study contain that all the patients were treated with 72 Gy delivered as 1.2 Gy twice daily, and received concurrent chemotherapy comprising daily carboplatin as a radio-sensitizer. Based on the results, the completion rate of chemotherapy may have a lower impact on the local control rate in comparison with the overall treatment time. We believe that when a treatment interruption is needed because of the acute toxicities, hyperfractionated RT should be resumed as soon as possible independently while continuing the break of daily carboplatin. The overall treatment time influenced the clinical outcomes in SCCHN patients treated with hyperfractionated CCRT using carboplatin, while the impact of the completion rates of daily carboplatin was limited. Sixty-nine consecutive patients with SCCHN were initially treated with definitive CCRT and were retrospectively analyzed. All 69 patients were treated with CCRT using hyperfractionated RT of 72 Gy in 60 fractions and daily carboplatin (25 mg/m²). The patients treated with other chemotherapeutic regimens or induction chemotherapy were excluded. On the intermission days of the RT, carboplatin was not prescribed. After the intermission, CCRT using RT plus daily carboplatin or RT alone was resumed.

21 years of biologically effective dose

In 1989 the British Journal of Radiology published a review proposing the term biologically effective dose (BED), based on linear quadratic cell survival in radiobiology. It aimed to indicate quantitatively the biological effect of any radiotherapy treatment, taking account of changes in dose-per-fraction or dose rate, total dose and (the new factor) overall time. How has it done so far? Acceptable clinical results have been generally reported using BED, and it is in increasing use, although sometimes mistaken for "biologically equivalent dose", from which it differs by large factors, as explained here. The continuously bending nature of the linear quadratic curve has been questioned but BED has worked well for comparing treatments in many modalities, including some with large fractions. Two important improvements occurred in the BED formula. First, in 1999, high linear energy transfer (LET) radiation was included; second, in 2003, when time parameters for acute mucosal tolerance were proposed, optimum overall times could then be "triangulated" to optimise tumour BED and cell kill. This occurs only when both early and late BEDs meet their full constraints simultaneously. New methods of dose delivery (intensity modulated radiation therapy, stereotactic body radiation therapy, protons, tomotherapy, rapid arc and cyberknife) use a few large fractions and obviously oppose well-known fractionation schedules. Careful biological modelling is required to balance the differing trends of fraction size and local dose gradient, as explained in the discussion "How Fractionation Really Works". BED is now used for dose escalation studies, radiochemotherapy, brachytherapy, high-LET particle beams, radionuclide-targeted therapy, and for quantifying any treatments using ionising radiation.

Is There an Optimum Overall Time for Head and Neck Radiotherapy? A Review, with New Modelling

AIMS

To test by modelling whether a non-standard fractionated schedule giving optimum log cell kill could be expected, between short (accelerated) and longer multiple fraction/day schedules.

MATERIALS AND METHODS

Linear quadratic modelling was carried out for many schedules, with biologically effective doses converted to normalised total doses (NTDs; in 2 Gy fractions). Late complication and acute mucosal NTDs were calculated as constraint doses for each schedule, and the highest tumour NTDs and log cell kill values within both constraints were calculated. This modelling is robust and agrees with conclusions in a very recent meta-analysis (Bourhis J, Overgaard J, Audry H, et al. Hyperfractionated or accelerated radiotherapy in head and neck cancer: a meta-analysis. www.thelancet.com. Published online August 17, 2006).

RESULTS

The six schedules that gave the highest tumour log cell kill deliver a narrow range of 11.1-11.2 log10 cell kill in the present parameters. Other regularly used schedules give closer to 10 log10. Using one fraction/day fails to achieve the highest therapeutic ratios. Suggestions are made for escalating certain UK schedules. Fractionated radiotherapy results in a nearly constant tumour cell kill if the acute mucosal NTD is held constant. However, a small (3%) gain in tumour cell kill occurs from 3 weeks to 73 fractions of 1.15 Gy in 7 weeks. That is how fractionation works, within both acute and late constraints. Short accelerated schedules enable fewer late complications, but do not do as well for the minority of head and neck tumours that repopulate slowly.

CONCLUSIONS

Schedules of 4-6 weeks overall time could be chosen to give at least 11 log10 cell kill, which are safe. Most tumours would require two fractions/day, until routine monitoring of repopulation rates becomes feasible to select individual tumours. There is no 'optimum schedule', but each chosen schedule can be balanced against its own risk of excessive acute or late complications, as shown in these examples.

Acute radiation reactions in oral and pharyngeal mucosa: tolerable levels in altered fractionation schedules

PURPOSE

To investigate whether a predictive estimate can be obtained for a 'tolerance level' of acute oral and pharyngeal mucosal reactions in patients receiving head and neck radiotherapy, using an objective set of dose and time data.

MATERIALS AND METHODS

Several dozen radiotherapy schedules for treating head and neck cancer have been reviewed, together with published estimates of whether they were tolerated or (in a number of schedules) not. Those closest to the borderline were given detailed analysis. Total doses and biologically effective doses (BED or ERD) were calculated for a range of starting times of cellular repopulation and rates of daily proliferation. Starting times of proliferation from 5 to 10 days and daily cellular doubling rates of 1-3 days were considered. The standard published form of BED with its linear overall time factor was used: BED=nd(1 + d/(alpha/beta) - Ln2(T - T(k))/alpha T(p) (see text for parameters).

RESULTS

A clear progression from acceptable to intolerable mucosal reactions was found, which correlated with total biologically effective dose (BED in our published modeling), for all the head and neck cancer radiotherapy schedules available for study, when ranked into categories of 'intolerable' or 'tolerable'. A review of published mechanisms for mucosal reactions suggested that practical schedules used for treatment caused stimulated compensatory proliferation to start at about 7 days. The starting time of compensatory proliferation had little predictive value in our listing, so we chose the starting time of 7 days. Very short and very long daily doubling rates also had little reliability, so we suggest choosing a doubling time of 2.5 days as a datum. With these parameters a 'tolerance zone of uncertainty' could be identified which predicted acute-reaction acceptability or not of a schedule within a range of about 2-10 Gy in total BED. If concurrent chemoradiotherapy is used, our provisional suggestion is that this zone should be reduced by up to roughly 3-5 Gy10 in BED, with a request for further evidence.

CONCLUSIONS

It is suggested that total BED should be used, as specified above. Parameters of alpha=0.35 Gy-(1), alpha/beta=10 Gy, Tk=7 days and Tp=2.5 days are suggested. The 'acute/ tolerance zone' then turns out to be 59-61 Gy10 for radiation-only treatments. Further information about the decrement caused by concurrent head-and-neck cancer chemoradiotherapy, possibly 3-5 Gy10, is required.

Accelerated superfractionated radiotherapy with concomitant boost for invasive bladder cancer

PURPOSE

To determine the toxicity and clinical effectiveness of accelerated superfractionated radiotherapy with delayed concomitant boost (ASCBRT) in locally invasive carcinoma of the bladder.

METHODS AND MATERIALS

Between July 1997 and December 2001, 87 patients (unsuitable or refusing cystectomy) with invasive bladder cancer underwent ASCBRT. The mean patient age was 66 years (range 40-90). The stage distribution was as follows: 2 T1, 51 T2, 13 T3, and 21 T4. Initially, the whole pelvis was treated by 1.8-Gy conventional daily fractions up to a total dose of 45 Gy. A small field boost covering gross disease was added as a second daily fraction (1.5 Gy) during the last 3 weeks of the 5-week schedule up to a total dose of 67.5 Gy. The interfraction interval was a minimum of 6 h. The patients were evaluated in follow-up for toxicity, local control, and survival.

RESULTS

All but 2 patients completed the study protocol. Grade 3 acute urinary toxicity was observed in 2 patients. Grade 2 and 3 late bladder toxicity was observed in 12 patients and 1 patient, respectively. Grade 2 and 3 late bowel toxicity was observed in 5 and 3 patients, respectively. The 3-year actuarial local control, distant disease control, cause-specific survival, and overall survival rate was 64%, 78%, 58%, and 46%, respectively. Multivariate analysis revealed T stage as independent predictor of complete response. For Stage T2 and T3, the 3-year local control rate was 77% and 48%, respectively. At the last follow-up, 53 patients (61%) were still alive with a survival time between 6 and 62 months.

CONCLUSION

ASCBRT is feasible with acceptable tolerance even in relatively old patients with Stage T3 or greater tumor. The encouraging locoregional control and survival results of this institutional experience, favorable compared with conventional radical and other accelerated fractionated (with or without a concomitant boost) RT series, make ASCBRT worthy of further study in a Phase III trial.